Facts About Home Cooling

Facts About Home Cooling Energy Savings

When keeping cool means air conditioning, keeping comfortable can often be expensive. Especially since air conditioning can add up to over 11% of your bill. But there are other ways to keep your cool while you save energy and money. This booklet will provide you with information on a variety of cooling systems to help you select the best one for your home. Types of Cooling Systems There are two ways to cool your home conservation measures or active cooling. Conservation or passive measures cool the house without energy-using equipment. For example, shade trees can help keep a home cool by blocking the sun s rays. Awnings or roof overhangs do the same thing. Or you can install insulation, weatherstripping and other measures which also help keep your house cool without electricity. Active cooling, on the other hand, means cooling your home with energy users such as air conditioners. Whole-House Fan A whole-house fan, when combined with other conservation measures, can cool homes in many parts of San Diego County. Mounted in the ceiling, the fan draws in cool, early morning or evening air through windows and doors. And the hot air is forced out through attic vents. Evaporative Coolers An evaporative cooler works by drawing outside air inside through water-soaked pads. Evaporation cools the air which then flows directly into your home or through a duct system. But while evaporative coolers cost less to use than air conditioners, they add moisture to the air. So they re most effective in low-humidity areas such as our desert communities. 2

Central Air Conditioning Central air conditioning is comfortable. But it can also be expensive. The best time to install a central air conditioning system is when your home is being built. You can, however, have it installed after your home has been built. Room Air Conditioners Use room air conditioners when a central air conditioning system is impractical or when you only want to cool certain rooms. When you re buying a new room air conditioner, look for a model with the EnergyStar label. Energy Star-qualified appliances have been approved as smart consumer choices by the Department of Energy (DOE) and the Environmental Protection Agency (EPA). An Energy Star room air conditioner uses 10% less energy than a standard model and can save you $60* over the lifetime of the appliance. *Based on 15 30 cents per kwh Let a qualified air conditioning contractor tell you if your existing forced air heating system can be converted for air conditioning. If so, the installation could cost a lot less than starting from scratch. If you heat with floor or wall furnaces, space heaters, electric resistance ceiling heat, steam or hot water heat, new ductwork must be installed for central air conditioning. It might also be economical to install central heat at the same time. Be sure to get bids from at least three reliable contractors, whether you re having a central air conditioner installed in a new home, or adding it to your existing heating system. Electric Heat Pumps A heat pump is an air conditioner that can be reversed to heat a house as well as cool it. During the summer the heat pump transfers heat from inside air to the outside. A heat pump is an energy-efficient alternative for heating and cooling an all-electric home. 3 4

Selecting the Proper Cooling System Here s how to get the most cost-efficient cooling system. Before you buy, consider these factors: The size of the area to be cooled. The climate of your area. Is it dry or humid? Is it hot for the entire summer or for only a few days? Your home s construction. Brick, wood, stucco, aluminum siding? Is the home two stories or one? Is there an attic? Sun exposure. What direction does the house face? Is it shaded by trees and landscaping? Is the area to be cooled on the sunny side of the house? Windows. How many? Where are they situated in relation to the sun? Wiring. Is there a three-pronged grounded outlet for each room air conditioner? A 208 or 240-volt circuit for a central air conditioner? Insulation. At least R-19* ceiling insulation? *R-19 ceiling insulation alone can cut cooling and heating costs by up to 20%. R stands for resistance to heat flow. (The higher the R number the greater the insulating power.) R-30 insulation is recommended for some areas of San Diego County. Shopping For A Whole-House Fan Whole-house fans are rated in cubic feet per minute, or the amount of air they can move in one minute. If you are planning on install ing a wholehouse fan, you should first determine the volume of your home in cubic feet, excluding the garage, closets and attic. Then look for a fan with a rating that will provide a complete change of air three times an hour. Shopping For An Air Conditioner It s vitally important to get the right fit with a new air conditioner. Too small and it can t do the job. Too big and it will waste energy by repeatedly turning on and off. The amount of heat an air conditioner will remove from a room is its cooling capacity, expressed in BTUs (British thermal units) per hour. The higher the number the greater the cooling capacity. Central air conditioners are sized by ton which equals 12,000 BTUs per hour. Just cooling one room? If you re cooling just one room, a room air conditioner may be more efficient than a central air conditioning unit. When shopping for a new room air conditioner, remember that models with the Energy Star label cost less to operate. 5 6

