Re: [RE-wrenches] Electric Water kWh/ person
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 Date: 3/14/18 4:14 PM (GMT-10:00) To: RE-wrenches 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, 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 List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
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, 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 > > List Address: RE-wrenches@lists.re-wrenches.org > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches. > org/maillist.html > > List rules & etiquette: > www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > www.members.re-wrenches.org > > > ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
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, 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 ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
[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 ___ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out or update participant bios: www.members.re-wrenches.org
