Rocky Mountain Institute’s Home Energy Briefs #3 SPACE COOLING

The 2004 edition of this Brief is made possible with generous support by Stonyfield Farm (www.stonyfield.com), the National Association of Realtors (www.realtor.org), the Durst Organization Inc. (www.durst.org), and Deborah Reich.

Space cooling and heating inside the home, and then, if PASSIVE COOLING account for 45 percent of total additional cooling is still needed, MEASURES home energy use and cost a typi- take steps to increase the effi- You can protect your home from cal family $677 a year. Depending ciency of the cooling equipment heat gain by implementing a num- on where you live, your energy and/or buy new and more efficient ber of passive cooling measures. bill could be dominated by cooling equipment. In practice, passive cooling means energy use in the summer, heating creating an environment that con- energy use in the winter, or both. This Brief will cover the trols and lowers the amount of Space cooling alone typically following topics: heat gain in the home without accounts for 13 percent of total • Heat gain: using electrical equipment such energy use, costing the home- How heat enters the home; as air conditioners or fans. The owner $197 per year. For states in U.S. Department of Energy (DOE) hotter climates, space cooling can • Passive cooling methods: How to minimize heat gain in the estimates that passive cooling account for over 20 percent of home; and measures can reduce energy bills total energy use and cost more by up to 40 percent.2 You should 1 • Space cooling systems: than $350 per year. always investigate such measures Fans, evaporative coolers, heat pumps, and air conditioners. before investing in new cooling A well-insulated and tightly equipment. Reducing your cooling sealed home that uses the natural load allows you to purchase a movement of heat and air to main- HEAT GAIN smaller and cheaper cooling sys- tain comfortable indoor tempera- tem. The most effective passive tures can reduce cooling costs by Heat naturally flows from warmer spaces to cooler ones until the cooling measures, in order of up to 50 percent while also saving increasing cost, are: on heating bills (see Home Energy temperatures in and between the two spaces are equal. In the Brief No. 4: Space Heating). The • Natural ventilation. By opening space cooling philosophy is to summer, the home warms up by windows at night, you can cool first minimize the amount of heat absorbing heat from outside the home by flushing out heat that enters the home as well as through its building envelope and and moisture that accumulates during the day; the amount that is generated by generating heat from within. Heat is absorbed primarily through windows, exterior walls, glass • The minimization of indoor heat generation. For example, using doors, skylights, the roof, ceilings, Other titles in Rocky Mountain Institute’s energy-efficient light bulbs, Home Energy Briefs include: attic, and foundation. Heat is gen- reducing hot water use, using erated primarily by appliances, No. 1 Building Envelope smaller and more efficient appli- No. 2 Lighting lights, and other equipment (see No. 3 Space Cooling Home Energy Brief No. 1: Building No. 4 Space Heating Envelope for more detailed infor- No. 5 Water Heating For additional information, mation on heat gains and losses as well as a downloadable No. 6 Cleaning Appliances in the home). version of this document, No. 7 Electronics please see our website: No. 8 Kitchen Appliances www.rmi.org No. 9 Whole System Design This document was last updated: 12/3/04 2

RMI’s Briefs: Home Energy ances, and scheduling heat-pro- SPACE COOLING Portable fans: The main types of ducing tasks—like clothes dry- SYSTEMS portable fans include table fans, ing—for cooler hours of the day; If you have implemented the pas- floor fans, and window fans. • Weatherization. Caulking, sive cooling measures discussed Depending on the type, quality, and sealing, and weatherstripping all above and still require supplemen- size, cost varies from under $10 to

