Backup Generator size

[GarthH]

I've been considering a backup generator for emergency use. I would like to run our house with a minimun usuage like the fridge, a few lights, and electric heat in a few rooms (we have a separate electric heater in each room). Could anyone recommend an appropriate size in Kv's?

Thanks

Garth

 

[Shimon]

Since you have electric heat I would recommend an 8kw generator. It really depends on how many heaters and how many watts each heater is. How about hot water heater? Well water pumps? Electric stove? If you have any of those you may want something a little larger.

Will this be a portable or permanent or PTO gen?

 

[Cottonhawk]

Where you live can get to be very cold and it can be much much colder if your power is out! 8 kw should be enough if you keep low load, but I'd go higher so you have some flexibility.
We have just installed a propane powered 20 kw ONAN generator with automatic switch. It will power the entire house when the power is down and all I have to worry about is that I have enough propane in the tank.

 

[Mike_Lipke]

Electric baseboard heat is usually 250 watts/foot. That means every 4 feet needs a kilowatt.
If that is all you were going to run, then 8kw might be fine. But you have a refrigerator that prolly takes at least 1.5kw to start, .6 to run.

8kw will work, for the fridge and lights, but you will have to run the heaters one or two at a time, or when that fridge compressor tries to start, it can burn out. Big$$.

How putzy do you want to be when the power is out?
If you are on a well, that gets even more interesting.

 

[kennyd]

I installed a automatic 15kw Generac at my house 2 years ago...
But we need more info to help you.

There are lots of calculators online like THIS one that also can help you.

 

[randy41]

does that calculator assume you run all the power consuming things at the same time?

 

[salopez]

I believe that calculator adds everything up.

I went with a small 6.5 kw diesel for my condo. My switch allows me to run what I need when I need it...Ie I turn the fridge off to run the heat....

 

[kenmac]

My opinion,I wouldn't install any less than a 10 kw Might even go with 15 kw

 

[BobRip]

Heat is a very inefficient thing to run on a generator. Could you get a kerosene heat and a smaller generator. With a generator fuel becomes the limiting factor. At 1/2 to 1 gallon an hour (depending on load and generator size), you have to store a lot of fuel to run it even 12 hours a day. The kerosene heater is at least three times more efficient that a generator at making heat on a per gallon of fuel basis. A four kilowatt generator and a kerosene heater (or two) would get you by pretty well for less money and less fuel. If you are on a well, that is a whole different story. My well would not start reliably on anything less than an 8KW generator. This amount depends a lot on the depth of the well.

When it's cold outside, put you food in an ice chest that is outside and shutdown the refrigator.

Do you have a gas or oil furnace? They take much less power to run than even a small electric heater.

 

[gordon21]

Bare bones usage will require a 5500-6500 watt model for approx $600 plus extension cords.

Do NOT tie into the breaker box or backfeed through an outlet unless you know exactly how to isolate the system from the power company.

Alternating loads is the key to making a small unit acceptable. Run the water heater for only 2 hours and the water will stay hot for at least 12 more hours. Once you turn it off, then use those same watts to run the A/C or heat for a few hours.

You can usually keep a few lights, the refrigerator, a TV and the satelite dish running non-stop. They will need only 600-700 watts combined. The other 5000 watts are the ones you need for the big items.

If your budget is for $1200 or more, then you can get a lot more items running at once. A small whole house system with automatic starting will begin at $4000

$600 is the cheapest way that will provide any type of acceptable results.