"Using electric hot water tank to heat small living space".

Discussion recently someone claimed to have used a 40 US gallon electric hot water tank to heat a small living space by piping its output to a couple of radiators or hydro baseboards. It was AIUI a converted single bedroom cabin?

Presumably the hot water heater (tank) would have two 3000 watt elements. So 6000 watts would provide approx. 18,000 BTU or so of hot water per hour.

That sounds quite usable, recalling older less efficient hot air circulating oil fired furnaces for 3 bedroom plus full basement houses of 2000+ sq. feet in this rather cold climate which were often rated at around 45,000 BTU? As long as the water would circulate somehow?

Thanks for any comments?

Reply to
terry
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Hi Terry,

Others will no doubt offer their own take, but I would recommend a proper electric boiler and not a DHW tank; they're not that much more expensive and they're built for the long haul. Note too that with the exception of some high-capacity models, only the upper or lower element is energized at any one time -- not both.

In any event, you might also consider electric hot water baseboard units such as these:

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No boiler, expansion tank, circulator pump(s), zone value(s), plumbing lines and, most importantly, no worries about freeze-up in the event of an extended power outage or if you close up camp for the winter. Plus you can zone each room just as you do with regular electric baseboard heaters. These units provide a nice, gentle heat and they're *MUCH* safer than the standard variant. I highly recommend them.

Cheers, Paul

Reply to
Paul M. Eldridge

Are you in an area where electricity is as cheap per btu as fuels are. Few places in the US are. A water heater can work but wont last as long as proper equipment.

Reply to
ransley

I "can" work, but is certainly not the best method. If you are using that much electricity, why not just use electric baseboard and remove the need for circulating water?

Reply to
Edwin Pawlowski

most hot water tanks only heat one element at a time.

Reply to
hallerb

Check current limitations / fuses of your power supply. Here in Germany we get up to 16 Amps at 230 V out of the plug which gives a maximum of 3680 Watt. However, you should also check the complete wiring from fuse to tank sinc 16 A are quite a lot giving the possibility that thin wires may burn your house. Also check if the tank can run continuously or if it only stands short operatation periods.

virtuPIC

-- Airspace V - international hangar flying!

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Reply to
virtuPIC

Electric filament heaters are usually very expensive to run. And electric water heaters use filaments.

For twenty bucks, this person could buy a ceramic heater from Walmart or Home Depot, and plug it in to the wall. Get much the same output. The ceramic heaters are supposed to be safe, and more heat for the buck.

Sounds like too much equipment, for not much benefit.

Reply to
Stormin Mormon

If you are going electric, why bother heating water, moving water, protecting water from freezing, finding out you are cold after a shower since you used all the hot water, etc. Just use electric heat. That said, I would consider other sources like oil before going ahead. The cost might be quite a bit less for heat that way. Local cost vary a great deal, so you will need local information to make that decision.

Reply to
Joseph Meehan

=2E Thanks for all the comments.

I think part of the discussion was because electric hot water tanks are still a pretty cheap item. (around $200). And for a 'summer cabin' if it has electrical service at all the 30 or so amps for heating when the cabin is in use is not a major factor for what will be at least a 100 amp/115-230 volt service.

Interesting to see some differences between European and North American practice.

In North America one perceives many (most) hot water heater tanks are the 'always on', as opposed to 'instant' and have two elements, upper and lower each with a thermostat. The upper thermostats usually arranged as a 'flip-flop' .

The top element heats first and then flips over to the lower heater element. In other words (normally as shipped from factory) only one

3000 watt heater is on a a time.

BTW in this part of Canada most heaters are 40 US gallon (about 33 Imperial gallons) and have two 3000 watt, 230 volt, heating elements. However, daughters house has a 60 gallon version with i think, two

4500 watt elements, also arranged flip-flop.

It is possible very easily by moving one wire to alter so that both heater elements can come on at same time, each under control of its thermostat. That of course doubles the current flow (in our case for

6000 watts or about 26 amps).

Ours is wired with #10 AWG, good for 30 amps and a suitable breaker. Have only resorted to that arrangement once when we had a number of additional people staying with us.

As mentioned this is only discussion of an idea and as pointed out the additional complexity probably not worth while.

This (all electric) 38 year old house; about 1500 sq foot single storey main floor, 4 bedroom etc. is heated by electric baseboard convection heaters; with an occasional use wood stove in the mainly unheated full in ground concrete basement workshop below.

Averaged monthly total energy cost is $210 (which includes all taxes etc.). Or about $2500/yr. And it's a pretty cold and windy climate (Today May 9th for example it is +2 deg Celsius!).

Not sure why the statement; " Electric filament heaters are usually very expensive to run. And electric water heaters use filaments.... "

That electric filament heaters are 'more expensive' to run? Not understood. Electricity is electricity no matter how one turns it into heat! Or light, or cooking or TV viewing etc. For heating it's matter of cost whether it is more or less expensive that other fuels!