#3 Space Cooling building envelope seams, cracks, tary cooling, there are many over $200. A small table fan will and openings reduces heating mechanical cooling systems that provide on-the-spot cooling, while and cooling energy require- larger fans such as window and ments; you can choose from. Different systems are appropriate for differ- floor fans can—if placed in or near • Insulation. Insulating your home ent budgets and climates. This a window on the cooler side of the with foam, organic batting (cot- section discusses each of these home—significantly aid in cross ton and sheep wool, cellulose, systems and describes how they ventilation. Using two window fans and slag wool) or heat-reflecting work, their cooling capacities, can often be better than using one. foil reduces heat conduction For example, use one fan to pull in into your living space; efficiencies, sizing, and costs. The systems are generally listed in cool air in a lower-floor window • Window shading and glazing. order of increasing cost, consider- and another to blow warm air out Solar radiation passing through ing both initial and operating costs. an upper-floor window. windows can contribute 20 per- When contemplating buying a cent of heat gain in hot, humid new cooling system, consider the Ceiling fans: Ceiling fans can keep climates.3 Window shading options in the following order: a room comfortable by providing devices and glazing technology airflow throughout a room. In mod- minimize heat gain while trans- mitting daylight, which reduces Fans erate climates, ceiling fans can provide enough cooling to com- electrical lighting needs; There are three main types of fans pletely replace an air conditioning that aid both in cooling and venti- • Roof whitening and attic ventil- system. For hotter climates, using lating the home: portable fans, ation. These are two effective ceiling fans in conjunction with air ceiling fans, and whole-house measures to reduce heat gain by conditioning will allow you to raise either reflecting heat away from fans. All of these fans operate in a the thermostat by as much as 4ºF, the roof or flushing heat out similar fashion: they move air thereby saving energy while main- through the attic; and throughout the home and increase taining comfort.4 Ceiling fans are the amount of heat that is removed • Trees and landscaping. Planting considered low-energy con- from the home and the objects and broad, leafy shade trees that sumers, because they typically use people within it. Fans also bring block the sun will reduce the about the same amount of energy amount of solar radiation fresh air into the home and can as a 100-watt light bulb. They can absorbed by the house. help remove indoor air pollutants cost between $25 and $250 to buy (i.e., dust, fumes, moisture, etc.). See Home Energy Brief No. 1: and $100 to $3,300 to install. Building Envelope for detailed Table 1: What size ceiling fan When purchasing a new ceiling information on key passive cooling 5 does your home need? fan, look for ceiling fans with an measures. ® Minimum fan Energy Star Label. They typically Room area diameter (sq. ft) use 20 to 50 percent less energy (inches) and save about $25 per year in Fans can be noisy! 100 36 energy costs. They also can be nearly 150 42 inaudible, so shop around Whole house fans: Whole house and make sure you check 225 48 fans can often be the most cost- the noise level of a fan 375 52 effective way of cooling a home in before purchasing it. A moderate climates. They provide quiet fan will have a noise 400+ Two fans good air circulation and aid in rating of 1.5 sones or less Source: Minnesota Department of Commerce Home while a noisy fan will have a Cooling fact sheet, p. 2. www.state.mn.us/cgi-bin/ cooling by pulling cool, fresh air in portal/mn/jsp/content.do?action=doc_contentlist&sub- rating higher than 4. channel=-536881511&programid=536885406&sc3= from lower-floor windows; this air null&sc2=null&id=-536881350&agency=Commerce is then typically vented through the 3

tilating power your home needs ature. A fan then circulates the RMI’s Briefs: Home Energy Figure 1: Whole house fan system6 would be: 16,000 ft 3 x (30 to 60) ÷ 60 moist, cool air into the home and = 8,000 to 16,000 cubic feet per pushes warmer air out through minute. The recommended air open windows. Note: windows or changes per hour depend on a outside vents need to be open in

