Re: [RE-wrenches] Electric Water kWh/ person

2018-03-20 Thread solar1online 
Ray, Chris, et al,

Both Paloma (185,500 BTU/h) and Bosch (117,000 BTU/h) manufactured
natural draft heaters that used zero electric, just like common tanks.
Because the majority of these units used a standing pilot, they were
castigated by the energy bureaucrat folks in favor of something that
used some electronics to create a spark. Complexity. Then to get the
unit bigger (max ~200,000 BTU/h) for non-boiler applications, a power
vent was added (more complexity) and in due time an electrically
driven gas valve (yet more complexity). To help keep the heater from
freezing when the installation was not done properly, electric ceramic
heaters were added to the heat exchanger to minimize freezing (~300 w
temperature activation). 

The way these non electric natural draft tankless heaters were used in
Europe and Asia was to turn off even the pilot once you were finished
using the water heater (they had the piezo (BBQ style) sparker that
was integrated with the unit as factory equipment). Energy efficient
and simple. There are rare non electric units still available
(sometimes at a premium) if you look hard in the US. Alternatively,
look no further than Canada and Mexico for the same non electric Bosch
models outlawed in the US. The Paloma has been out of production for
some time, so when my remaining new natural gas units are gone, I will
not be able to get any more either. 

Best wishes,
Bill Loesch
314 631 1094

-From: "Ray" 
To: 
Cc: 
Sent: 20-Mar-2018 21:15:19 +
Subject: Re: [RE-wrenches] Electric Water kWh/ person

Rianai have 3 major issues when used off grid. 

1) The phantom load when I checked was over 30 watts continuous.
That's over 700 w-hr/ day. 

2) They need pure sine wave, and even have trouble on Trace SW
inverters. (One system I took over has a separate Exeltech on its own
battery and AC charger to run the Rianai, since they have Trace
inverters. Talk about a waste!)

3) They still have the hard well water scaling issues. 

Ray 

Remote Solar

  On 3/20/18 12:03 PM, Dana wrote:

It used to be that “tankless” water heaters were very sensitive
to stable temperature production as flows from single handle facets
shut down the hot and opened the cold flows. 

I can fully recommend the Rianai heaters of today as we have 2 in
offgrid and 0 issues. I have family members that have had them in
residential homes for several years also and 0 issues. 

They do require 120 vac & have digital controls. The water
temperature is very stable & consistent. I have not measured the
phantom load but could if someone needs to know. 

2 thumbs up for Rianai heaters from MHO. 





Dana Orzel Great Solar Works, Inc.  

C - 208.721.7003 d...@solarwork.com [1] 

Idaho Contractor - # 028765 Idaho PV # 028374 

NABCEP # 051112-136 www.solarwork.biz [2] 

"Responsible Technologies for Responsible People since 1988"  

P Please consider the environment before printing this email. 

FROM: RE-wrenches  [3] ON BEHALF OF cwarfel
 SENT: Tuesday, March 20, 2018 11:48 AM
 TO: re-wrenches@lists.re-wrenches.org [4]
 SUBJECT: Re: [RE-wrenches] Electric Water kWh/ person   

What are the issues with tankless water heaters? I have heard them
described as having "issues", but I haven't read anything that
describes what they are. They are very popular where I live. Any info?
Thanks, Chris 

On 3/20/2018 1:07 PM, Dave Angelini Offgrid Solar wrote:   

And a big maybe for Offgrid where we like multiple ways to 

charge/heat/cool and make hot water. The default method is almost
always 

the most reliable. For a typical home a 50 gallon propane tank water 

heater with a zinc change every 7 years is the norm. 

An air to water heat pump, an open loop solar water panel or closed
loop 

if conditions warrant it are great secondary methods. To me heating
water 

with electricity does not work because of winter and is a last thing
to 

add.A tankless and their issues are near the end of the list. Ground 

source heat pumps are even lower to me with very nice prices on
extremely 

efficient mini split air source pumps. 

I always try and minimize generators but if you need them then it
allows 

one to have more options. 

Dave Angelini Offgrid Solar 

"we go where powerlines don't" 

 [5]http://members.sti.net/offgridsolar/ [6] 

e-mail offgridso...@sti.net [7] 

text 209 813 0060 

Maybe. I designed my own house to incorporate this. The most
efficient are 

the vertical type, and at 6' the company advertised 20% recovery for
about 

$1,300 if I remember c

Re: [RE-wrenches] Electric Water kWh/ person

2018-03-20 Thread Ray 

Rianai have 3 major issues when used off grid.

1) The phantom load when I checked was over 30 watts continuous. That's 
over 700 w-hr/ day.


2) They need pure sine wave, and even have trouble on Trace SW 
inverters.  (One system I took over has a separate Exeltech on its own 
battery and AC charger to run the Rianai, since they have Trace 
inverters.  Talk about a waste!)


3) They still have the hard well water scaling issues.

Ray

Remote Solar


On 3/20/18 12:03 PM, Dana wrote:


It used to be that “tankless” water heaters were very sensitive to 
stable temperature production as flows from single handle facets shut 
down the hot and opened the cold flows.


I can fully recommend the Rianai heaters of today as we have 2 in 
offgrid and 0 issues. I have family members that have had them in 
residential homes for several years also and 0 issues.


They do require 120 vac & have digital controls. The water temperature 
is very stable & consistent. I have not measured the phantom load but 
could if someone needs to know.


2 thumbs up for Rianai heaters from MHO.



Dana Orzel  Great Solar Works, Inc.

*C - 208.721.7003  d...@solarwork.com*

Idaho Contractor - # 028765 Idaho PV # 028374

NABCEP # 051112-136 www.solarwork.biz <http://www.solarwork.biz>

_"Responsible Technologies for Responsible People since 1988" ___

*P*Please consider the environment before printing this email.

*From:*RE-wrenches <re-wrenches-boun...@lists.re-wrenches.org> *On 
Behalf Of *cwarfel

*Sent:* Tuesday, March 20, 2018 11:48 AM
*To:* re-wrenches@lists.re-wrenches.org
*Subject:* Re: [RE-wrenches] Electric Water kWh/ person

What are the issues with tankless water heaters?  I have heard them 
described as having "issues", but I haven't read anything that 
describes what they are.  They are very popular where I live.  Any 
info? Thanks, Chris


On 3/20/2018 1:07 PM, Dave Angelini Offgrid Solar wrote:

And a big maybe for Offgrid where we like multiple ways to

charge/heat/cool and make hot water. The default method is almost always

the most reliable. For a typical home a 50 gallon propane tank water

heater with a zinc change every 7 years is the norm.

An air to water heat pump, an open loop solar water panel or closed loop

if conditions warrant it are great secondary methods. To me heating water

with electricity does not work because of winter and is a last thing to

add.A tankless and their issues are near the end of the list. Ground

source heat pumps are even lower to me with very nice prices on extremely

efficient mini split air source pumps.

I always try and minimize generators but if you need them then it allows

one to have more options.

Dave Angelini Offgrid Solar

"we go where powerlines don't"

http://members.sti.net/offgridsolar/

e-mailoffgridso...@sti.net <mailto:offgridso...@sti.net>

text 209 813 0060

Maybe. I designed my own house to incorporate this. The most efficient 
are

the vertical type, and at 6' the company advertised 20% recovery for 
about

$1,300 if I remember correctly. This I'm sure is for a new copper pipe,

and

anyone who's ever taken apart a sewer pipe after a few years will know 
all

pipes get a bacterial mat of a couple mm thick. I suspect this might be 
a

pretty good insulator. At any rate there is a whole lot of copper 
involved

and associated inherent environmental challenges. I can't help but think

for the house design challenge to accommodate such a long perfectly

vertical pipe and expense another kW or more of solar would offset more

energy.

On Tue, Mar 20, 2018 at 9:50 AM, Drake

<drake.chamber...@redwoodalliance.org
<mailto:drake.chamber...@redwoodalliance.org>

wrote:

Daniel,

That sounds like an intriguing technology, much along the lines of 
an

air

to air heat exchanger. Thanks for the recommendation.  These systems

could

keep a lot of CO2 out of the atmosphere if widely used.

Drake

At 10:09 AM 3/19/2018, you wrote:

Content-Type: multipart/alternative;

  boundary="=_NextPart_000_0077_01D3BF6A.5EF88420"

Content-Language: en-us

Drake,

Have you or the client looked into the drainwater heat recovery 
units?

They make both a vertical and horizontal mounted version. They just 
help

recover the waste heat from shower water going down the drain.

My understanding is that economically they are barely past the 
breakeven

point when considering offsetting grid p

Re: [RE-wrenches] Electric Water kWh/ person

2018-03-20 Thread Dana 
It used to be that “tankless” water heaters were very sensitive to stable 
temperature production as flows from single handle facets shut down the hot and 
opened the cold flows.

I can fully recommend the Rianai heaters of today as we have 2 in offgrid and 0 
issues. I have family members that have had them in residential homes for 
several years also and 0 issues.

They do require 120 vac & have digital controls. The water temperature is very 
stable & consistent. I have not measured the phantom load but could if someone 
needs to know.

2 thumbs up for Rianai heaters from MHO.

 



Dana Orzel  Great Solar Works, Inc. 

C - 208.721.7003   d...@solarwork.com

Idaho Contractor - # 028765 Idaho PV # 028374

NABCEP # 051112-136<http://www.solarwork.biz> 
www.solarwork.biz

"Responsible Technologies for Responsible People since 1988"  

P Please consider the environment before printing this email.

 

 

From: RE-wrenches <re-wrenches-boun...@lists.re-wrenches.org> On Behalf Of 
cwarfel
Sent: Tuesday, March 20, 2018 11:48 AM
To: re-wrenches@lists.re-wrenches.org
Subject: Re: [RE-wrenches] Electric Water kWh/ person

 

What are the issues with tankless water heaters?  I have heard them described 
as having "issues", but I haven't read anything that describes what they are.  
They are very popular where I live.  Any info? Thanks, Chris

 

On 3/20/2018 1:07 PM, Dave Angelini Offgrid Solar wrote:

And a big maybe for Offgrid where we like multiple ways to
charge/heat/cool and make hot water. The default method is almost always
the most reliable. For a typical home a 50 gallon propane tank water
heater with a zinc change every 7 years is the norm.
 
An air to water heat pump, an open loop solar water panel or closed loop
if conditions warrant it are great secondary methods. To me heating water
with electricity does not work because of winter and is a last thing to
add.A tankless and their issues are near the end of the list. Ground
source heat pumps are even lower to me with very nice prices on extremely
efficient mini split air source pumps.
 
I always try and minimize generators but if you need them then it allows
one to have more options.
 
Dave Angelini Offgrid Solar
"we go where powerlines don't"
http://members.sti.net/offgridsolar/
e-mail  offgridso...@sti.net <mailto:offgridso...@sti.net> 
text 209 813 0060
 

Maybe. I designed my own house to incorporate this. The most efficient are
the vertical type, and at 6' the company advertised 20% recovery for about
$1,300 if I remember correctly. This I'm sure is for a new copper pipe,
and
anyone who's ever taken apart a sewer pipe after a few years will know all
pipes get a bacterial mat of a couple mm thick. I suspect this might be a
pretty good insulator. At any rate there is a whole lot of copper involved
and associated inherent environmental challenges. I can't help but think
for the house design challenge to accommodate such a long perfectly
vertical pipe and expense another kW or more of solar would offset more
energy.
 
