Is 100 Amp Service Enough To Heat House

Volition your home inspector tell yous if your electric service is also small?

While it goes beyond the scope of a home inspection to perform load calculations, occasionally I'll do a rough adding if I get concerned that an electrical service is also small-scale for a business firm. If the service size from my crude adding comes up too close to the actual service size, I'll recommend having an electrician perform an official load calculation… and I think I've done this twice. Ever.

At nearly every habitation inspection, I find one of ii things: either the electric service is outdated and obviously too small, such as the 30 amp service pictured at right, or the service has been upgraded or over-sized and is plenty big enough for the home. I don't find much in-between those two.

I got to thinking about this while inspecting a 3,600 sf house in Plymouth for an erstwhile friend from loftier schoolhouse. This abode had a 100 amp electric service, which seemed too small for that size of a house. I considered recommending an electrician to do a load calculation on the house, merely I first plugged in a few numbers at an online load figurer – http://wireyourownhouse.com/tools/housecalc.html .

I didn't have all of the exact numbers that I needed, and so I guessed on a agglomeration of them, such as the VA ratings on the garage door openers, garbage disposer, dishwasher, and microwave. I put in 1800 VA for each i of these, which is certainly way too high, merely it makes me experience better about guessing – at least I'chiliad not guessing on the low side.

This home was heated with a gas furnace, had a gas clothes dryer, a gas water heater, and a gas oven. The just major 240 volt appliance at this dwelling house was the air conditioner. This is pretty common for a home in Minnesota.

Tin yous guess what the calculated service size was?68 Amps.

Granted, my calculation probably wasn't perfect, and I'm not sure that this online load calculator was completely accurate, merely this was enough to make me not worry about the service size. When I took an electrical inspection class many years ago, nosotros had to perform a lot of load calculations for fictional houses, and I learned enough to know that if most of the major appliances are gas, a 100 amp service is probably plenty enough.

I invite y'all to plug in the numbers from your own home at the online load reckoner that I linked to higher up – you might be surprised at how pocket-size of a service yous could really go away with. For the record though, the smallest allowable service for a new dwelling house today is 100 amps.

Reuben Saltzman, Structure Tech Home Inspections – Electronic mail – Plymouth Home Inspector