RISMEDIA, July 8, 2009-(MCT)-Q: I thought I was operating our air conditioner efficiently until a neighbor came over to our house and told me he just read in your column that I shouldn’t leave the “fan setting” running all the time on our thermostat like I usually do. Now I’m wondering if I’m using the air conditioner properly or not. It does seem our house never cools off in hot weather. What tips do you have for staying cooler?
A: I’ll start by repeating something I wrote about this recently and that keeps coming up often because it seems to make sense doing it the wrong way. When you keep the thermostat fan set “on” all the time, you might think you’ll constantly get cooling breezes in the house. What’s really happening is that the blower is constantly pushing air through the ductwork even when the compressor is in its “off” cycle. When the compressor is on, it helps get moisture out of the house, but when the compressor is off, the blowing fan that you’ve got set to run brings that moisture back indoors. As a result, your cooling strategy isn’t giving you cool breezes to enjoy, but it is instead running up the home’s humidity levels and your monthly utility bills.
When’s the last time you changed the filter in the system? Unless you’ve got a filter that calls for replacement on a specific schedule like once a year or some other extended time period, the typical inexpensive filter sold in building supply and hardware stores really ought to be replaced every month. They need to be kept clean so the air can flow through them. A filter that gets clogged by dust and dirt can increase your energy costs, keep your home uncomfortable, and actually cause damage to the cooling equipment. This is a very small expense and an easy job to do, and a simple monthly maintenance task that can keep your cooling and heating equipment operating properly for many years.
I’ve been giving lots of talks lately to homeowners, and hear the same comments over and over again. Many people say they keep their thermostat on the coldest setting in summer since it just doesn’t get their home comfortable when it’s near the recommended summer setting of 78 degrees. These same people usually also complain about very high energy bills. A potential problem here could be miscalibrated thermostats. I’ve seen research studies that have found thermostats to be calibrated improperly in a number of homes studied, often showing a difference in performance of several degrees from what they are reading. If you set your home thermostat to energy-efficient levels (78 degrees or so in summer, around 68 degrees in winter), and the home seems to be much warmer or cooler than what it should be, rest a thermometer on top of the thermostat and see how accurate it really is. If your setting of 78 actually turns out to be 72, then you’re simply wasting money.
I often have people tell me that they don’t want to raise their thermostat setting in summer or lower it in winter when their house is empty for several hours since it will use a lot of energy to get it back to their desired setting. Again, this is a misconception, since the savings from raising the setting on an empty home in summer, for example, will outweigh the costs of cooling the home back down to the desired temperature.
Finally, when was the last time you had your air conditioner serviced to assure it had the proper refrigerant level and everything was working as it should? Most people make sure their cars have regular maintenance every 5,000 miles or so, but I don’t hear too often from homeowners who have regularly scheduled maintenance on their home’s cooling and heating equipment. An air-conditioner refrigerant level that is either too high or too low will not only affect the system’s performance, but can also cause costly mechanical damage and increase its energy use.
Ken Sheinkopf is a communications specialist with the American Solar Energy Society (www.ases.org). Send your energy questions to askken(AT)ases.org.
©2009, McClatchy-Tribune Information Services.