On Tue, Mar 20, 2018 at 9:50 AM, Drake
<drake.chamber...@redwoodalliance.org 
<mailto:drake.chamber...@redwoodalliance.org> 

wrote:

 

Daniel,
 
That sounds like an intriguing technology, much along the lines of an
air
to air heat exchanger. Thanks for the recommendation.  These systems
could
keep a lot of CO2 out of the atmosphere if widely used.
 
Drake
 
 
At 10:09 AM 3/19/2018, you wrote:
 
Content-Type: multipart/alternative;
 boundary="=_NextPart_000_0077_01D3BF6A.5EF88420"
Content-Language: en-us
 
 
Drake,
 
Have you or the client looked into the drainwater heat recovery units?
They make both a vertical and horizontal mounted version. They just help
recover the waste heat from shower water going down the drain.
 
My understanding is that economically they are barely past the breakeven
point when considering offsetting grid power. If using PV costs as the
benchmark, the economics would be better. If somehow this is off grid,
then
I’d say it’s a home run. (Hopefully though this is not an
all-electric
off-grid building.)
 
The main benefit, as far as I understand it, is that you can get by with
a
smaller unit, with a smaller heating element to perform the same task,
OR
you can get much longer showers from the same sized unit. Depending on
the
clients goals, this might be a useful tool to bring into the situation.
 
Here are two brand names that I know of.
Vertical mount: renewability
Horizontal mount: ecodrain
 
I have not used these products, so I cannot endorse any of them, just
though it may be worth consideration.
 
With Regards,
 
Daniel Young,
NABCEP Certified PV Installation ProfessionalTM: Cert #031508-90
 
*From:* RE-wrenches  <mailto:re-wrenches-boun...@lists.re-wrenche

Re: [RE-wrenches] Electric Water kWh/ person

2018-03-20 Thread cwarfel 
Ah,off grid. I see. That makes sense. I wouldn't use it place of solar, 
but we have used it as part of one. Obviously we have a tank in that 
application. We have a very good propane sales person herewho has sold a 
lot of on demand radiant and hydronic.It's almost twice thecost per BTU 
v oil, but they have done very well on low maintenance claims.



On 3/20/2018 1:58 PM, Dave Angelini Offgrid Solar wrote:

Chris,

For Offgrid with minerals in the well water, getting the right flow, the
maintenance that is just not there with a tank heater. Tankless are great
for many but if you do add an open loop solar water panel, you need a
tank Just not worth it in places like the south west where there is
abundant sunshine. Offgrid in remote places where service is questionable
or unavailable, we go with the most reliable. I steer them that way for
other reasons also..

Dave Angelini Offgrid Solar
"we go where powerlines don't"
http://members.sti.net/offgridsolar/
e-mail  offgridso...@sti.net
text 209 813 0060


What are the issues with tankless water heaters?  I have heard them
described as having "issues", but I haven't read anything that describes
what they are.  They are very popular where I live.  Any info? Thanks,
Chris


On 3/20/2018 1:07 PM, Dave Angelini Offgrid Solar wrote:

And a big maybe for Offgrid where we like multiple ways to
charge/heat/cool and make hot water. The default method is almost always
the most reliable. For a typical home a 50 gallon propane tank water
heater with a zinc change every 7 years is the norm.

An air to water heat pump, an open loop solar water panel or closed loop
if conditions warrant it are great secondary methods. To me heating
water
with electricity does not work because of winter and is a last thing to
add.A tankless and their issues are near the end of the list. Ground
source heat pumps are even lower to me with very nice prices on
extremely
efficient mini split air source pumps.

I always try and minimize generators but if you need them then it allows
one to have more options.

Dave Angelini Offgrid Solar
"we go where powerlines don't"
http://members.sti.net/offgridsolar/
e-mail  offgridso...@sti.net
text 209 813 0060


Maybe. I designed my own house to incorporate this. The most efficient
are
the vertical type, and at 6' the company advertised 20% recovery for
about
$1,300 if I remember correctly. This I'm sure is for a new copper pipe,
and
anyone who's ever taken apart a sewer pipe after a few years will know
all
pipes get a bacterial mat of a couple mm thick. I suspect this might be
a
pretty good insulator. At any rate there is a whole lot of copper
involved
and associated inherent environmental challenges. I can't help but
think
for the house design challenge to accommodate such a long perfectly
vertical pipe and expense another kW or more of solar would offset more
energy.

On Tue, Mar 20, 2018 at 9:50 AM, Drake
<drake.chamber...@redwoodalliance.org

wrote:
Daniel,

That sounds like an intriguing technology, much along the lines of an
air
to air heat exchanger. Thanks for the recommendation.  These systems
could
keep a lot of CO2 out of the atmosphere if widely used.

Drake


At 10:09 AM 3/19/2018, you wrote:

Content-Type: multipart/alternative;
   boundary="=_NextPart_000_0077_01D3BF6A.5EF88420"
Content-Language: en-us


Drake,

Have you or the client looked into the drainwater heat recovery units?
They make both a vertical and horizontal mounted version. They just
help
recover the waste heat from shower water going down the drain.

My understanding is that economically they are barely past the
breakeven
point when considering offsetting grid power. If using PV costs as the
benchmark, the economics would be better. If somehow this is off grid,
then
I’d say it’s a home run. (Hopefully though this is not
an
all-electric
off-grid building.)

The main benefit, as far as I understand it, is that you can get by
with
a
smaller unit, with a smaller heating element to perform the same task,
OR
you can get much longer showers from the same sized unit. Depending on
the
clients goals, this might be a useful tool to bring into the
situation.

Here are two brand names that I know of.
Vertical mount: renewability
Horizontal mount: ecodrain

I have not used these products, so I cannot endorse any of them, just
though it may be worth consideration.

With Regards,

Daniel Young,
NABCEP Certified PV Installation ProfessionalTM: Cert #031508-90

*From:* RE-wrenches <re-wrenches-boun...@lists.re-wrenches.org> *On
Behalf Of *Drake
*Sent:* Thursday, March 15, 2018 1:00 PM
*To:* RE-wrenches <re-wrenches@lists.re-wrenches.org>
*Subject:* Re: [RE-wrenches] Electric Water kWh/ person

This discussion has been a great help. The house is built and the
plumbing
is in, but could be modified. Wood stoves are not a likely solution. I
think we need a different water heating strategy.

Thank you all!

D

Re: [RE-wrenches] Electric Water kWh/ person

2018-03-20 Thread Dave Angelini Offgrid Solar 
Chris,

For Offgrid with minerals in the well water, getting the right flow, the
maintenance that is just not there with a tank heater. Tankless are great
for many but if you do add an open loop solar water panel, you need a
tank Just not worth it in places like the south west where there is
abundant sunshine. Offgrid in remote places where service is questionable
or unavailable, we go with the most reliable. I steer them that way for
other reasons also..

Dave Angelini Offgrid Solar
"we go where powerlines don't"
http://members.sti.net/offgridsolar/
e-mail  offgridso...@sti.net
text 209 813 0060

> What are the issues with tankless water heaters?  I have heard them
> described as having "issues", but I haven't read anything that describes
> what they are.  They are very popular where I live.  Any info? Thanks,
> Chris
>
>
> On 3/20/2018 1:07 PM, Dave Angelini Offgrid Solar wrote:
>> And a big maybe for Offgrid where we like multiple ways to
>> charge/heat/cool and make hot water. The default method is almost always
>> the most reliable. For a typical home a 50 gallon propane tank water
>> heater with a zinc change every 7 years is the norm.
>>
>> An air to water heat pump, an open loop solar water panel or closed loop
>> if conditions warrant it are great secondary methods. To me heating
>> water
>> with electricity does not work because of winter and is a last thing to
>> add.A tankless and their issues are near the end of the list. Ground
>> source heat pumps are even lower to me with very nice prices on
>> extremely
>> efficient mini split air source pumps.
>>
>> I always try and minimize generators but if you need them then it allows
>> one to have more options.
>>
>> Dave Angelini Offgrid Solar
>> "we go where powerlines don't"
>> http://members.sti.net/offgridsolar/
>> e-mail  offgridso...@sti.net
>> text 209 813 0060
>>
>>> Maybe. I designed my own house to incorporate this. The most efficient
>>> are
>>> the vertical type, and at 6' the company advertised 20% recovery for
>>> about
>>> $1,300 if I remember correctly. This I'm sure is for a new copper pipe,
>>> and
>>> anyone who's ever taken apart a sewer pipe after a few years will know
>>> all
>>> pipes get a bacterial mat of a couple mm thick. I suspect this might be
>>> a
>>> pretty good insulator. At any rate there is a whole lot of copper
>>> involved
>>> and associated inherent environmental challenges. I can't help but
>>> think
>>> for the house design challenge to accommodate such a long perfectly
>>> vertical pipe and expense another kW or more of solar would offset more
>>> energy.
>>>
>>> On Tue, Mar 20, 2018 at 9:50 AM, Drake
>>> <drake.chamber...@redwoodalliance.org
>>>> wrote:
>>>> Daniel,
>>>>
>>>> That sounds like an intriguing technology, much along the lines of an
>>>> air
>>>> to air heat exchanger. Thanks for the recommendation.  These systems
>>>> could
>>>> keep a lot of CO2 out of the atmosphere if widely used.
>>>>
>>>> Drake
>>>>
>>>>
>>>> At 10:09 AM 3/19/2018, you wrote:
>>>>
>>>> Content-Type: multipart/alternative;
>>>>   boundary="=_NextPart_000_0077_01D3BF6A.5EF88420"
>>>> Content-Language: en-us
>>>>
>>>>
>>>> Drake,
>>>>
>>>> Have you or the client looked into the drainwater heat recovery units?
>>>> They make both a vertical and horizontal mounted version. They just
>>>> help
>>>> recover the waste heat from shower water going down the drain.
>>>>
>>>> My understanding is that economically they are barely past the
>>>> breakeven
>>>> point when considering offsetting grid power. If using PV costs as the
>>>> benchmark, the economics would be better. If somehow this is off grid,
>>>> then
>>>> I’d say it’s a home run. (Hopefully though this is not
>>>> an
>>>> all-electric
>>>> off-grid building.)
>>>>
>>>> The main benefit, as far as I understand it, is that you can get by
>>>> with
>>>> a
>>>> smaller unit, with a smaller heating element to perform the same task,
>>>> OR
>>>> you can get much longer showers from the same sized unit. Depending on
>>>> the
>>>> clients go

Re: [RE-wrenches] Electric Water kWh/ person

2018-03-20 Thread cwarfel 
What are the issues with tankless water heaters?  I have heard them 
described as having "issues", but I haven't read anything that describes 
what they are.  They are very popular where I live.  Any info? Thanks, Chris



On 3/20/2018 1:07 PM, Dave Angelini Offgrid Solar wrote:

And a big maybe for Offgrid where we like multiple ways to
charge/heat/cool and make hot water. The default method is almost always
the most reliable. For a typical home a 50 gallon propane tank water
heater with a zinc change every 7 years is the norm.

