Category : general , 2 years ago
It’s blazing hot, but after opening your last utility bill, you don’t dare turn down the thermostat. How to keep your house as cool as possible during these hot summer months? Trying to remember the conventional wisdom but not quite sure how it goes? Those window fans, for example, should they be placed to draw air in or out? Upwind or downwind of the dwelling? And what about windows, shades, and awnings? Are windows on the North side of the house better left closed or open during the day? Are awnings better than shades? A variety of relatively simple measures can help you drop your thermostat’s mercury without raising your utility bills bottom line. Here are some general tips that you can do to cool your house.
1. Arrange furniture and drapes so they don’t restrict airflow from registers. When cooled air is delivered to your rooms, it should move freely.
2. Keep room air moving by utilizing a whole-house fan or ceiling fans. Another option is to circulate air using the “Fan Only” setting on your heating/cooling system’s thermostat. By keeping the air moving, you will feel comfortable in a room that is 2 or 3 degrees warmer than a still room; every degree you raise your thermostat’s set point will save you about 2 percent on your energy bill.
3. Reduce your home’s heat gain by pulling drapes or shades–or installing awnings–over sun-facing windows. Installing an awning is a inexpensive way to reduce solar heat gain through windows. Also explore the possibility of installing inexpensive heat-reflecting film on those windows.
4. Increase your air conditioners efficiency by cleaning or replacing your furnace or air handler filters according to the manufacturers recommendations. Change all filters that serve the air conditioner at least twice a year to ensure maximum efficiency.
5. Install a programmable thermostat if your system doesn’t have one—and learn to use it properly. This will give you precise control over exactly when cooling will be delivered. Raise the thermostat’s set point a few degrees when you’ll be at work; if you’ll be gone for two days or more, turn off the air conditioner until you return.
6. Reduce humidity inside your home, because an air conditioner must work hard to remove moisture from the air. Minimize mid-day washing and drying clothes, showering, and cooking. Another option is to turn on ventilating fans, but be sure to turn them off when you’re finished so that they don’t extract cooled air unnecessarily from the house.
7. Weatherize your home to reduce the loss of conditioned air. Employ caulk, weather stripping, and insulation to cut back on the movement of air from inside to out—and vice versa.
8. Consider installing dampers in ductwork to restrict the flow of cooled air to rooms that you rarely use. Talk with an air conditioning contractor about this. You can also close doors or registers in those rooms, but ask a professional about this to be sure it won’t affect your system’s efficiency.
Motorized damper for a zoned system is inserted into ductwork and controlled by small motor to allow the flow of cooled (or heated) air.
9. Update your air conditioner if it’s old. Though this is not a low-cost solution, over-the-hill equipment may be using far more energy than necessary to cool your home. See the free Central Air Conditioners Buyer’s Guide for more about how to select an efficient, high quality air conditioner.
Efficient cooling saves money, energy, and the quality of our lives
1. Reduce the cooling load by employing cost-effective conservation measures. Provide effective shade for east and west windows. When possible, delay heat-generating activities such as dishwashing until evening on hot days.
2. Over most of the cooling season, keep the house closed tight during the day. Don’t let in unwanted heat and humidity. Ventilate at night either naturally or with fans.
3. You can help get rid of unwanted heat through ventilation if the temperature of the incoming air is 77 F or lower. (This strategy works most effectively at night and on cooler days.) Window fans for ventilation are a good option if used properly. They should be located on the downwind side of the house facing out. A window should be open in each room. Interior doors must remain open to allow air flow.
4. Use ceiling fans to increase comfort levels at higher thermostat settings. The standard human comfort range for light clothing in the summer is between 72 F and 78 F. To extend the comfort range to 82 F, you need a breeze of about 2.5 ft/sec or 1.7 mph. A sow-turning ceiling-mounted paddle fan can easily provide this air flow.
5. In hot climates, plant shade trees around the house. Don’t plant trees on the South if you want to benefit from passive solar heating in the winter.
6. If you have an older central air conditioner, consider replacing the outdoor compressor with a modern, high-efficiency unit. Make sure that it is properly matched to the indoor unit.
7. If buying a new air conditioner, be sure that it is properly sized. Get assistance from an energy auditor or air conditioning contractor.
8. Buy a high-efficiency air conditioner: for room air conditioners, the energy efficiency ratio (EER) rating should be above 10; for central air conditioners, look for a seasonal energy efficiency ratio (SEER) rating above 12.
9. In hot, humid climates, make sure that the air conditioner you buy will adequately get rid of high humidity. Models with variable or multi-speed blowers are generally best. Try to keep moisture sources out of the house.
10. Try not to use a dehumidifier at the same time your air conditioner is operating. The dehumidifier will increase the cooling load and force the air conditioner to work harder.
11. Seal all air conditioner ducts, and insulate ducts that run through unheated basements, crawl spaces, and attics.
12. Keep the thermostat set at 78 degrees F or higher if using ceiling fans. Don’t air-condition unused rooms.
13. Maintain your air conditioners properly to maximize efficiency.
Warm Weather Window Solutions
1. Install white window shades or mini-blinds. Mini-blinds can reduce solar heat gain by 40-50 percent.
2. Close south and west-facing curtains during the day for any window that gets direct sunlight. Keep these windows closed, too.
3. Install awnings on south-facing windows, where there’s insufficient roof overhang to provide shade.
4. Hang tightly woven screens or bamboo shades outside the window during the summer to stop 60 to 80 percent of the sun’s heat from getting to the windows.
5. Apply low-e films.
6. Consider exotic infills in your windows, a new technology that fills the space between panes with krypton or argon, gasses that have lower conductivity than air, and which boost R-values.
Tips for your A/C
1. Provide shade for your room A/C, or the outside half of your central A/C if at all possible. This will increase the unit’s efficiency by 5 percent to 10 percent.
2. Clean your A/C’s air filter every month during cooling season. Normal dust build-up can reduce air flow by 1 percent per week.
3. Turn off your A/C when you leave for more than an hour.
4. Several studies have found that most central air conditioning systems are oversized by 50 percent or more.