Apartment Building Going To Electric Baseboard Heat

[Walters Powerhouse]

I wanted to get some different opinions on installing electric baseboard heat in a apartment building with 4 apartments. two apartments are larger 770 square feet each. The other two apartments are smaller and only have about 477 square feet. My city inspector request 10watts per sq foot with electric baseboard heat. Each apartment is ran off a 100 amp Westinghouse 8 space Panel board. It says on the cover accepts breakers br,bo,bq,brwh,brsw and something that looks like gfcb which I'm not sure about. the two small apartments have 3 spaces left in the panel board. One of the two large apartments panel's is full and the other apartment has only two spaces left.
So with the small apartments i came up with 477 feet x 10 =4770
4770/240=19.875 amps x 1.25 (for heat)=24.84amps so one 30 amp cir for each of the small apartments installed entirely of 10# wire.
For the large apartments i came up with 40.10amp I assume that would they would take two 30 amp cir to run all the electric baseboard heat in each of the apartments. I'm having trouble with determining if i can install piggy back breakers in these panels to get out of doing a upgrade on the service.

Thanks for any help you can throw my way.

 

[__dan]

As an electrician, the first thing I would look at is if utility natural gas, methane, is available in the building or in the street. If gas is availabe for the building, I would insist on gas hydronic. I would not consider electric except as a last resort.

If it has to be electric, for four units you want to do a load calc. With no gas your other major loads are also electric, DHW, major appliances. Chances are good the load calc shows a new riser, new service, with the added WAG 22 kw of electric baseboard.

Working backwards from the breakers spaces available, one circuit in #10 is going to be too tough to run in and out of the thermostats and 4 baseboards (labor issue not loading issue). Two circuits in #12 is more likely, two baseboards / circuit WAG, so again, likely new panels are the smart bet.

 

[SmithBuilt]

Regarding the piggy back breakers. It is up to the panel manufacture and normally stated on the panel's instructions. I doubt if older Westinghouse panels had a provision for them.


I stand a little differently from Dan. As an electrician I would be pushing for the upgrade. It might actually be a less expensive install than gas. Plus, big plus you could be making the money.


Not to mention who knows what gas prices will be in the future. At least electric rates are regulated.

 

[Joe Villani]

Electric Baseboard Heat

Electric Baseboard Heat

I don't how a municipality can state they want 10 watts per square foot for the electric heat calculation.

If you can, get it in writing.

Depending on the condition of the building the 10 watts per square foot can be too small, or too large.

A heat loss calculation is the best way to go, and yes I have used the 10watts a square foot method many times in the past, but I feel the inspector is overstepping his bounds.

As far as the panels go, do the math, and you'll see what needs upgrading. The individual units may be fine and only the service entrance will need increasing.

Joe