Q. Our electric rates are high and we have power outages during storms. I want a backup generator for the entire house. What type and size is best and can I use it nonstop instead of the utility's power?
To answer your last question first, a standby generator, even a large one, is not designed to be used continuously so you can disconnect your home from the electric utility. It is designed to operate for only relatively short periods during power outages. Also, electric generation costs from a standby generator are greater than your electric rate.
No matter what size (generation capacity in kw - kilowatts) whole-house generator you select, it is best to also install an ATS (automatic transfer switch). This control switch senses when the utility's electric power stops or the voltage is too low during a brownout (often on a hot summer afternoon).
When the ATS kicks in, it temporarily disconnects your house from the utility grid and starts the generator. This can take a short period to be up to full power. Without an ATS, you would have to do this manually or the utility lineman may get shocked from your generator.
The size of standby generator you need depends upon how many electric items you want to operate during a power outage. A 12-kw generator will handle a typical family's power needs. If you can get by without air-conditioning or hot water for a while, this will allow you to install a smaller, less expensive generator.
Sum the wattages of all the electric items you think you need. The wattage of various appliances are listed on each appliance nameplate. Keep in mind though, many appliances with motors require greater starting wattages than the continuous usage listed on the nameplate. For example, a refrigerator using 700 watts may require up to 1,500 watts each time the compressor starts.
Most people select a natural gas standby generator if gas is available. It is clean burning and does not require a storage tank. If there is a natural disaster though, such as an earthquake, the supply may be stopped.
Propane is another common fuel. It burns cleanly similar to gas. Since the tank is on your property, the supply cannot be interrupted. It is more expensive than gas and it requires a tank. Diesel fuel is safe (less flammable) and easy to obtain. It requires an expensive tank and the shelf life of the diesel fuel is less than two years.
The following companies offer backup standby generators: Baldor, Coleman Powermate, Cummins Onan, Generac Power Systems and Kohler Power Systems.
2 fans will work together
Q.I want to install a whole-house fan this spring to keep my house cool inexpensively. I already have an attic vent fan to cool the attic. Will this attic vent fan make the whole-house fan less effective?
They should work fine together. The whole-house fan will generally be used in the morning and evening when the outdoor temperature is lower. During these periods, the attic vent fan probably won't be running anyway.
Even when both fans are running, they will complement each other. The whole-house fan will create a slight positive pressure in the attic. This positive pressure will increase the air flow through the attic vent fan.