number of things, including your order for an evaporative cooler #3 Space Cooling climate and floorplan. To get a to function properly. more exact number for your home and climate, contact a local There are three main types of Source: Adapted from DOE, “Cooling your Home with Fans and Ventilation,” p. 5 professional. evaporative coolers: portable units also known as “swamp coolers,” roof. They typically cost around Drawbacks: Whole-house fans fixed room units, and whole-house $500 to install and have very low can be a source of heat loss in the systems. A portable swamp cooler operating costs (~$0.01–0.05 per winter and can cause backdrafting is typically a small unit that can hour of use). Energy Star-rated from combustion appliances in the provide adequate cooling for a whole-house fans do exist and use home. To prevent heat loss, make small room or a part of a room. 65 percent less energy than stan- sure that the fan is sealed well and Fixed room units are mounted in dard models. They also typically an insulated cover is placed over the wall or in a window and can make less noise and last longer. it during the winter. Backdrafting provide enough cooling for the occurs when there is not enough entire room. Whole-house systems Sizing: This depends on how much ventilation in the home (i.e., lower- include direct, indirect, or com- ventilating power your home floor windows are not open). This bined direct/indirect systems that needs, which ultimately depends can pull gases from combustion are typically ducted. They provide on the size of your home. Once you appliances (e.g., water heater, cooling for the main living area of know the ventilating power, you chimney, wood stoves, etc.) into the home and/or each individual can choose a fan that will provide the rest of the home, which can be room. The cheap and high mainte- it. DOE recommends using the fol- extremely dangerous. To prevent nance swamp coolers of yesterday lowing formula to figure this out: this, make sure that there is are a world apart from modern enough ventilation in the home by evaporative cooling systems. New Ventilating power, ft 3/min or opening windows, especially on systems are more efficient, use cfm = Volume of home × (30 to 60 lower floors, when the fan is on. To less water, and provide years of air changes per hour) ÷ 60 be on the safe side, you might not trouble-free service to cool and want to install a whole-house fan clean the air. Given that the tech- For example, if the volume of your unless these appliances have a nology has certainly changed, the home is 16,000 cubic feet, the ven- direct air-intake line from outside. perception of evaporative cooling systems will need to be updated; ® What is Energy Star ? Evaporative coolers today they are a high-performance Energy Star® is an EPA- In dry climates, evaporative cool- alternative to conventional air backed program that sets conditioning systems. strict efficiency guidelines ers typically use less than one for home products. For quarter as much energy as con- products that meet these ventional air conditioners and can Figure 2: Schematic of how an guidelines, an Energy Star save hundreds of dollars a year evaporative cooler works label, shown below, is often on home cooling costs. They are 75% placed on the product. Look effective pad also less polluting since they don’t evaporative cooler for this label on the product or in its specifications to require the use of toxic chloro- 70º fluorocarbons (CFCs) or other air 100º ensure you are purchasing a air high-efficiency product. refrigerants. They cool air by drawing warm outside air over a fan wetted media filter (pad). Water evaporating from the pad into water circulating pump the air decreases the air’s temper- Source: Adapted from the Energy Outlet, http://energyoutlet.com/res/cooling/evap_coolers 4

RMI’s Briefs: Home Energy Sizing: Correctly sizing an evapo- Maintenance: Dirt and mineral rative cooler for your home or for a sediment can build up in the water Did you know? room in your home is similar to siz- pad and filter of the evaporative Solar evaporative coolers ing a whole-house fan—you need cooler and should be cleaned or powered by photovoltaic (PV) cells are now available. to calculate the required ventilat- replaced once a month. If the cool- This is an ideal system

