U is in Watts. R is 1/U. Not too hard and universal. I also tire of the comparisons of kcal and BTU's, W and HP, but that is the language of heating ventilating and air conditioning. As an engineer, I just have to be good at making the conversions. I was raised on customary units, educated in SI, and they coexist. That is just the way it is. Electricity is sort of an oasis of less complicated units.
In the US they like to put R on insulation materials. It maps to the mind better than U. The better the insulation, the higher the number. If it were U, then the better insulation would have smaller numbers and more decimal points. Not so easy. An important point about insulating things: beyond a certain point, it is a waste of time and money. For the relatively small temperature differences that drive heat transfer in at habitable temperatures, R of 100 or something is silly. Pretty soon you are going to open a door and the petty gains will be blown away. This where working through the calculations as Roland has done will be educational. If you work it out with and R of 10, then plug in R= 30, 50 , 100, you can get a feel for what is gained. Basic texts on heat transfer are worth looking at. You can get non-calculus based explanations, but calculus is nice because it is the math of change. And this is all bout temperatures changing. Frank makes a good point about the differences between free and forced convection, they are very different, but R still makes the hot and cold sides "less available to each other" in a time sense. BentMike On Sun, Oct 13, 2013 at 9:08 AM, Hoegberg . <[email protected]> wrote: > I think this "Another method of heating an Ev" - story below was > interesting, but I did not understand it first, as I was reading it to > fast. But not even so after second slow reading could I make it trough > this message. No offence, It is not bad, Its just me. > > > The SHORT: > > Sugestion: > -Again, no offense all people of other small unknown cultures, ..but some > Irony might have been added. :-) > > As this is an international list, please can we try to use the normal > units that we all(almost) have used now for 100+ years) And many have used > them since year year 1795 just to to clean up the international > bad-unit-mess that we had way back then over 100-200 years ago. Please try > hard and your very best now and not fall back to the older, harder and > highly local unknown ones and/or other bad habits. > > Of Course We can also continue to cripplecode some messages, but I dont > think you will like for example all our older local Swedish units. :-) > > > > Let The LONG unit rant begin: > (for a deeper understanding of the problem, ..or not.. :-) > > F = it seems not linear. Please use Celsius or kelvin ? > BTU = use Watt and Hours(?) > USATU = Watt and Hours > HP = please we must KILL all the indicated, british or braked or the > invented electrical Horses.. > > For example: > lets measure the A/C equipments cooling capacity in parts of a highly > unknown animal. Really?? Cant be the very best method, or is it? > > R-factor = I dont know about this, but I assume it IS international for > insulation calculations? Local here it was "K-value", but nowdays I think > it is "U-value".. :-) > > 300 W of cu bi heating of unknown or generic gas(probably not the > Super-"gas" they have in gas stations) = ? > complicated! > > 4 wire = ? Maybe an easy calculation, but I dont know it. > > > > But what about MILES? > > mile = Hmm, Is it English, brittish or imperium (is it the same > imperialistic mile?), or is it the local states in 1 other countrys roads, > or maybe texas-land area-mile, or international nautical miles or ..is it > just a normal(NEW) Swedish mil? :-) > Who knows, > > Ok, But how LONG is this "international" mile? > = 1852 I guess! As it seems to be the only commonly used mile nowdays, > > -Cool! So Can we use this? > Well, yes we can! ..BUT this sometimes seems to be mixed up with The > Imperialistic (UK) nautical mile someone might refer to...., That is > exactly 6,080 international feets = 1853,184 m but abandoned in 1970, so > all older references are now converted to 1 85_3_,000 meters exactly here.. > > The USA-mile was 1853,248 metres here before. > (6,080.20 U.S.A feets, based on the definition of the foots recently in > 1893. it was also abandoned. and their feet grows bigger when they get > richer and can buy more food) > > English usage of sea mile varies from about 1,855.3 metres to to about > 1,849.1 metres I beleve, So you must know exactly where you are at the > moment (?), to know how long you have traveled. But