Important: Removal of this label before consumer purchase is a violation of Federal law ( 42 U.S.C. 6302 ). ENERGY SAVINGS Shopping For An Evaporative Cooler Evaporative coolers are also rated by cubic feet per minute. As with the whole-house fan, calculate the volume of your house in cubic feet. Then divide by two if the home demands considerable cooling. Divide by four if the home is well insulated and shaded. Shopping For A Heat Pump A heat pump usually costs more to install than other electric heating and cooling systems. But its lower operating costs can save the difference in just a few years. Like central and room air conditioning, a heat pump s cooling capacity is measured in BTUs per hour. Installation cost factors include the home s size, insulation, weather-stripping and the heat pump unit itself. Talk to your builder or a dealer to find out if a heat pump is best for you. EnergyGuide Label Based on standard U.S. Government tests Central Air Conditioner Cooling Only Split System XYZ Corporation Model 122345 Compare the Energy Efficiency of this Air Conditioner with Others Before You Buy. This Model s Efficiency 15.2SEER Energy efficiency range of all similar models Least Efficient Most Efficient 10.0 16.9 SEER, the Seasonal Energy Efficiency Ratio, is the measure of energy efficiency for central air conditioners. Central air conditioners with higher SEERs are more energy efficient. This energy rating is based on U.S. Government standard tests of this condenser model combined with the most common coil. The rating may vary slightly with different coils. Federal law requires the seller or installer of this appliance to make available a fact sheet or directory giving further information about the efficiency and operating cost of this equipment. Ask for this information. The EnergyGuide label can be a very valuable resource in helping you select a new appliance. The higher the efficiency rating, the more energy efficient the product and the less it costs to run. Maintenance Tips A properly maintained air conditioner or evaporative cooler will use energy more efficiently than a malfunctioning one. You can use these tips, in addition to the maintenance suggested by the manufacturer, to keep your unit operating efficiently. Replace disposable filters on air conditioners and heat pumps or hose down permanent filters every month or two. Clean lint and dust from outside condenser coils. At the beginning and end of the cooling season, spray coils of air conditioners and heat pumps with a detergent and water solution, then hose them down. Outside evaporative cooler units should be positioned away from direct sunlight. Check the cooler s fiber pads monthly for uniform wetness. If wetness is uneven, clear the distribution tubes of clogs and obstructions with wire. Algae, rust and mineral build-up should be scraped from the water pan to prevent tube clogging. Install new pads before the cooling season. In the fall, drain the water pan and remove rust and scale. A coat of asphalt emulsion on the metal will help prevent rust from plugging the water distribution tubes. If winter freeze-ups are a possibility, water should be drained from the cooler line. Leave the pan drain line open to drain rain and snow. 7 8

Conservation Measures For Cooling Using conservation measures keeps a home cool the natural way...without a big investment in air conditioning or the energy needed to run it. And most of them also help hold down heating costs in winter. The conservation measures are: 1. Insulation 2. Caulking 3. Weather-Stripping 4. Ventilation 5. Shading Insulation Installing insulation is generally the best single step to take to reduce cooling costs. Insulation in ceilings and walls helps keep cool air in while preventing hot air from entering your home. For most of the San Diego area, R-19 is the recommended minimum level of ceiling insulation, R-11 for walls. In some areas R-30 ceiling insulation is more effective. Caulking Caulking is easy, inexpensive and helps keep interiors cool. Caulk the outside of the house where windows and doors meet walls, wherever two different construction materials meet (like around chimneys) and wherever two different parts of the house are joined. There are many easy-to-use caulking products available. Weather-Stripping Cool air can escape from a home through the tiniest cracks around windows and doors. Easy do-it-yourself weather-stripping helps keep cool air in and heat out. For doors there is doorsill and door frame weather-stripping. And window weatherstripping types are also available for double-hung, casement, jalousie and awning windows. Ventilation Summertime temperatures in an unventilated attic can soar to 150 F or more. To keep hot air circulating, an attic should have vents along the eaves to let cool air in, and vents at the peaks of the gables to let hot air out. According to building codes, one square foot of ventilation per 150 square feet of attic space is generally required. 9 10

Turbine ventilators installed near the peak of an attic use wind power to draw hot air out and cool air in through eave vents. Quiet turbine ventilators consume no energy at all. Shading Trees, awnings, solar window shade screens, sun-control window film and just pulling the drapes all help keep you cooler by keeping the sun out. Where To Find Conservation Products Most conservation products are available from local hardware and home-improvement stores. For advice on selecting the proper products, consult a licensed contractor or see your hardware dealer. Energy-Savings Tips Here s how to save money while keeping cool. Set thermostat at 78 F during the day, off at night. Keep air-conditioning vents clear inside an outside the house. Keep windows, doors and fireplace dampers closed when using an air conditioner. Use portable fans to circulate the air. They can keep you cool at a lower cost than using an air conditioner. Turn off the air conditioner when leaving the house. If you re away for only a few hours and want the house to stay cool, turn the air conditioner up 5 to 10 degrees (setback thermostats and timers can be set to cool your home before your return, without running the air conditioner needlessly). or heating system alone to circulate air. Draw blinds and drapes during the warmer parts of the day. Open windows at night and during the cool part of the day. Install reflective films or solar shade screens on windows. Use landscaping, awnings and over hangs for shade. Consider light-colored reflective roofing. We ask that you minimize air conditioner usage on hot summer days to avoid possible shortages of electricity. Especially between the peak hours of 11:00 A.M. and 6:00 P.M. 11 12

For More Information If you d like more energy-saving information, contact SDG&E at 1-800-644-6133, or by e-mail at esc@semprautilities.com. You can also visit our website at sdge.com. Notes: 13 14

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