An air to water heat pump, an open loop solar water panel or closed loop
if conditions warrant it are great secondary methods. To me heating water
with electricity does not work because of winter and is a last thing to
add.A tankless and their issues are near the end of the list. Ground
source heat pumps are even lower to me with very nice prices on extremely
efficient mini split air source pumps.

I always try and minimize generators but if you need them then it allows
one to have more options.

Dave Angelini Offgrid Solar
"we go where powerlines don't"
http://members.sti.net/offgridsolar/
e-mail  offgridso...@sti.net
text 209 813 0060


Maybe. I designed my own house to incorporate this. The most efficient are
the vertical type, and at 6' the company advertised 20% recovery for about
$1,300 if I remember correctly. This I'm sure is for a new copper pipe,
and
anyone who's ever taken apart a sewer pipe after a few years will know all
pipes get a bacterial mat of a couple mm thick. I suspect this might be a
pretty good insulator. At any rate there is a whole lot of copper involved
and associated inherent environmental challenges. I can't help but think
for the house design challenge to accommodate such a long perfectly
vertical pipe and expense another kW or more of solar would offset more
energy.

On Tue, Mar 20, 2018 at 9:50 AM, Drake
<drake.chamber...@redwoodalliance.org

wrote:
Daniel,

That sounds like an intriguing technology, much along the lines of an
air
to air heat exchanger. Thanks for the recommendation.  These systems
could
keep a lot of CO2 out of the atmosphere if widely used.

Drake


At 10:09 AM 3/19/2018, you wrote:

Content-Type: multipart/alternative;
  boundary="=_NextPart_000_0077_01D3BF6A.5EF88420"
Content-Language: en-us


Drake,

Have you or the client looked into the drainwater heat recovery units?
They make both a vertical and horizontal mounted version. They just help
recover the waste heat from shower water going down the drain.

My understanding is that economically they are barely past the breakeven
point when considering offsetting grid power. If using PV costs as the
benchmark, the economics would be better. If somehow this is off grid,
then
I’d say it’s a home run. (Hopefully though this is not an
all-electric
off-grid building.)

The main benefit, as far as I understand it, is that you can get by with
a
smaller unit, with a smaller heating element to perform the same task,
OR
you can get much longer showers from the same sized unit. Depending on
the
clients goals, this might be a useful tool to bring into the situation.

Here are two brand names that I know of.
Vertical mount: renewability
Horizontal mount: ecodrain

I have not used these products, so I cannot endorse any of them, just
though it may be worth consideration.

With Regards,

Daniel Young,
NABCEP Certified PV Installation ProfessionalTM: Cert #031508-90

*From:* RE-wrenches <re-wrenches-boun...@lists.re-wrenches.org> *On
Behalf Of *Drake
*Sent:* Thursday, March 15, 2018 1:00 PM
*To:* RE-wrenches <re-wrenches@lists.re-wrenches.org>
*Subject:* Re: [RE-wrenches] Electric Water kWh/ person

This discussion has been a great help. The house is built and the
plumbing
is in, but could be modified. Wood stoves are not a likely solution. I
think we need a different water heating strategy.

Thank you all!

Drake



At 09:21 AM 3/15/2018, you wrote:

Content-Type: multipart/alternative;
  boundary="EE4E9806B711DEF636076840"
Content-Language: en-US

This is what I came up with:

The calculation is Q = mcp delta T

Water Temp out =Â  120

Water Temp in = ground source Temperature @ 50F?

delta T = 70F

m =  mass flow rate.  ASHRAE is the source for this. 20gals per
person
per day = 20 gallons x 8.34 lbs/gallon =Â  167lbs/day/person

cp =Â  1 BTU/lb-degree F

Q = 167 x 1 x 70 = 11,676 BTU/day/person

Divide this by the efficiency of the water heating system (I'll assume =
.86)Â  =11,676/.86 = 13, 577 BTU/person/day

convert to kWh if necessarym 13,577/3412 = ~4 kWh/person/day, 120
kWh/month

I checked this against one month and it seems reasonable.

Website assuming ~3.5 family size comes up with @ 400kWh per month. They
approached it another way with assuming run times.

https://www.google.com/search?safe=active=hp=
Z3KqWvXiNsGb5wKJ2Kf4DA=electric+water+heater+use+annual+consu

Re: [RE-wrenches] Electric Water kWh/ person

2018-03-20 Thread Dave Angelini Offgrid Solar 
And a big maybe for Offgrid where we like multiple ways to
charge/heat/cool and make hot water. The default method is almost always
the most reliable. For a typical home a 50 gallon propane tank water
heater with a zinc change every 7 years is the norm.

An air to water heat pump, an open loop solar water panel or closed loop
if conditions warrant it are great secondary methods. To me heating water
with electricity does not work because of winter and is a last thing to
add.A tankless and their issues are near the end of the list. Ground
source heat pumps are even lower to me with very nice prices on extremely
efficient mini split air source pumps.

I always try and minimize generators but if you need them then it allows
one to have more options.

Dave Angelini Offgrid Solar
"we go where powerlines don't"
http://members.sti.net/offgridsolar/
e-mail  offgridso...@sti.net
text 209 813 0060

> Maybe. I designed my own house to incorporate this. The most efficient are
> the vertical type, and at 6' the company advertised 20% recovery for about
> $1,300 if I remember correctly. This I'm sure is for a new copper pipe,
> and
> anyone who's ever taken apart a sewer pipe after a few years will know all
> pipes get a bacterial mat of a couple mm thick. I suspect this might be a
> pretty good insulator. At any rate there is a whole lot of copper involved
> and associated inherent environmental challenges. I can't help but think
> for the house design challenge to accommodate such a long perfectly
> vertical pipe and expense another kW or more of solar would offset more
> energy.
>
> On Tue, Mar 20, 2018 at 9:50 AM, Drake
> <drake.chamber...@redwoodalliance.org
>> wrote:
>
>> Daniel,
>>
>> That sounds like an intriguing technology, much along the lines of an
>> air
>> to air heat exchanger. Thanks for the recommendation.  These systems
>> could
>> keep a lot of CO2 out of the atmosphere if widely used.
>>
>> Drake
>>
>>
>> At 10:09 AM 3/19/2018, you wrote:
>>
>> Content-Type: multipart/alternative;
>>  boundary="=_NextPart_000_0077_01D3BF6A.5EF88420"
>> Content-Language: en-us
>>
>>
>> Drake,
>>
>> Have you or the client looked into the drainwater heat recovery units?
>> They make both a vertical and horizontal mounted version. They just help
>> recover the waste heat from shower water going down the drain.
>>
>> My understanding is that economically they are barely past the breakeven
>> point when considering offsetting grid power. If using PV costs as the
>> benchmark, the economics would be better. If somehow this is off grid,
>> then
>> I’d say it’s a home run. (Hopefully though this is not an
>> all-electric
>> off-grid building.)
>>
>> The main benefit, as far as I understand it, is that you can get by with
>> a
>> smaller unit, with a smaller heating element to perform the same task,
>> OR
>> you can get much longer showers from the same sized unit. Depending on
>> the
>> clients goals, this might be a useful tool to bring into the situation.
>>
>> Here are two brand names that I know of.
>> Vertical mount: renewability
>> Horizontal mount: ecodrain
>>
>> I have not used these products, so I cannot endorse any of them, just
>> though it may be worth consideration.
>>
>> With Regards,
>>
>> Daniel Young,
>> NABCEP Certified PV Installation ProfessionalTM: Cert #031508-90
>>
>> *From:* RE-wrenches <re-wrenches-boun...@lists.re-wrenches.org> *On
>> Behalf Of *Drake
>> *Sent:* Thursday, March 15, 2018 1:00 PM
>> *To:* RE-wrenches <re-wrenches@lists.re-wrenches.org>
>> *Subject:* Re: [RE-wrenches] Electric Water kWh/ person
>>
>> This discussion has been a great help. The house is built and the
>> plumbing
>> is in, but could be modified. Wood stoves are not a likely solution. I
>> think we need a different water heating strategy.
>>
>> Thank you all!
>>
>> Drake
>>
>>
>>
>> At 09:21 AM 3/15/2018, you wrote:
>>
>> Content-Type: multipart/alternative;
>>  boundary="EE4E9806B711DEF636076840"
>> Content-Language: en-US
>>
>> This is what I came up with:
>>
>> The calculation is Q = mcp delta T
>>
>> Water Temp out =Â  120
>>
>> Water Temp in = ground source Temperature @ 50F?
>>
>> delta T = 70F
>>
>> m =  mass flow rate.  ASHRAE is the source for this. 20gals per
>> person
>> per day = 20 gallons x 8.34 lbs/gallon =Â  167lbs/day/person
>>
>> cp =Â  1 BTU/lb

Re: [RE-wrenches] Electric Water kWh/ person

2018-03-20 Thread Barton Churchill 
Maybe. I designed my own house to incorporate this. The most efficient are
the vertical type, and at 6' the company advertised 20% recovery for about
$1,300 if I remember correctly. This I'm sure is for a new copper pipe, and
anyone who's ever taken apart a sewer pipe after a few years will know all
pipes get a bacterial mat of a couple mm thick. I suspect this might be a
pretty good insulator. At any rate there is a whole lot of copper involved
and associated inherent environmental challenges. I can't help but think
for the house design challenge to accommodate such a long perfectly
vertical pipe and expense another kW or more of solar would offset more
energy.