in "average" you are > close to almost correct if you use 1,85_2_.3 metres average, but you will > probably hit the ground hard sometimes.. > > > > -Ok, puh.. Is it really that HARD for us to agree to keep one mile > distance? > > Yes, and then there is the geographical "mile"... > It is the length of one minute of longitude along the Equator, about > 1,85_5_.4 m (on the International (1924) Spheroid )or about 1,855.325 m on > the WGS 84 ellipsoid. (Bowditch defines it as 6,087.08 feet, which is > 1,855.34 metres. But it looks close to the English seamile? -Yes, in some > places, sometimes..) > > AND PLEASE Do not confuse this with the similar-sounding unit the > geografische Meile, in German measurements. The length of FOUR minutes of > arc along the equator, standardized as 7,421.6 metres. > > In the USA nowdays a "Metric Mile" is exactly 1600 long. (?) > But all other countries just ignore them, as it is known to be 1500. > > In Germany, the Mile , Uhr or Stunde > typically refers to 24,000 local feet = the distance one might walk in an > hour (Stunde) if he likes to do that.And sadly there is also the tactical > "mile" or data "mile" used by some navies = 6,000 of local(?)feets of > somewhere, but known to be (1,828.8 m) . In the Royal Navy, this is also > known as a data mile.- SO.. seems a bit complicated with this > "mile"-thing ! Therefore I suggest that WE ALL now agree to use the > Swedish "Mil" instead! It is the perfect Mile!! Also I am most used to > this one, so I assume that all of you must agree on this, it is clearly the > future of units. > > > > ""The traditional Swedish mil spanned the range from 6000–14,485 metres, > depending on province you had to visit. It was however standardized in 1649 > to 36,000 Swedish feet.. or 10.687 km. The Norwegian mil was 11.298 > kilometres. When the metric system was introduced in the Norwegian-Swedish > union in 1889, it standardized the mil to exactly 10 kilometres. Mil is > still commonly used when measuring fuel consumption in vehicles; e.g., 0.5 > litre per mil."" > > > And there is *a LOT* of other "miles" out there, for example the Roman > imperium mile, or 20+ (?) other ones here: > http://en.wikipedia.org/wiki/Mile > > I beleve Finland have also had at least 3-4 different "mile", depending on > who invades their country for the moment, maybe some mil from .se, and some > of the .ru miles and also the local Finnland-mile, -Jukka, is this > correct? > > > > > wow.. > > Here is some other local units, that might ,or not, have been used here on > the list: > > " 1/231 us-inch of 100 Gauges of copper wire" = how many mm^2 is that? > > How many Swedish "verktum"-inch will it be compared to us-inch? > > square fots of unknown size per punds of usa-inches = ? > > > > Gallons in a mile of electricity, "eGallon" (of unknown local usa-sizes?) > = ? > How many kWh / 100km is that? Or how many kWh / Swedish mile ? :-) > > gallon per mile (uk) = ?? > > Psi(PascalPer..local inches in nice squares) = unknown sized inch ? > 100000 Pascal =1Bar , > or use maybe inexact but close enough: kg/cm2, or Atm that is more easy > to relate to. > > quarterpoundr (Kilogram) per usafoot (meter) = N m ? > > mile of roads (usa)=1.6xxx km > mile of maps or land(United states) =1.xxxxx km > mile (United kingdoms) = 1.xxxxxx km ? > mil (United Sweeds) = 10 km > > mm 0.001 meter > meter = 1 meter > km =1000 meter > > ton =1000 kg > kg = 1000 gram > > > > -But what is 1 lb / sqft = ? > Its easy: > " libra or libbra (lb)a traditional unit of weight in Italian, Spanish, > and Portuguese speaking countries. The libra was the Roman unit from > which the English pound is descended; the symbol "lb" for the pound > comes from this unit. The Roman libra contained only 12 unciae (ounces) > and was about 0.722 English pound. The traditional Italian libbra was > often of similar size, but a wide variety of libbras were used in > Italian markets over the centuries. The Spanish and Portuguese units > are larger, generally in the range from 1.011 to 1.016 English pound > (very close to 460 grams). The Spanish libra equals 16 onzas, and the > Portuguese libra equals 16 onças. The word "libra" is sometimes used > now for the kilogram, a much larger unit." > > No, of course it is just the Swedish "lb" beeing used here: > = SkeppsPund "ShipPound" = 1 skeppund = 20 lispund , as well known that > 1 lis pund = 20 skålpund and if you know that 1 <lb> = 1 skålpund will be > = 32 "lod", ..as 1 lod = 4 kvintin (or "quarts"?). Now it is very easy > to just do the math, as we all know 1 kvintin was ~= 10^-2.47874 kg > > Then we just have to devide