Home Improvement : Generator Keeps Home Humming
QUESTION: We sometimes have electric power outages. To keep my furnace blower, sump pump, refrigerator, freezer, lights, etc. running, I plan to buy an emergency generator. What are available and are they efficient?
ANSWER: Electric utility power outages can be a problem. Even if you have a gas forced-air heating system, without electricity for the blower, there is no heat. Extended power outages can allow frozen foods to thaw and spoil. Home security systems often stop functioning.
The most effective and convenient types of home emergency standby generators are 8 to 10 kilowatt (KW) output systems. These systems are placed outside your house and look very similar to an outdoor central air-conditioner unit. You can get systems as large as 20 KW output.
Inside your house, near your existing circuit breaker panel, you locate an automatic transfer switch. The electronic circuitry senses when the utility power goes off or the voltage is too low. Automatically it starts the generator motor and switches your house power from the utility lines to your own generator.
Within less than a minute, you have electric power again during a utility power outage. It also starts (exercises) the generator motor once a week for a short period to make sure it is operating properly. Manual transfer switches are available that require you to physically throw the switch.
These small 8 to 10 KW systems utilize small air-cooled or water-cooled engines. These are similar to motorcycle or small automobile engines and are designed to operate on natural gas, bottled gas or gasoline.
The home-sized generators are efficient. When powered on natural gas, the fuel cost alone is equivalent to about 12 cents per kilowatt-hour of electricity produced. The only additional operating cost is generally changing the engine oil once a year.
In order to determine the size of the emergency generator you need, add up the watts used by the appliances and lights you want to keep running during a power outage. The wattage usage is usually shown somewhere on the products’ nameplates.
For example, a furnace blower uses about 1,000 watts of electricity, color TV 300 watts, gas dryer 400 watts, freezer 500 watts, microwave oven 800 watts.
You can write to me at the address below for Utility Bills Update No. 015 showing names, addresses and telephone numbers of manufacturers of automatic emergency generators, product information and specifications, and a chart showing the wattage usage of common appliances. Please include $1.50 and a self-addressed stamped business-size envelope.
Calculating Levels of Heat Loss Difficult
Q: I want to determine how much heat is gained and lost from my house through my windows as compared to my walls. I am trying to decide if I should get replacement windows.
A: It is a very involved calculation to determine the heat loss or gain through windows. There are many factors including the glass type, shading, airtightness, frame materials, orientation to the sun, etc. Don’t just use the manufacturer’s rated insulation R-value of the glass to compare that to your wall R-value.
Considering the substantial investment in replacement windows, you should consider employing the services of a qualified energy auditor for an analysis. It will be $100 well spent.
Letters and questions to Dulley, a Cincinnati-based engineering consultant, may be sent to James Dulley, Los Angeles Times, 6906 Royalgreen Drive, Cincinnati, Ohio 45244.