On Tue, Mar 20, 2018 at 9:50 AM, Drake <drake.chamber...@redwoodalliance.org
> wrote:

> Daniel,
>
> That sounds like an intriguing technology, much along the lines of an air
> to air heat exchanger. Thanks for the recommendation.  These systems could
> keep a lot of CO2 out of the atmosphere if widely used.
>
> Drake
>
>
> At 10:09 AM 3/19/2018, you wrote:
>
> Content-Type: multipart/alternative;
>  boundary="=_NextPart_000_0077_01D3BF6A.5EF88420"
> Content-Language: en-us
>
>
> Drake,
>
> Have you or the client looked into the drainwater heat recovery units?
> They make both a vertical and horizontal mounted version. They just help
> recover the waste heat from shower water going down the drain.
>
> My understanding is that economically they are barely past the breakeven
> point when considering offsetting grid power. If using PV costs as the
> benchmark, the economics would be better. If somehow this is off grid, then
> I’d say it’s a home run. (Hopefully though this is not an all-electric
> off-grid building.)
>
> The main benefit, as far as I understand it, is that you can get by with a
> smaller unit, with a smaller heating element to perform the same task, OR
> you can get much longer showers from the same sized unit. Depending on the
> clients goals, this might be a useful tool to bring into the situation.
>
> Here are two brand names that I know of.
> Vertical mount: renewability
> Horizontal mount: ecodrain
>
> I have not used these products, so I cannot endorse any of them, just
> though it may be worth consideration.
>
> With Regards,
>
> Daniel Young,
> NABCEP Certified PV Installation ProfessionalTM: Cert #031508-90
>
> *From:* RE-wrenches <re-wrenches-boun...@lists.re-wrenches.org> *On
> Behalf Of *Drake
> *Sent:* Thursday, March 15, 2018 1:00 PM
> *To:* RE-wrenches <re-wrenches@lists.re-wrenches.org>
> *Subject:* Re: [RE-wrenches] Electric Water kWh/ person
>
> This discussion has been a great help. The house is built and the plumbing
> is in, but could be modified. Wood stoves are not a likely solution. I
> think we need a different water heating strategy.
>
> Thank you all!
>
> Drake
>
>
>
> At 09:21 AM 3/15/2018, you wrote:
>
> Content-Type: multipart/alternative;
>  boundary="EE4E9806B711DEF636076840"
> Content-Language: en-US
>
> This is what I came up with:
>
> The calculation is Q = mcp delta T
>
> Water Temp out =Â  120
>
> Water Temp in = ground source Temperature @ 50F?
>
> delta T = 70F
>
> m =  mass flow rate.  ASHRAE is the source for this. 20gals per person
> per day = 20 gallons x 8.34 lbs/gallon =Â  167lbs/day/person
>
> cp =Â  1 BTU/lb-degree F
>
> Q = 167 x 1 x 70 = 11,676 BTU/day/person
>
> Divide this by the efficiency of the water heating system (I'll assume =
> .86)Â  =11,676/.86 = 13, 577 BTU/person/day
>
> convert to kWh if necessarym 13,577/3412 = ~4 kWh/person/day, 120 kWh/month
>
> I checked this against one month and it seems reasonable.
>
> Website assuming ~3.5 family size comes up with @ 400kWh per month. They
> approached it another way with assuming run times.
>
> https://www.google.com/search?safe=active=hp=
> Z3KqWvXiNsGb5wKJ2Kf4DA=electric+water+heater+use+annual+consumption=
> electric+water+heater+use+annually_l=psy-ab.1.2.
> 33i22i29i30k1l3.279.9222.0.12475.35.19.0.7.7.0.451.2360.
> 0j6j4j0j1.11.00...1c.1.64.psy-ab..18.16.1952.0..
> 0j0i67k1j0i131k1j0i22i30k1.0.CiU8wYZigpI
>
>
> Chris
>
>
>
>
> On 3/15/2018 8:09 AM, Mike Kocsmiersky wrote:
>
> Barton makes a good point with regards to the incoming ground water
> temperature and the amount of heat required to bring it up to shower temp.
> Â My recollection is that ASHRAE states 20gal/person/day for the first 2
> people, then 15gpd or 12gpd thereafter.  However those rates vary wildly
> with consumers, from those that never bathe to the high schooler that needs
> 3 showers a day.  In the northeast water heating can be up to 19%

Re: [RE-wrenches] Electric Water kWh/ person

2018-03-20 Thread Drake 

Daniel,

That sounds like an intriguing technology, much 
along the lines of an air to air heat exchanger. 
Thanks for the recommendation.  These systems 
could keep a lot of CO2 out of the atmosphere if widely used.


Drake


At 10:09 AM 3/19/2018, you wrote:

Content-Type: multipart/alternative;
boundary="=_NextPart_000_0077_01D3BF6A.5EF88420"
Content-Language: en-us

Drake,

Have you or the client looked into the 
drainwater heat recovery units? They make both a 
vertical and horizontal mounted version. They 
just help recover the waste heat from shower water going down the drain.


My understanding is that economically they are 
barely past the breakeven point when considering 
offsetting grid power. If using PV costs as the 
benchmark, the economics would be better. If 
somehow this is off grid, then I’d say it’s a 
home run. (Hopefully though this is not an all-electric off-grid building.)


The main benefit, as far as I understand it, is 
that you can get by with a smaller unit, with a 
smaller heating element to perform the same 
task, OR you can get much longer showers from 
the same sized unit. Depending on the clients 
goals, this might be a useful tool to bring into the situation.


Here are two brand names that I know of.
Vertical mount: renewability
Horizontal mount: ecodrain

I have not used these products, so I cannot 
endorse any of them, just though it may be worth consideration.


With Regards,

Daniel Young,
NABCEP Certified PV Installation ProfessionalTM: Cert #031508-90

From: RE-wrenches 
<re-wrenches-boun...@lists.re-wrenches.org> On Behalf Of Drake

Sent: Thursday, March 15, 2018 1:00 PM
To: RE-wrenches <re-wrenches@lists.re-wrenches.org>
Subject: Re: [RE-wrenches] Electric Water kWh/ person

This discussion has been a great help. The house 
is built and the plumbing is in, but could be 
modified. Wood stoves are not a likely solution. 
I think we need a different water heating strategy.


Thank you all!

Drake



At 09:21 AM 3/15/2018, you wrote:

Content-Type: multipart/alternative;
 boundary="EE4E9806B711DEF636076840"
Content-Language: en-US

This is what I came up with:

The calculation is Q = mcp delta T

Water Temp out =Â  120

Water Temp in = ground source Temperature @ 50F?

delta T = 70F

m =  mass flow rate.  ASHRAE is the source for 
this. 20gals per person per day = 20 gallons x 
8.34 lbs/gallon =Â  167lbs/day/person


cp =Â  1 BTU/lb-degree F

Q = 167 x 1 x 70 = 11,676 BTU/day/person

Divide this by the efficiency of the water 
heating system (I'll assume = .86)Â  =11,676/.86 = 13, 577 BTU/person/day


convert to kWh if necessarym 13,577/3412 = ~4 kWh/person/day, 120 kWh/month

I checked this against one month and it seems reasonable.

Website assuming ~3.5 family size comes up with 
@ 400kWh per month. They approached it another way with assuming run times.


<https://www.google.com/search?safe=active=hp=Z3KqWvXiNsGb5wKJ2Kf4DA=electric+water+heater+use+annual+consumption=electric+water+heater+use+annually_l=psy-ab.1.2.33i22i29i30k1l3.279.9222.0.12475.35.19.0.7.7.0.451.2360.0j6j4j0j1.11.00...1c.1.64.psy-ab..18.16.1952.0..0j0i67k1j0i131k1j0i22i30k1.0.CiU8wYZigpI>https://www.google.com/search?safe=active=hp=Z3KqWvXiNsGb5wKJ2Kf4DA=electric+water+heater+use+annual+consumption=electric+water+heater+use+annually_l=psy-ab.1.2.33i22i29i30k1l3.279.9222.0.12475.35.19.0.7.7.0.451.2360.0j6j4j0j1.11.00...1c.1.64.psy-ab..18.16.1952.0..0j0i67k1j0i131k1j0i22i30k1.0.CiU8wYZigpI 




Chris




On 3/15/2018 8:09 AM, Mike Kocsmiersky wrote:

Barton makes a good point with regards to the 
incoming ground water temperature and the amount 
of heat required to bring it up to shower temp. 
 My recollection is that ASHRAE states 
20gal/person/day for the first 2 people, then 
15gpd or 12gpd thereafter.  However those rates 
vary wildly with consumers, from those that 
never bathe to the high schooler that needs 3 
showers a day.  In the northeast water heating 
can be up to 19% of the total household energy 
load for the year.  Also, I would recommend the 
air source heat pump water heaters if you have 
significant humidity or an on demand 
unit.  Water tanks are typically under 
insulated and can lose 2kWh/day in standby losses.

Â
Mike Kocsmiersky
Principal
Spirit Solar Inc.
(413) 734-1456
Â
Â
Â
From: Barton Churchill 
[<mailto:bar...@solarips.com>mailto:bar...@solarips.com]

Sent: Wednesday, March 14, 2018 7:31 PM
To: RE-wrenches
Subject: Re: [RE-wrenches] Electric Water kWh/ person
Â
You first need to know your ground temperature. 
Then figure a delta to 100 or so degrees. Most 
but not all showerheads flow 2.5gpm and showers 
are typically 10 minutes. You can then find a 
calculator online to calculate how many Btus are 
required to raise water temp for your delta per 
gallon. Convert to kWh, add some contingency and you should be good.Â


On Wednesday, March 14, 2018, 
<<mailto:dr

Re: [RE-wrenches] Electric Water kWh/ person

2018-03-19 Thread cwarfel 
I had thought of this a long time ago for an island project, but the 
cost of plumbing cold inlet water past the heat exchanger was too high. 
I think this can work at time of construction or easy renovation. We do 
this for large thermal dump loads for fabric mills for example.



On 3/19/2018 10:09 AM, Daniel Young wrote:


Drake,

Have you or the client looked into the drainwater heat recovery units? 
They make both a vertical and horizontal mounted version. They just 
help recover the waste heat from shower water going down the drain.


My understanding is that economically they are barely past the 
breakeven point when considering offsetting grid power. If using PV 
costs as the benchmark, the economics would be better. If somehow this 
is off grid, then I’d say it’s a home run. (Hopefully though this is 
not an all-electric off-grid building.)


The main benefit, as far as I understand it, is that you can get by 
with a smaller unit, with a smaller heating element to perform the 
same task, OR you can get much longer showers from the same sized 
unit. Depending on the clients goals, this might be a useful tool to 
bring into the situation.


Here are two brand names that I know of.

Vertical mount: renewability

Horizontal mount: ecodrain

I have not used these products, so I cannot endorse any of them, just 
though it may be worth consideration.


With Regards,

Daniel Young,

NABCEP Certified PV Installation Professional^TM : Cert #031508-90

*From:* RE-wrenches <re-wrenches-boun...@lists.re-wrenches.org> *On 
Behalf Of *Drake

*Sent:* Thursday, March 15, 2018 1:00 PM
*To:* RE-wrenches <re-wrenches@lists.re-wrenches.org>
*Subject:* Re: [RE-wrenches] Electric Water kWh/ person

This discussion has been a great help. The house is built and the 
plumbing is in, but could be modified. Wood stoves are not a likely 
solution. I think we need a different water heating strategy.


Thank you all!

Drake



At 09:21 AM 3/15/2018, you wrote:

Content-Type: multipart/alternative;
 boundary="EE4E9806B711DEF636076840"
Content-Language: en-US

This is what I came up with:

The calculation is Q = mcp delta T

Water Temp out =  120

Water Temp in = ground source Temperature @ 50F?

delta T = 70F

m =  mass flow rate.  ASHRAE is the source for this. 20gals per
person per day = 20 gallons x 8.34 lbs/gallon =  167lbs/day/person

cp =  1 BTU/lb-degree F

Q = 167 x 1 x 70 = 11,676 BTU/day/person

Divide this by the efficiency of the water heating system (I'll
assume = .86)  =11,676/.86 = 13, 577 BTU/person/day

convert to kWh if necessarym 13,577/3412 = ~4 kWh/person/day, 120
kWh/month

I checked this against one month and it seems reasonable.