that by 1/6 (maybe) of the email-senders > countrys average humans height at some agreed year. (we are toold in school > that sometimes in some foreign old cultures feets (foot) is 1/6 of the > lenght(height) of their older humans(but they are all dead now, so we cant > really measure that) ) and then we put them all in 90 degrees and multiply > them? ..Or someting like that, I cant really describe it but seriously we > all know exactly what we mean, so I assume we can finally all agree on THIS > one, at least? ..right? > > > > Great! > > -Now I only need to find my new EU-banned 60 Newtonmeter per second of > metric light-bulbs for my kitchen, so I can see what I make for dinner.. > > > / John > > > > > > ---------------------------------------- > > From: [email protected] > > To: [email protected] > > Date: Fri, 11 Oct 2013 09:31:58 -0600 > > Subject: [EVDL] Another method of heating a EV > > > > Receiving my first EV call Transformer I which was a converted 75 > Chevelle, The company, Electric Fuel Propulsion added some additional > heating systems for my car which was to driven in Montana and steep hills. > > > > The power to drive the heating system or the A/C system does not come > from the main battery pack which was 90 cells lead cells rated at 2.2 volts > 180 volt battery pack. If you let the battery cold soak down to 30 degrees > which I did only one time to see what the effects it would have. > > > > At a 80F - 30F temperature differential, I can actually add about 25 > volts to the normal charging volts of 225 vdc at 80F to about 250 vdc to > the battery at 30F. > > > > Before the EV would leave the garage, which the walls were insulated to > 55 R-factor, the ceiling to 110 R-Factor and the garage door is a foam door > at 20 R-Factor. The heat lost at 30 below 0 maintaining a inside > temperature of 70 F becomes about 1200 btu's per hour is about a 300 watt > heating or a 1/3 cu bi feet of gas heating. > > > > Having the main charging cable plug in all the time which is a 4 wire > 125/250 vac, the on board heater of 640 watts come on about 15 minutes > before I leave. The inside temperature will be at 80 F degrees when I > leave. I do not have to use the on board power for at least 2 miles of my > drive. > > > > I have the option of switching the 3 position selector switch from > Commercial Power to the on board Inverter Power. Because of the roller > coaster hills we have, the on board power only comes on when I let up on > the accelerator. This activates a relay which turns on a contactor for the > heating system which consist of a 640W, 860W cabin heat and a 1000 watt > water heater. > > > > Going down hill the motor still turns which drives a 7 kw inverter > alternator. At this time when I look at the gages, my motor and battery > ampere is at 0 amperes and the inverter voltage is at 120 vac 60hz at 8 > amps for one heater and about 20 amps for all three heaters. > > > > The inverter alternator is a Delco unit design for utility vehicles. It > will also provide 12 to 15 volts DC up to 135 amperes. This 12 volt system > was also back up by a Honey Well motor generator which the motor is driven > by the 180 v battery pack. This unit had two pilot shafts that drives the > vacuum pump, power steering and A/C. > > > > Remove this motor generator and now belt only the A/C and Inverter > Alternator off the main motor pilot shaft. These units are off line when > the motor is under load and off when the motor is on load. > > > > Roland > > > > > > > > > > > > > > -------------- next part -------------- > > An HTML attachment was scrubbed... > > URL: < > http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20131011/3cd29f2b/attachment.htm > > > > _______________________________________________ > > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > > For EV drag racing discussion, please use NEDRA ( > http://groups.yahoo.com/group/NEDRA) > > > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > For EV drag racing discussion, please use NEDRA ( > http://groups.yahoo.com/group/NEDRA) > > -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * To invent, you need a good imagination and a pile of junk. Thomas A. Edison<http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html> A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 550-2430 Land (919) 576-0824 <https://www.google.com/voice/b/0?pli=1#phones> Google Phone (919) 631-1451 Cell (919) 513-0418 Desk [email protected] <[email protected]> -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20131013/9b58f326/attachment.htm> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