#3 Space Cooling ing power. To do this, use the same er is not used regularly, you can because PV cells operate formula used on the previous page usually get away with doing this most effectively during peak for whole-house fans. However, once a year. New high-quality sys- hours of the day—the instead of using 30 to 60 air tems, however, are equipped with hottest part of the day changes per hour use 20 to 40 air automatic flush systems that can when electricity is most expensive. changes per hour. The result will be piped to a nearby garden. be in cubic feet per minute (cfm), Three ways to increase the life of which you can then match to the pads include: work wonderfully (see Figure 3). appropriate system. Most evapora- This area of the country is also tive coolers range from 1,000 to • Using high quality water in the system; where central air-conditioning 8,000 cubic feet per minute (cfm) installations in new construction is while some are as powerful as • Installing a bleed-off system that stressing the existing electric sup- 25,000 cfm. dilutes mineral build-up; and/or ply infrastructure, so installing • Installing a sump dump or a evaporative coolers is a better Cost: Like other cooling systems, blow-down system that automat- solution. Evaporative coolers also the cost of an evaporative cooler ically dumps the water, getting use a fair amount of water, which depends mainly on the system’s rid of the dirt and particulate build-up. could increase your annual water ventilating power: the more power, bill by $15–20. Typical systems use the more expensive the system. Drawbacks: Evaporative coolers 3.5 to 10.5 gallons of water per Small, portable units typically are not very effective in humid cli- hour. However, the cooler’s higher range from $100 to $400 and have mates because water does not energy efficiency means water no installation cost. Fixed window easily evaporate into air that is consumption is reduced at the or wall-mounted units cost already high in humidity. As shown power plant. In addition, direct $800–2,000, including installation. below, most eastern U.S. states evaporative coolers increase the Larger, whole-house systems typi- and much of the Midwest are too humidity of the air inside the home, cally cost $2,000–4,000 including humid to use this type of cooling which can lead to discomfort. installation. Evaporative coolers system. However, in the western However, on very dry days, this can operate for twenty years United States, evaporative coolers can make a home more comfort- or more. able and can prevent wood furni- ture, doors, and fabrics from drying Figure 3: Map of evaporative cooling effectiveness in the United States out. Indirect evaporative cooling The dry climate of the western U.S. makes evaporative cooling there much more systems, on the other hand, can effective than in the Midwest, East, and South.7 deliver cool air without raising indoor humidity through the use of heat exchangers.

effective marginally effective ineffective

Source: Adapted from Home Energy Magazine Online, September/October 2001, http://hem.dis.anl.gov/eehem/01/010910.html 5

Heat Pumps mum SEER of 10. However, many is measured by its coefficient of RMI’s Briefs: Home Energy A heat pump can be used for both models are more efficient. We rec- performance (COP) for heating and heating and cooling. In the sum- ommend purchasing heat pumps energy efficiency ratio (EER) for mer, it acts as an air conditioner, with SEER of at least 13 and a cooling. Systems with Energy Star removing heat from air inside the HSPF around 9.0. Also look for heat labels will have a COP ranging from

house and carrying it outside. In pumps with Energy Star labels 3.3 to 3.6 and an EER of 14.2 to 16.2 #3 Space Cooling the winter, it operates in reverse, on them. This will ensure that you or higher. When purchasing a geo- removing heat from air outside the are purchasing a highly energy- thermal system, look for the Energy building and carrying it inside to efficient product. Star label to ensure you’re pur- warm the living space. There are chasing a highly efficient product. two main types of residential heat Geothermal heat pumps Geother- Many models have efficiencies pumps: air-source and geothermal, mal heat pumps use the ground, even higher than the Energy Star which are also known as ground- surface water, or underground system requires, with COPs greater source and geoexchange heat water as a heat source and heat than 5.0 and EERs greater than 17.0. pumps. For additional information sink. They use underground pipes, on heat pumps, refer to Home typically buried 3 to 6 feet below Sizing: As with all heating and Energy Brief No. 4: Space Heating. the surface, to take advantage of cooling systems, appropriately siz- the ground’s relatively constant ing heat pumps is extremely impor- year-round temperature (see Figure Air-source heat pumps Air-source tant. Undersizing or oversizing will heat pumps use outside ambient 4). The pipes are usually filled with result in inadequate performance, air to cool a home. They are similar a heat transfer fluid, which in sum- higher energy bills, and an uncom- to conventional central air condi- mer carries heat from inside the fortable home. The best way to tioning systems except they also house and releases it into the ensure correct sizing of both types have the ability to heat the home. ground thereby cooling your home. of heat pump systems is to hire a Some models can even provide air In winter, it extracts heat from the contractor that uses the Manual J circulation, air filtration, humidifi- ground to heat the home. sizing method developed by the cation, dehumidification, and water Air Conditioning Contractors of heating services. This may sound Geothermal heat pumps use 23–44 America (ACCA) or similar meth- like an amazing system. However, percent less energy than the more ods developed by the American before rushing out and buying one, commonly used air-source heat Society of Heating, Refrigerating, 8 note that air-source heat pumps pumps and, according to the and Air-Conditioning Engineers might not heat a home any better Environmental Protection Agency (ASHRAE). than an electric heating system in (EPA), they can save a typical extreme winter climates. A back- homeowner 30 to 70 percent in Maintenance: There are a number up system is often necessary to heating bills and 20 to 50 percent in of things you can do to improve the 8 help the air-source heat pump cooling costs. This could amount to efficiency and life of your heat achieve comfortable temperatures over $400 per year in energy sav- pump system: ings. The efficiency of this system in extreme winter climates (see • Have a technician service the Home Energy Brief No. 4: Space entire system annually; Heating for more information on Figure 4: Geothermal heat pump • Check the filters once a month the performance of different types and clean and replace as of heating systems). needed;