Website assuming ~3.5 family size comes up with @ 400kWh per
month. They approached it another way with assuming run times.


https://www.google.com/search?safe=active=hp=Z3KqWvXiNsGb5wKJ2Kf4DA=electric+water+heater+use+annual+consumption=electric+water+heater+use+annually_l=psy-ab.1.2.33i22i29i30k1l3.279.9222.0.12475.35.19.0.7.7.0.451.2360.0j6j4j0j1.11.00...1c.1.64.psy-ab..18.16.1952.0..0j0i67k1j0i131k1j0i22i30k1.0.CiU8wYZigpI



Chris




On 3/15/2018 8:09 AM, Mike Kocsmiersky wrote:

Barton makes a good point with regards to the incoming ground
water temperature and the amount of heat required to bring it
up to shower temp. Â My recollection is that ASHRAE states
20gal/person/day for the first 2 people, then 15gpd or 12gpd
thereafter.  However those rates vary wildly with consumers,
from those that never bathe to the high schooler that needs 3
showers a day.  In the northeast water heating can be up to
19% of the total household energy load for the year.  Also, I
would recommend the air source heat pump water heaters if you
have significant humidity or an on demand unit.  Water tanks
are typically under insulated and can lose 2kWh/day in standby
losses.
Â
Mike Kocsmiersky
Principal
Spirit Solar Inc.
(413) 734-1456
Â
Â
Â
*From:* Barton Churchill [mailto:bar...@solarips.com]
*Sent:* Wednesday, March 14, 2018 7:31 PM
*To:* RE-wrenches
        *Subject:* Re: [RE-wrenches] Electric Water kWh/ person
Â
You first need to know your ground temperature. Then figure a
delta to 100 or so degrees. Most but not all showerheads flow
2.5gpm and showers are typically 10 minutes. You can then find
a calculator online to calculate how many Btus are required to
raise water temp for your delta per gallon. Convert to kWh,
add some contingency and you should be good.Â

On Wednesday, March 14, 2018,
<drake.chamber...@redwoodalliance.org
<mailto:drake.chamber...@redwoodalliance.org>

Re: [RE-wrenches] Electric Water kWh/ person

2018-03-19 Thread Daniel Young 
Drake,

 

Have you or the client looked into the drainwater heat recovery units? They
make both a vertical and horizontal mounted version. They just help recover
the waste heat from shower water going down the drain.

 

My understanding is that economically they are barely past the breakeven
point when considering offsetting grid power. If using PV costs as the
benchmark, the economics would be better. If somehow this is off grid, then
I’d say it’s a home run. (Hopefully though this is not an all-electric
off-grid building.)

 

The main benefit, as far as I understand it, is that you can get by with a
smaller unit, with a smaller heating element to perform the same task, OR
you can get much longer showers from the same sized unit. Depending on the
clients goals, this might be a useful tool to bring into the situation.

 

Here are two brand names that I know of.

Vertical mount: renewability

Horizontal mount: ecodrain

 

I have not used these products, so I cannot endorse any of them, just though
it may be worth consideration.

 

With Regards,

 

Daniel Young, 

NABCEP Certified PV Installation ProfessionalTM: Cert #031508-90

 

From: RE-wrenches <re-wrenches-boun...@lists.re-wrenches.org> On Behalf Of
Drake
Sent: Thursday, March 15, 2018 1:00 PM
To: RE-wrenches <re-wrenches@lists.re-wrenches.org>
Subject: Re: [RE-wrenches] Electric Water kWh/ person

 

This discussion has been a great help. The house is built and the plumbing
is in, but could be modified. Wood stoves are not a likely solution. I think
we need a different water heating strategy.

Thank you all!

Drake 



At 09:21 AM 3/15/2018, you wrote:



Content-Type: multipart/alternative;
 boundary="EE4E9806B711DEF636076840"
Content-Language: en-US

This is what I came up with:

The calculation is Q = mcp delta T

Water Temp out =Â  120

Water Temp in = ground source Temperature @ 50F?

delta T = 70F

m =  mass flow rate.  ASHRAE is the source for this. 20gals per person per
day = 20 gallons x 8.34 lbs/gallon =Â  167lbs/day/person

cp =Â  1 BTU/lb-degree F

Q = 167 x 1 x 70 = 11,676 BTU/day/person

Divide this by the efficiency of the water heating system (I'll assume =
.86)Â  =11,676/.86 = 13, 577 BTU/person/day

convert to kWh if necessarym 13,577/3412 = ~4 kWh/person/day, 120 kWh/month

I checked this against one month and it seems reasonable. 

Website assuming ~3.5 family size comes up with @ 400kWh per month. They
approached it another way with assuming run times.

https://www.google.com/search?safe=active
<https://www.google.com/search?safe=active=hp=Z3KqWvXiNsGb5wKJ2Kf4
DA=electric+water+heater+use+annual+consumption=electric+water+heater+u
se+annually_l=psy-ab.1.2.33i22i29i30k1l3.279.9222.0.12475.35.19.0.7.7.0.4
51.2360.0j6j4j0j1.11.00...1c.1.64.psy-ab..18.16.1952.0..0j0i67k1j0i131k1
j0i22i30k1.0.CiU8wYZigpI>
=hp=Z3KqWvXiNsGb5wKJ2Kf4DA=electric+water+heater+use+annual+cons
umption=electric+water+heater+use+annually_l=psy-ab.1.2.33i22i29i30k1l
3.279.9222.0.12475.35.19.0.7.7.0.451.2360.0j6j4j0j1.11.00...1c.1.64.psy-
ab..18.16.1952.0..0j0i67k1j0i131k1j0i22i30k1.0.CiU8wYZigpI 


Chris




On 3/15/2018 8:09 AM, Mike Kocsmiersky wrote:



Barton makes a good point with regards to the incoming ground water
temperature and the amount of heat required to bring it up to shower temp. Â
My recollection is that ASHRAE states 20gal/person/day for the first 2
people, then 15gpd or 12gpd thereafter.  However those rates vary wildly
with consumers, from those that never bathe to the high schooler that needs
3 showers a day.  In the northeast water heating can be up to 19% of the
total household energy load for the year.  Also, I would recommend the air
source heat pump water heaters if you have significant humidity or an on
demand unit.  Water tanks are typically under insulated and can lose
2kWh/day in standby losses.
 
Mike Kocsmiersky
Principal
Spirit Solar Inc.
(413) 734-1456
 
 
 
From: Barton Churchill [mailto:bar...@solarips.com] 
Sent: Wednesday, March 14, 2018 7:31 PM
To: RE-wrenches
Subject: Re: [RE-wrenches] Electric Water kWh/ person
 
You first need to know your ground temperature. Then figure a delta to 100
or so degrees. Most but not all showerheads flow 2.5gpm and showers are
typically 10 minutes. You can then find a calculator online to calculate how
many Btus are required to raise water temp for your delta per gallon.
Convert to kWh, add some contingency and you should be good. 

On Wednesday, March 14, 2018, < drake.chamber...@redwoodalliance.org
<mailto:drake.chamber...@redwoodalliance.org> > wrote:
Hello Wrenches,

Is there a good way to estimate the power that will be consumed for electric
water per person per day? We are estimating the amount of power that will be
used by an all electric duplex, and the water heater amount seems high. The
current model we have claims 3493 kWh/ year per 26 gallon tank will be
consumed. With the two units, that would

Re: [RE-wrenches] Electric Water kWh/ person

2018-03-15 Thread Darryl Thayer 
I had 3 customers that were my data source. unfortunately, I had trouble
monitoring the thermal systems and they got tired of me coming over daily
to see the runtimes ect one gave up on solar thermal when a leak occurred,
The other two I stopped monitoring because of expenses in the monitoring of
the solar thermal.

On Thu, Mar 15, 2018 at 12:35 PM, cwarfel <cwar...@entech-engineering.com>
wrote:

> That would be a good analysis to share. I can see how it could be possible
> with lower module costs, but I haven't seen any studies on this comparison.
> Chris
>
> On 3/15/2018 1:17 PM, Darryl Thayer wrote:
>
> When I did my study of solar water heating I found that PV water heating
> gave more hot water at a lower cost than solar thermal.  the Heatpump water
> heater was the big winner.
>
> On Thu, Mar 15, 2018 at 12:00 PM, Drake <drake.chamberlin@
> redwoodalliance.org> wrote:
>
>> This discussion has been a great help. The house is built and the
>> plumbing is in, but could be modified. Wood stoves are not a likely
>> solution. I think we need a different water heating strategy.
>>
>> Thank you all!
>>
>> Drake
>>
>>
>>
>> At 09:21 AM 3/15/2018, you wrote:
>>
>> Content-Type: multipart/alternative;
>>  boundary="EE4E9806B711DEF636076840"
>> Content-Language: en-US
>>
>> This is what I came up with:
>>
>> The calculation is Q = mcp delta T
>>
>> Water Temp out =Â  120
>>
>> Water Temp in = ground source Temperature @ 50F?
>>
>> delta T = 70F
>>
>> m =  mass flow rate.  ASHRAE is the source for this. 20gals per person
>> per day = 20 gallons x 8.34 lbs/gallon =Â  167lbs/day/person
>>
>> cp =Â  1 BTU/lb-degree F
>>
>> Q = 167 x 1 x 70 = 11,676 BTU/day/person
>>
>> Divide this by the efficiency of the water heating system (I'll assume =
>> .86)Â  =11,676/.86 = 13, 577 BTU/person/day
>>
>> convert to kWh if necessarym 13,577/3412 = ~4 kWh/person/day, 120
>> kWh/month
>>
>> I checked this against one month and it seems reasonable.
>>
>> Website assuming ~3.5 family size comes up with @ 400kWh per month. They
>> approached it another way with assuming run times.
>>
>> https://www.google.com/search?safe=active=hp=Z3KqW
>> vXiNsGb5wKJ2Kf4DA=electric+water+heater+use+annual+
>> consumption=electric+water+heater+use+annually_l=psy-
>> ab.1.2.33i22i29i30k1l3.279.9222.0.12475.35.19.0.7.7.0.
>> 451.2360.0j6j4j0j1.11.00...1c.1.64.psy-ab..18.16.1952.0.
>> .0j0i67k1j0i131k1j0i22i30k1.0.CiU8wYZigpI
>>
>>
>> Chris
>>
>>
>>
>>
>> On 3/15/2018 8:09 AM, Mike Kocsmiersky wrote:
>>
>> Barton makes a good point with regards to the incoming ground water
>> temperature and the amount of heat required to bring it up to shower temp.
>> Â My recollection is that ASHRAE states 20gal/person/day for the first 2
>> people, then 15gpd or 12gpd thereafter.  However those rates vary wildly
>> with consumers, from those that never bathe to the high schooler that needs
>> 3 showers a day.  In the northeast water heating can be up to 19% of the
>> total household energy load for the year.  Also, I would recommend the air
>> source heat pump water heaters if you have significant humidity or an on
>> demand unit.  Water tanks are typically under insulated and can lose
>> 2kWh/day in standby losses.
>> Â
>> Mike Kocsmiersky
>> Principal
>> Spirit Solar Inc.
>> (413) 734-1456
>> Â
>> Â
>> Â
>> *From:* Barton Churchill [mailto:bar...@solarips.com
>> <bar...@solarips.com>]
>> *Sent:* Wednesday, March 14, 2018 7:31 PM
>> *To:* RE-wrenches
>> *Subject:* Re: [RE-wrenches] Electric Water kWh/ person
>> Â
>> You first need to know your ground temperature. Then figure a delta to
>> 100 or so degrees. Most but not all showerheads flow 2.5gpm and showers are
>> typically 10 minutes. You can then find a calculator online to calculate
>> how many Btus are required to raise water temp for your delta per gallon.
>> Convert to kWh, add some contingency and you should be good.Â
>>
>> On Wednesday, March 14, 2018, < drake.chamber...@redwoodalliance.org>
>> wrote:
>> Hello Wrenches,
>>
>> Is there a good way to estimate the power that will be consumed for
>> electric water per person per day? We are estimating the amount of power
>> that will be used by an all electric duplex, and the water heater amount
>> seems high. The current model we have claims 3493 kWh/ year per 26 gallon
>> tank will be c

Re: [RE-wrenches] Electric Water kWh/ person

2018-03-15 Thread cwarfel 
That would be a good analysis to share. I can see how it could be 
possible with lower module costs, but I haven't seen any studies on this 
comparison. Chris



On 3/15/2018 1:17 PM, Darryl Thayer wrote:
When I did my study of solar water heating I found that PV water 
heating gave more hot water at a lower cost than solar thermal.  the 
Heatpump water heater was the big winner.


