Ek's Home   |   Forum   |   Chat   |   Electrical Links   |  





Subject - Electric Heat
teds46 How can I calculate size of electric heat needed for a residential dwelling
JimmyDee Back in the late 60s I took a class that taught me exactly how to do it. It is a complicated process by which you determine the heat loss in BTUs for everything. Ceiling, floors, walls, doors, windows, and air infiltration. You have to know the lowest expected outside temperature and subtract that from 65°F. If I remember correctly my biggest room was the living room (12'x18') and it required 4200 watts. Design was for -10°F. (Ceiling cable heat, it was the greatest but couldn't afford to use it)
I know this doesn't help but I'll check on Google and see if I can find something.
JimmyDee http://www.heatersplus.com/heat-req.pdf
Try this link. Has a lot of stuff in it.
Jim
lctrc789 Correct me if I am wrong on this one but I was always told that about 1 watt per 1 cu.ft of area.Then add 1 watt per every door and window opening for the same.
It has been a long time since I have doine this"
Say a 60 X 30 home with door and window openings that calcualte to about 2000 more cu. ft. that would be about 16,400 watts of heat or 70 amp electric furnace. Always if you live in Zone 1 2 add 30 % more for a total of 21,320 watts or a 90 amp furnace.
Baseboard heat and cable heat was figured in each room the same way total cu. ft. and total watts at 1 watt per cu. ft.
The further up north of course the more % you add but zone 1 and 2 were up north as far as you could go to the canadian border.
Hope this has made some sense.
JimmyDee
quote:
Originally posted by lctrc789

Correct me if I am wrong on this one but I was always told that about 1 watt per 1 cu.ft of area.Then add 1 watt per every door and window opening for the same.
It has been a long time since I have doing this"
Say a 60 X 30 home with door and window openings that calculate to about 2000 more cu. ft. that would be about 16,400 watts of heat or 70 amp electric furnace. Always if you live in Zone 1 2 add 30 % more for a total of 21,320 watts or a 90 amp furnace.
Baseboard heat and cable heat was figured in each room the same way total cu. ft. and total watts at 1 watt per cu. ft.
The further up north of course the more % you add but zone 1 and 2 were up north as far as you could go to the Canadian border.
Hope this has made some sense.


I think you may be close with this figure because if my memory serves me correctly, 1 watt = about 3.5 BTUs (actually 3412.142) of heat so your example would give you about 75,000 BTUs for our northern area which is about right. You need to remember there are no flue losses for electric heat so it would be like putting in 90k to 100k BTU furnace.
Jim