# Calculate power needs before buying generator

Q. There have been some power outages, so I am considering getting a backup generator. What are the best types to get to take care of the entire house? Can I run it continuously to lower my electric bills?

With most families dependent on electricity for almost every activity these days, backup generators are becoming more common for residential properties. In addition to loss of electricity during storms, there are more brownouts during summertime because the grid is stressed on hot afternoons.

Backup generators for houses are called standby models because they are supposed to come on automatically only when the electricity from the utility grid fails. They are designed to run for a relatively short time until the power is back on. This may be several days at times.

If you tried to run a standby generator continuously to eliminate the need for the utility company’s electricity, the unit probably would not last long and would require much maintenance. Also, the cost for the fuel to operate it continuously would be much greater than your current electric bills.

You must decide what you mean by powering the entire house in order to determine the size of backup generator you will need. There are essential items such as the refrigerator, stove and lights. Other items, such as air-conditioning, washing and drying clothes, vacuum cleaner or system, may not be needed during the power outage.

A 12-kilowatt generator generally can provide power for a family of four. If you can eliminate nonessentials, a less expensive, smaller unit might be adequate and the fuel costs to operate it might be lower.

To get a rough idea of the size generator you will need, list the electric items you most want to use. Add up the wattages for all of these items. Equipment with a motor often requires more electric current at start-up, so increase the capacity somewhat. The contractor/installer can also advise you on the proper size.

For convenience and safety (for both your family and the utility company’s workers), install an automatic transfer switch. It detects a loss of power and voltage drops, known as a brownout. It automatically disconnects from the utility grid and starts the generator. It also runs the generator periodically to test if it is working properly.

If you have natural gas available at your house, this is the best fuel to power a backup generator. It runs cleanly and is the least expensive. Propane also runs cleanly, but it costs more than natural gas and requires a tank. Natural gas and propane engines require little regular maintenance.

A diesel engine-powered generator also requires a fuel tank, and the shelf life of the diesel fuel is only a couple of years.

The following companies offer backup standby generators: Baldor, www.baldor.com; Coleman Powermate, www.powermate.com; Cummins Onan, www.cumminsonan.com; Generac Power Systems, www.generac.com; and Kohler Power Systems, www.kohlergenerators.com.

Q. We do not cover our central air conditioner over winter and there is some debris, leaves, etc. down inside of the outdoor unit. Is it important to clean this out to improve its efficiency?

It never hurts to keep it somewhat clean inside, but a little debris on the base is usually not a problem for efficiency. It is more important to keep the outside clean so air flow through it is not impeded.

If you do pull off the side cover to clean out the debris, make sure to fit it back on perfectly and tighten all the screws. If it is not tight, the fan may draw air in through gaps instead of through the coils as it should.

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This affects comments on all stories.

The Charlotte Observer welcomes your comments on news of the day. The more voices engaged in conversation, the better for us all, but do keep it civil. Please refrain from profanity, obscenity, spam, name-calling or attacking others for their views.

Have a news tip? You can send it to a local news editor; email local@charlotteobserver.com to send us your tip - or - consider joining the Public Insight Network and become a source for The Charlotte Observer.