On Thu, Mar 15, 2018 at 12:00 PM, Drake 
<drake.chamber...@redwoodalliance.org 
<mailto:drake.chamber...@redwoodalliance.org>> wrote:


This discussion has been a great help. The house is built and the
plumbing is in, but could be modified. Wood stoves are not a
likely solution. I think we need a different water heating strategy.

Thank you all!

Drake



At 09:21 AM 3/15/2018, you wrote:

Content-Type: multipart/alternative;
 boundary="EE4E9806B711DEF636076840"
Content-Language: en-US

This is what I came up with:

The calculation is Q = mcp delta T

Water Temp out =  120

Water Temp in = ground source Temperature @ 50F?

delta T = 70F

m =  mass flow rate. ASHRAE is the source for this. 20gals per
person per day = 20 gallons x 8.34 lbs/gallon =  167lbs/day/person

cp =  1 BTU/lb-degree F

Q = 167 x 1 x 70 = 11,676 BTU/day/person

Divide this by the efficiency of the water heating system (I'll
assume = .86)  =11,676/.86 = 13, 577 BTU/person/day

convert to kWh if necessarym 13,577/3412 = ~4 kWh/person/day, 120
kWh/month

I checked this against one month and it seems reasonable.

Website assuming ~3.5 family size comes up with @ 400kWh per
month. They approached it another way with assuming run times.


https://www.google.com/search?safe=active=hp=Z3KqWvXiNsGb5wKJ2Kf4DA=electric+water+heater+use+annual+consumption=electric+water+heater+use+annually_l=psy-ab.1.2.33i22i29i30k1l3.279.9222.0.12475.35.19.0.7.7.0.451.2360.0j6j4j0j1.11.00...1c.1.64.psy-ab..18.16.1952.0..0j0i67k1j0i131k1j0i22i30k1.0.CiU8wYZigpI

<https://www.google.com/search?safe=active=hp=Z3KqWvXiNsGb5wKJ2Kf4DA=electric+water+heater+use+annual+consumption=electric+water+heater+use+annually_l=psy-ab.1.2.33i22i29i30k1l3.279.9222.0.12475.35.19.0.7.7.0.451.2360.0j6j4j0j1.11.00...1c.1.64.psy-ab..18.16.1952.0..0j0i67k1j0i131k1j0i22i30k1.0.CiU8wYZigpI>



Chris




On 3/15/2018 8:09 AM, Mike Kocsmiersky wrote:

Barton makes a good point with regards to the incoming ground
water temperature and the amount of heat required to bring it up
to shower temp. Â My recollection is that ASHRAE states
20gal/person/day for the first 2 people, then 15gpd or 12gpd
thereafter.  However those rates vary wildly with consumers,
from those that never bathe to the high schooler that needs 3
showers a day.  In the northeast water heating can be up to 19%
of the total household energy load for the year.  Also, I would
recommend the air source heat pump water heaters if you have
significant humidity or an on demand unit.  Water tanks are
typically under insulated and can lose 2kWh/day in standby losses.
Â
Mike Kocsmiersky
Principal
Spirit Solar Inc.
(413) 734-1456 <tel:%28413%29%20734-1456>
Â
Â
Â
*From:* Barton Churchill [mailto:bar...@solarips.com]
*Sent:* Wednesday, March 14, 2018 7:31 PM
*To:* RE-wrenches
*Subject:* Re: [RE-wrenches] Electric Water kWh/ person
Â
You first need to know your ground temperature. Then figure a
delta to 100 or so degrees. Most but not all showerheads flow
2.5gpm and showers are typically 10 minutes. You can then find a
calculator online to calculate how many Btus are required to
raise water temp for your delta per gallon. Convert to kWh, add
some contingency and you should be good.Â

On Wednesday, March 14, 2018,
<drake.chamber...@redwoodalliance.org
<mailto:drake.chamber...@redwoodalliance.org>> wrote:
Hello Wrenches,

Is there a good way to estimate the power that will be consumed
for electric water per person per day? We are estimating the
amount of power that will be used by an all electric duplex, and
the water heater amount seems high. The current model we have
claims 3493 kWh/ year per 26 gallon tank will be consumed. With
the two units, that would add up to 6986 kWh / year for hot
water, pushing the system size to humongous for a 1300 ft sq
building.

Does that seem high? There will be a maximum of 2 people per unit.

The owner is considering going to 115 V units with a 15 gallon
tanks. I think the smaller tank would help, but it would seem
that the amount of hot water consumed would be the main issue.

How can we get a good estimate for a per person energy usage for
electric hot water? Any other suggestions are welcome.

Thank you,

Drake



-- 
--Â

Barton C

Re: [RE-wrenches] Electric Water kWh/ person

2018-03-15 Thread Darryl Thayer 
When I did my study of solar water heating I found that PV water heating
gave more hot water at a lower cost than solar thermal.  the Heatpump water
heater was the big winner.

On Thu, Mar 15, 2018 at 12:00 PM, Drake <
drake.chamber...@redwoodalliance.org> wrote:

> This discussion has been a great help. The house is built and the plumbing
> is in, but could be modified. Wood stoves are not a likely solution. I
> think we need a different water heating strategy.
>
> Thank you all!
>
> Drake
>
>
>
> At 09:21 AM 3/15/2018, you wrote:
>
> Content-Type: multipart/alternative;
>  boundary="EE4E9806B711DEF636076840"
> Content-Language: en-US
>
> This is what I came up with:
>
> The calculation is Q = mcp delta T
>
> Water Temp out =Â  120
>
> Water Temp in = ground source Temperature @ 50F?
>
> delta T = 70F
>
> m =  mass flow rate.  ASHRAE is the source for this. 20gals per person
> per day = 20 gallons x 8.34 lbs/gallon =Â  167lbs/day/person
>
> cp =Â  1 BTU/lb-degree F
>
> Q = 167 x 1 x 70 = 11,676 BTU/day/person
>
> Divide this by the efficiency of the water heating system (I'll assume =
> .86)Â  =11,676/.86 = 13, 577 BTU/person/day
>
> convert to kWh if necessarym 13,577/3412 = ~4 kWh/person/day, 120 kWh/month
>
> I checked this against one month and it seems reasonable.
>
> Website assuming ~3.5 family size comes up with @ 400kWh per month. They
> approached it another way with assuming run times.
>
> https://www.google.com/search?safe=active=hp=
> Z3KqWvXiNsGb5wKJ2Kf4DA=electric+water+heater+use+annual+consumption=
> electric+water+heater+use+annually_l=psy-ab.1.2.
> 33i22i29i30k1l3.279.9222.0.12475.35.19.0.7.7.0.451.2360.
> 0j6j4j0j1.11.00...1c.1.64.psy-ab..18.16.1952.0..
> 0j0i67k1j0i131k1j0i22i30k1.0.CiU8wYZigpI
>
>
> Chris
>
>
>
>
> On 3/15/2018 8:09 AM, Mike Kocsmiersky wrote:
>
> Barton makes a good point with regards to the incoming ground water
> temperature and the amount of heat required to bring it up to shower temp.
> Â My recollection is that ASHRAE states 20gal/person/day for the first 2
> people, then 15gpd or 12gpd thereafter.  However those rates vary wildly
> with consumers, from those that never bathe to the high schooler that needs
> 3 showers a day.  In the northeast water heating can be up to 19% of the
> total household energy load for the year.  Also, I would recommend the air
> source heat pump water heaters if you have significant humidity or an on
> demand unit.  Water tanks are typically under insulated and can lose
> 2kWh/day in standby losses.
> Â
> Mike Kocsmiersky
> Principal
> Spirit Solar Inc.
> (413) 734-1456
> Â
> Â
> Â
> *From:* Barton Churchill [mailto:bar...@solarips.com <bar...@solarips.com>]
>
> *Sent:* Wednesday, March 14, 2018 7:31 PM
> *To:* RE-wrenches
> *Subject:* Re: [RE-wrenches] Electric Water kWh/ person
> Â
> You first need to know your ground temperature. Then figure a delta to 100
> or so degrees. Most but not all showerheads flow 2.5gpm and showers are
> typically 10 minutes. You can then find a calculator online to calculate
> how many Btus are required to raise water temp for your delta per gallon.
> Convert to kWh, add some contingency and you should be good.Â
>
> On Wednesday, March 14, 2018, < drake.chamber...@redwoodalliance.org>
> wrote:
> Hello Wrenches,
>
> Is there a good way to estimate the power that will be consumed for
> electric water per person per day? We are estimating the amount of power
> that will be used by an all electric duplex, and the water heater amount
> seems high. The current model we have claims 3493 kWh/ year per 26 gallon
> tank will be consumed. With the two units, that would add up to 6986 kWh /
> year for hot water, pushing the system size to humongous for a 1300 ft sq
> building.
>
> Does that seem high? There will be a maximum of 2 people per unit.
>
> The owner is considering going to 115 V units with a 15 gallon tanks. I
> think the smaller tank would help, but it would seem that the amount of hot
> water consumed would be the main issue.
>
> How can we get a good estimate for a per person energy usage for electric
> hot water? Any other suggestions are welcome.
>
> Thank you,
>
> Drake
>
>
>
> --
> --Â
> Barton Churchill
> 406.587.5295 <(406)%20587-5295> Â
> 2430 North 7th Bozeman, MT 59715
> www.solarips.com
> [image: Image removed by sender.]
> Â
>
>
>
> ___
> List sponsored by Redwood Alliance
>
> List Address:
> RE-wrenches@lists.re-wrenches.org
>
> Change listserver email address & settings:
> http://lists.re-

Re: [RE-wrenches] Electric Water kWh/ person

2018-03-15 Thread Drake 
This discussion has been a great help. The house 
is built and the plumbing is in, but could be 
modified. Wood stoves are not a likely solution. 
I think we need a different water heating strategy.