With current world prices of oil, here people are converting their homes from oil to electricity, no matter what type of existing heating they have, warm air, water etc. there are conversion units available.

Here much electrcity for about one half million people is generated by water (hydro) power; although oil is used in one thermal plant for peak winter backup and during emergencies such as ice storms.

Once again thanks for the ideas.

Reply to
terry

It will cost you more to change from baseboard in operating costs with a reduction in reliability. You will pay to pump water and loose in tank standby loss and plumbing loss, also the high temp you may need to heat might be to much for the water heater, it will also shorten its life. Your baseboards were designed for what they do, I dont see any benefit to changing. You are lucky to have subsidised cheap hydro. Put that extra money into insulation.

Reply to
ransley

Hmmm, Depending on your location, how about going solar?

Reply to
Tony Hwang

a SUPER INSULATED home needs no central heating at all.

google superinsulation.

you loose some room size but big long term payoff

Reply to
hallerb

Dreamin again I see, Where did you dream that up of not needing central heat, SIPS are super insulated, mine is super insulated. Even super insulated w/ passive solar needs additional heat, they just dont need as much Btu. Every home needs so many air exchanges per day, or you just get real sick. And what is your defination of super insulation.

Reply to
ransley

r

Ok I googled superinsulation, and I qualify, R 40 walls, R 100 attic[ shrunk to R 75] but I in zone 5 to - 20f. You need heat just like everyone else if you want to be comfortable, you need fresh air to stay healthy. Sure you can use a wood stove instead, its been done for thousands of years, but its not comfortable living. My load calculation done by a pro was 50000 Btu for 1800 sq ft, it includes a finished basement in that sq ft #. But heat still cost about 110$ a month a few years ago in winter. With no heat on you would simply freeze, people and apliances cant do it alone healthily, and a space heater is not even heat. You wouldnt want to heat by cooking with a gas stove in a tight house either, you will get sick. Show me a real house, heated to 70f, with a family living happily, healthily in it without a heating system at -20f, or even +40f, it cant be done, and to have your health to.

Reply to
ransley

per

=46rom Wikipedia, the free encyclopedia Jump to: navigation, search

The passivhaus standard combines superinsulation with other techniques and technologies to achieve ultra-low energy use.Superinsulation is an approach to building design, construction, and retrofitting. A superinsulated house is intended to be heated predominantly by intrinsic heat sources (waste heat generated by appliances and the body heat of the occupants), without using passive solar building design techniques or large amounts of thermal mass, and with very small amounts of backup heat. This has been demonstrated to work in very cold climates but requires close attention to construction details in addition to the insulation.

Some may consider that superinsulation is an alternative to passive solar design (although many building designs include features of both with special attention to preventing summer overheating). Superinsulation is one of the ancestors of the passive house approach. A related approach to efficient building design is zero energy building.

There is no set definition of superinsulation, but superinsulated buildings typically include:

Very thick insulation (typically R40 walls and R60 roof) Detailed insulation where walls meet roofs, foundations, and other walls Airtight construction, especially around doors and windows a heat recovery ventilator to provide fresh air No large windows facing any particular direction (unlike passive solar, which uses large windows facing the sun and fewer/smaller windows facing other directions). No large amounts of thermal mass No active or passive solar heat (but may have solar water heating and/ or hot water heat recycling) No conventional heating system, just a small backup heater Nisson & Dutt (1985) suggest that a house might be described as "superinsulated" if the cost of space heating is lower than the cost of water heating.

Contents [hide]

1 History 2 Retrofits 3 Costs and benefits 4 See also 5 References 6 External links
Reply to
hallerb

ater tanks are

upper

I read that, Ive done it, but I could not heat it that way nor would the air quality be safe, I tried to find houses they stated as studys, I cant see a house being heated with apliances and people safely, a heating system is needed for comfort even with passive solar, the sun does not always shine in many areas of the country in winter.

Reply to
ransley

a 'summer

heater tanks are

, upper

it would be near impossible to retrofit super insulation into a existing building, and have it be effective.

details like staggered stud exterior walls matter. so does sealing voids during construction.

however everyone can profit from better insulation.

some homes use heat recovery around drain lines to help warm incoming water.

poured concrete homes, that use rebar reinforced concrete with built in foam insulation, and look like regular homes:) and the exteriors are sprayed with paint containing a realtive of space shuttle tiles add to this. plus these homes are designed to survive a 300 MPH storm. no more wiped out communities

zero energy homes have been built but can cost so much they arent practical.

incidentally a human generates about as much heat as a 100 watt incandescent light bulb. most of us have probably noticed crowded rooms get hot, thats why.

how about building a home in a resort area, and invite the entire home repair group? we can each do our share to warm it:) you can pay the food bill please:)

Reply to
hallerb

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