Thank you all!

Drake



At 09:21 AM 3/15/2018, you wrote:

Content-Type: multipart/alternative;
 boundary="EE4E9806B711DEF636076840"
Content-Language: en-US

This is what I came up with:

The calculation is Q = mcp delta T

Water Temp out =Â  120

Water Temp in = ground source Temperature @ 50F?

delta T = 70F

m =  mass flow rate.  ASHRAE is the source for 
this. 20gals per person per day = 20 gallons x 
8.34 lbs/gallon =Â  167lbs/day/person


cp =Â  1 BTU/lb-degree F

Q = 167 x 1 x 70 = 11,676 BTU/day/person

Divide this by the efficiency of the water 
heating system (I'll assume = .86)Â  =11,676/.86 = 13, 577 BTU/person/day


convert to kWh if necessarym 13,577/3412 = ~4 kWh/person/day, 120 kWh/month

I checked this against one month and it seems reasonable.

Website assuming ~3.5 family size comes up with 
@ 400kWh per month. They approached it another way with assuming run times.


<https://www.google.com/search?safe=active=hp=Z3KqWvXiNsGb5wKJ2Kf4DA=electric+water+heater+use+annual+consumption=electric+water+heater+use+annually_l=psy-ab.1.2.33i22i29i30k1l3.279.9222.0.12475.35.19.0.7.7.0.451.2360.0j6j4j0j1.11.00...1c.1.64.psy-ab..18.16.1952.0..0j0i67k1j0i131k1j0i22i30k1.0.CiU8wYZigpI>https://www.google.com/search?safe=active=hp=Z3KqWvXiNsGb5wKJ2Kf4DA=electric+water+heater+use+annual+consumption=electric+water+heater+use+annually_l=psy-ab.1.2.33i22i29i30k1l3.279.9222.0.12475.35.19.0.7.7.0.451.2360.0j6j4j0j1.11.00...1c.1.64.psy-ab..18.16.1952.0..0j0i67k1j0i131k1j0i22i30k1.0.CiU8wYZigpI


Chris




On 3/15/2018 8:09 AM, Mike Kocsmiersky wrote:
Barton makes a good point with regards to the 
incoming ground water temperature and the 
amount of heat required to bring it up to 
shower temp. Â My recollection is that ASHRAE 
states 20gal/person/day for the first 2 people, 
then 15gpd or 12gpd thereafter.  However those 
rates vary wildly with consumers, from those 
that never bathe to the high schooler that 
needs 3 showers a day.  In the northeast water 
heating can be up to 19% of the total household 
energy load for the year.  Also, I would 
recommend the air source heat pump water 
heaters if you have significant humidity or an 
on demand unit.  Water tanks are typically 
under insulated and can lose 2kWh/day in standby losses.

Â
Mike Kocsmiersky
Principal
Spirit Solar Inc.
(413) 734-1456
Â
Â
Â
From: Barton Churchill 
[<mailto:bar...@solarips.com>mailto:bar...@solarips.com]

Sent: Wednesday, March 14, 2018 7:31 PM
To: RE-wrenches
Subject: Re: [RE-wrenches] Electric Water kWh/ person
Â
You first need to know your ground temperature. 
Then figure a delta to 100 or so degrees. Most 
but not all showerheads flow 2.5gpm and showers 
are typically 10 minutes. You can then find a 
calculator online to calculate how many Btus 
are required to raise water temp for your delta 
per gallon. Convert to kWh, add some contingency and you should be good.Â


On Wednesday, March 14, 2018, 
<<mailto:drake.chamber...@redwoodalliance.org>drake.chamber...@redwoodalliance.org> 
wrote:

Hello Wrenches,

Is there a good way to estimate the power that 
will be consumed for electric water per person 
per day? We are estimating the amount of power 
that will be used by an all electric duplex, 
and the water heater amount seems high. The 
current model we have claims 3493 kWh/ year per 
26 gallon tank will be consumed. With the two 
units, that would add up to 6986 kWh / year for 
hot water, pushing the system size to humongous for a 1300 ft sq building.


Does that seem high? There will be a maximum of 2 people per unit.

The owner is considering going to 115 V units 
with a 15 gallon tanks. I think the smaller 
tank would help, but it would seem that the 
amount of hot water consumed would be the main issue.


How can we get a good estimate for a per person 
energy usage for electric hot water? Any other suggestions are welcome.


Thank you,

Drake



--
--Â
Barton Churchill
406.587.5295 Â
2430 North 7th Bozeman, MT 59715
<http://www.solarips.com/>www.solarips.com
Image removed by sender.

Â



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Re: [RE-wrenches] Electric Water kWh/ person

2018-03-15 Thread Darryl Thayer 
Sorry I could not find much data but here is what I found

Here is some of my data, take with a grain of sault.

Well pump ½ hp drawdown 60 feet, start surge 1500 Watts running watts 500
watts runtime 25 seconds 40-gallon bladder tank.  40 to 60 PSI.

Two people in the house about 60 years old, One shower the pump ran 4 or
sometimes 5 cycles of the water pump about 30 seconds on and 30 off.  This
means they ran water for about 4 or 5 minutes per shower.  When no one was
home the electric water 50-gallon energy star cycled about 4 times per day,
at 4500 watts for about 10 min,  just the non use water heater used 2.5
kWh/day when it was not in use.


Another example Family of three, heat pump water heater, energy conscious,
3 showers per day energy use was 1500 Watt hr/day.  If HP had COP of 4 then
equivalent to 6,000 Wh/d if it had been electric.  This means the family
was using 40 gallons /day for 3 people or about 13.5 gallons per person per
day.



Garage door opener 700 watts running very small surge, 2 car garage door,
typically 4 cycles per day, run time 12 seconds open and 12 seconds close.

 Refrigerator energy star about 50% duty cycle 100 watts on,  or 1200 Wh/d
Family of two 60-year-olds.


I have much more data but I could not find.


On Thu, Mar 15, 2018 at 8:42 AM, frenergy  wrote:

> Drake,
>
> It would help to knowis this duplex already built? and
> considering where you live, is a woodstove being considered for space heat?
>
> Bill
>
> Feather River Solar Electric
> Bill Battagin, Owner
> 4291 Nelson St.
> Taylorsville, CA 95983530.284.7849 <(530)%20284-7849>
> CA Lic 874049www.frenergy.net
>
> On 3/14/2018 4:19 PM, drake.chamber...@redwoodalliance.org wrote:
>
> Hello Wrenches,
>
> Is there a good way to estimate the power that will be consumed for
> electric water per person per day? We are estimating the amount of power
> that will be used by an all electric duplex, and the water heater amount
> seems high. The current model we have claims 3493 kWh/ year per 26 gallon
> tank will be consumed. With the two units, that would add up to 6986 kWh /
> year for hot water, pushing the system size to humongous for a 1300 ft sq
> building.
>
> Does that seem high? There will be a maximum of 2 people per unit.
>
> The owner is considering going to 115 V units with a 15 gallon tanks. I
> think the smaller tank would help, but it would seem that the amount of hot
> water consumed would be the main issue.
>
> How can we get a good estimate for a per person energy usage for electric
> hot water? Any other suggestions are welcome.
>
> Thank you,
>
> Drake
>
>
>
>
> ___
> List sponsored by Redwood Alliance
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Re: [RE-wrenches] Electric Water kWh/ person

2018-03-15 Thread frenergy 

Drake,

            It would help to knowis this duplex already built? and 
considering where you live, is a woodstove being considered for space heat?


Bill

Feather River Solar Electric
Bill Battagin, Owner
4291 Nelson St.
Taylorsville, CA 95983
530.284.7849
CA Lic 874049
www.frenergy.net

On 3/14/2018 4:19 PM, drake.chamber...@redwoodalliance.org wrote:

Hello Wrenches,

Is there a good way to estimate the power that will be consumed for 
electric water per person per day? We are estimating the amount of 
power that will be used by an all electric duplex, and the water 
heater amount seems high. The current model we have claims 3493 kWh/ 
year per 26 gallon tank will be consumed. With the two units, that 
would add up to 6986 kWh / year for hot water, pushing the system size 
to humongous for a 1300 ft sq building.


Does that seem high? There will be a maximum of 2 people per unit.

The owner is considering going to 115 V units with a 15 gallon tanks. 
I think the smaller tank would help, but it would seem that the amount 
of hot water consumed would be the main issue.


How can we get a good estimate for a per person energy usage for 
electric hot water? Any other suggestions are welcome.


Thank you,

Drake




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Re: [RE-wrenches] Electric Water kWh/ person

2018-03-15 Thread cwarfel 

This is what I came up with:

The calculation is Q = mcp delta T

Water Temp out =  120

Water Temp in = ground source Temperature @ 50F?

delta T = 70F

m = mass flow rate.  ASHRAE is the source for this. 20gals per person 
per day = 20 gallons x 8.34 lbs/gallon =  167lbs/day/person


cp =  1 BTU/lb-degree F

Q = 167 x 1 x 70 = 11,676 BTU/day/person

Divide this by the efficiency of the water heating system (I'll assume = 
.86)  =11,676/.86 = 13, 577 BTU/person/day


convert to kWh if necessarym 13,577/3412 = ~4 kWh/person/day, 120 kWh/month

I checked this against one monthand it seems reasonable.

Website assuming ~3.5 family size comes up with @ 400kWh per month. They 
approached it another way with assuming run times.


https://www.google.com/search?safe=active=hp=Z3KqWvXiNsGb5wKJ2Kf4DA=electric+water+heater+use+annual+consumption=electric+water+heater+use+annually_l=psy-ab.1.2.33i22i29i30k1l3.279.9222.0.12475.35.19.0.7.7.0.451.2360.0j6j4j0j1.11.00...1c.1.64.psy-ab..18.16.1952.0..0j0i67k1j0i131k1j0i22i30k1.0.CiU8wYZigpI


Chris




On 3/15/2018 8:09 AM, Mike Kocsmiersky wrote:


Barton makes a good point with regards to the incoming ground water 
temperature and the amount of heat required to bring it up to shower 
temp.  My recollection is that ASHRAE states 20gal/person/day for the 
first 2 people, then 15gpd or 12gpd thereafter.  However those rates 
vary wildly with consumers, from those that never bathe to the high 
schooler that needs 3 showers a day.  In the northeast water heating 
can be up to 19% of the total household energy load for the year.  
Also, I would recommend the air source heat pump water heaters if you 
have significant humidity or an on demand unit. Water tanks are 
typically under insulated and can lose 2kWh/day in standby losses.


Mike Kocsmiersky

Principal

Spirit Solar Inc.

(413) 734-1456

*From:*Barton Churchill [mailto:bar...@solarips.com]
*Sent:* Wednesday, March 14, 2018 7:31 PM
*To:* RE-wrenches
*Subject:* Re: [RE-wrenches] Electric Water kWh/ person

You first need to know your ground temperature. Then figure a delta to 
100 or so degrees. Most but not all showerheads flow 2.5gpm and 
showers are typically 10 minutes. You can then find a calculator 
online to calculate how many Btus are required to raise water temp for 
your delta per gallon. Convert to kWh, add some contingency and you 
should be good.


On Wednesday, March 14, 2018, <drake.chamber...@redwoodalliance.org 
<mailto:drake.chamber...@redwoodalliance.org>> wrote:


Hello Wrenches,

Is there a good way to estimate the power that will be consumed for 
electric water per person per day? We are estimating the amount of 
power that will be used by an all electric duplex, and the water 
heater amount seems high. The current model we have claims 3493 kWh/ 
year per 26 gallon tank will be consumed. With the two units, that 
would add up to 6986 kWh / year for hot water, pushing the system size 
to humongous for a 1300 ft sq building.


Does that seem high? There will be a maximum of 2 people per unit.

The owner is considering going to 115 V units with a 15 gallon tanks. 
I think the smaller tank would help, but it would seem that the amount 
of hot water consumed would be the main issue.


How can we get a good estimate for a per person energy usage for 
electric hot water? Any other suggestions are welcome.


Thank you,

Drake



--

--

Barton Churchill
406.587.5295
2430 North 7th Bozeman, MT 59715
www.solarips.com <http://www.solarips.com/>

Image removed by sender.



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--

 Christopher Warfel, PE
   ENTECH Engineering, Inc.
PO Box 871, Block Island, RI 02807
   (401)466-8978

EEI logo <http://entech-engineering.com>
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Re: [RE-wrenches] Electric Water kWh/ person

2018-03-15 Thread Bill Hennessy 
Drake--
The kWh numbers are reasonable. A few years ago, I metered our hot water heater 
for a family of three and we were using an average of 10kWh/day--about 
one-third of our electric bill. A heat-pump water heater will reduce the kWhs, 
but they cost more and are louder. A better insulated water heater, insulated 
supply lines, low flow fixtures and better consumption awareness would also 
help reduce energy use.

regards, bill Bill Hennessy
Berks Solar, LLC
371 Centennial Rd
Mertztown, PA 19539

o 610 682 4300
c 484 560 4666
NABCEP certified installer
PA contractor #44411
www.berkssolar.com

  From: "drake.chamber...@redwoodalliance.org" 
<drake.chamber...@redwoodalliance.org>
 To: RE-wrenches <re-wrenches@lists.re-wrenches.org> 
 Sent: Wednesday, March 14, 2018 7:19 PM
 Subject: [RE-wrenches] Electric Water kWh/ person
   
Hello Wrenches,

Is there a good way to estimate the power that will be consumed for electric 
water per person per day? We are estimating the amount of power that will be 
used by an all electric duplex, and the water heater amount seems high. The 
current model we have claims 3493 kWh/ year per 26 gallon tank will be 
consumed. With the two units, that would add up to 6986 kWh / year for hot 
water, pushing the system size to humongous for a 1300 ft sq building. 

Does that seem high? There will be a maximum of 2 people per unit. 

The owner is considering going to 115 V units with a 15 gallon tanks. I think 
the smaller tank would help, but it would seem that the amount of hot water 
consumed would be the main issue. 

How can we get a good estimate for a per person energy usage for electric hot 
water? Any other suggestions are welcome.

Thank you,

Drake


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Re: [RE-wrenches] Electric Water kWh/ person

2018-03-15 Thread Mike Kocsmiersky 
Barton makes a good point with regards to the incoming ground water temperature 
and the amount of heat required to bring it up to shower temp.  My recollection 
is that ASHRAE states 20gal/person/day for the first 2 people, then 15gpd or 
12gpd thereafter.  However those rates vary wildly with consumers, from those 
that never bathe to the high schooler that needs 3 showers a day.  In the 
northeast water heating can be up to 19% of the total household energy load for 
the year.  Also, I would recommend the air source heat pump water heaters if 
you have significant humidity or an on demand unit.  Water tanks are typically 
under insulated and can lose 2kWh/day in standby losses.

 

Mike Kocsmiersky

Principal

Spirit Solar Inc.

(413) 734-1456

 

 

 

From: Barton Churchill [mailto:bar...@solarips.com] 
Sent: Wednesday, March 14, 2018 7:31 PM
To: RE-wrenches
Subject: Re: [RE-wrenches] Electric Water kWh/ person

 

You first need to know your ground temperature. Then figure a delta to 100 or 
so degrees. Most but not all showerheads flow 2.5gpm and showers are typically 
10 minutes. You can then find a calculator online to calculate how many Btus 
are required to raise water temp for your delta per gallon. Convert to kWh, add 
some contingency and you should be good. 

On Wednesday, March 14, 2018, <drake.chamber...@redwoodalliance.org> wrote:

Hello Wrenches,

Is there a good way to estimate the power that will be consumed for electric 
water per person per day? We are estimating the amount of power that will be 
used by an all electric duplex, and the water heater amount seems high. The 
current model we have claims 3493 kWh/ year per 26 gallon tank will be 
consumed. With the two units, that would add up to 6986 kWh / year for hot 
water, pushing the system size to humongous for a 1300 ft sq building. 

Does that seem high? There will be a maximum of 2 people per unit. 

The owner is considering going to 115 V units with a 15 gallon tanks. I think 
the smaller tank would help, but it would seem that the amount of hot water 
consumed would be the main issue. 

How can we get a good estimate for a per person energy usage for electric hot 
water? Any other suggestions are welcome.

Thank you,

Drake





-- 

-- 

Barton Churchill
406.587.5295  
2430 North 7th Bozeman, MT 59715
 <http://www.solarips.com/> www.solarips.com

Image removed by sender.

 

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Re: [RE-wrenches] Electric Water kWh/ person

2018-03-15 Thread jerrysgarage01 


DrakeWe have used 40 to 80 gallon water heaters mainly the Rheem Marathon 
electric units, we used 15 minutes per person twice a day on the timer, we did 
use 7 day timers to have different start times on the weekends. We had great 
success with that as a base line.Jerry


Sent from my Verizon, Samsung Galaxy smartphone

 Original message 
From: Darryl Thayer <darylsol...@gmail.com> 
Date: 3/14/18  4:14 PM  (GMT-10:00) 
To: RE-wrenches <re-wrenches@lists.re-wrenches.org> 
Subject: Re: [RE-wrenches] Electric Water kWh/ person 

Sorry to say nothing, but a few years ago I did a study on off grid and on grid 
houses and some had electric resistance water heaters and one with a Heat pump 
water heater.  If I can find the data I will send.  However, it varied a lot 
most the families were for 2 or 3 people  The variation made it seem like my 
study was of little value.  except for the family with a heat pump water heater 
used about 1/4 the electricity of the other.    
On Wed, Mar 14, 2018 at 6:19 PM,  <drake.chamber...@redwoodalliance.org> wrote:
Hello Wrenches,

Is there a good way to estimate the power that will be consumed for electric 
water per person per day? We are estimating the amount of power that will be 
used by an all electric duplex, and the water heater amount seems high. The 
current model we have claims 3493 kWh/ year per 26 gallon tank will be 
consumed. With the two units, that would add up to 6986 kWh / year for hot 
water, pushing the system size to humongous for a 1300 ft sq building. 

Does that seem high? There will be a maximum of 2 people per unit. 

The owner is considering going to 115 V units with a 15 gallon tanks. I think 
the smaller tank would help, but it would seem that the amount of hot water 
consumed would be the main issue. 

How can we get a good estimate for a per person energy usage for electric hot 
water? Any other suggestions are welcome.

Thank you,

Drake




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Re: [RE-wrenches] Electric Water kWh/ person

2018-03-14 Thread Darryl Thayer 
Sorry to say nothing, but a few years ago I did a study on off grid and on
grid houses and some had electric resistance water heaters and one with a
Heat pump water heater.  If I can find the data I will send.  However, it
varied a lot most the families were for 2 or 3 people
 The variation made it seem like my study was of little value.  except for
the family with a heat pump water heater used about 1/4 the electricity of
the other.

On Wed, Mar 14, 2018 at 6:19 PM, 
wrote:

> Hello Wrenches,
>
> Is there a good way to estimate the power that will be consumed for
> electric water per person per day? We are estimating the amount of power
> that will be used by an all electric duplex, and the water heater amount
> seems high. The current model we have claims 3493 kWh/ year per 26 gallon
> tank will be consumed. With the two units, that would add up to 6986 kWh /
> year for hot water, pushing the system size to humongous for a 1300 ft sq
> building.
>
> Does that seem high? There will be a maximum of 2 people per unit.
>
> The owner is considering going to 115 V units with a 15 gallon tanks. I
> think the smaller tank would help, but it would seem that the amount of hot
> water consumed would be the main issue.
>
> How can we get a good estimate for a per person energy usage for electric
> hot water? Any other suggestions are welcome.
>
> Thank you,
>
> Drake
>
>
>
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Re: [RE-wrenches] Electric Water kWh/ person

2018-03-14 Thread Barton Churchill 
You first need to know your ground temperature. Then figure a delta to 100
or so degrees. Most but not all showerheads flow 2.5gpm and showers are
typically 10 minutes. You can then find a calculator online to calculate
how many Btus are required to raise water temp for your delta per gallon.
Convert to kWh, add some contingency and you should be good.

On Wednesday, March 14, 2018,  wrote:

> Hello Wrenches,
>
> Is there a good way to estimate the power that will be consumed for
> electric water per person per day? We are estimating the amount of power
> that will be used by an all electric duplex, and the water heater amount
> seems high. The current model we have claims 3493 kWh/ year per 26 gallon
> tank will be consumed. With the two units, that would add up to 6986 kWh /
> year for hot water, pushing the system size to humongous for a 1300 ft sq
> building.
>
> Does that seem high? There will be a maximum of 2 people per unit.
>
> The owner is considering going to 115 V units with a 15 gallon tanks. I
> think the smaller tank would help, but it would seem that the amount of hot
> water consumed would be the main issue.
>
> How can we get a good estimate for a per person energy usage for electric
> hot water? Any other suggestions are welcome.
>
> Thank you,
>
> Drake
>
>
>

-- 
-- 
Barton Churchill
406.587.5295
2430 North 7th Bozeman, MT 59715
www.solarips.com
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[RE-wrenches] Electric Water kWh/ person

2018-03-14 Thread drake . chamberlin 
Hello Wrenches,

Is there a good way to estimate the power that will be consumed for
electric water per person per day? We are estimating the amount of
power that will be used by an all electric duplex, and the water
heater amount seems high. The current model we have claims 3493 kWh/
year per 26 gallon tank will be consumed. With the two units, that
would add up to 6986 kWh / year for hot water, pushing the system size
to humongous for a 1300 ft sq building. 

Does that seem high? There will be a maximum of 2 people per unit. 

The owner is considering going to 115 V units with a 15 gallon tanks.
I think the smaller tank would help, but it would seem that the amount
of hot water consumed would be the main issue. 

How can we get a good estimate for a per person energy usage for
electric hot water? Any other suggestions are welcome.

Thank you,

Drake


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