vertical loop • Clean the coils, fans, and ducts The efficiency of an air-source system at least once a year; heat pump is measured in terms of • For air-source units, keep the its heating season performance intake area clear of snow, ice, factor (HSPF) and seasonal energy and debris; and efficiency ratio (SEER). Currently, • For geothermal systems, have a national standards require air- technician check the inside of source heat pumps to achieve a Source: Adapted from Tool Base Services, Geothermal Heat Pumps, www.toolbase.org/ the heat exchanger and clear minimum HSPF of 6.8 and a mini- tertiaryT.asp?TrackID=&DocumentID=2093 away any mineral build-up. 6

RMI’s Briefs: Home Energy Cost: Air-source heat pumps typi- United States. Room air condition- • Sealing ducts can help save up cally cost $1,500–5,000, depending ers are generally smaller, individ- to $300 on annual cooling and on the size and installation require- ual units that have the ability to heating costs. Ordinary duct tape is not recommended—instead ments. Geothermal systems are cool only a single room. Room air use mastics (sealants), sheet typically about twice as expensive conditioners are typically mounted metal screws, or metal and plas-

#3 Space Cooling to install and typically cost on a wall or in a window, although tic bands; $7,500–15,000. These up-front costs there are portable units that can • Turn your air conditioner off or are high, but geothermal heat be moved all over the house. turn the thermostat up when pumps can pay for themselves you’re not home. Turning up the fairly quickly because they have Improving air conditioning thermostat by 10–15ºF during extremely low operating costs. efficiency the days when you’re out can In addition, many utilities offer The average air conditioned home save 5–15 percent on your rebates on such systems to help uses over 2,200 kilowatt-hours of energy bills; lower purchase and installation energy and costs the average • Set your thermostat at 78ºF or costs. Check with your local utili- homeowner around $200 per year, higher when the air conditioner ties to find out what rebates exist or more. Luckily, there are many is in use. DOE estimates that each degree below 78ºF increas- in your area. things you can do to maximize the efficiency of your air conditioner, es your energy consumption by improve its life, and save money eight percent; Conventional without sacrificing comfort: air conditioners Air conditioning is a complex cool- ing procedure that uses an evapo- Figure 5: Basic cooling cycle (top) and schematic (bottom) rator and condenser coil, a com- of a conventional air conditioner pressor, an expansion valve, and a compressor refrigerant (fluid or vapor). Air con- ditioners cool the air by pushing it high-pressure, low-pressure, high-temperature vapor low-temperature vapor across coils (cooled by the refrig- erant) that absorb the home’s heat; meanwhile a fan circulates the hot discharge warm moist air air cool air throughout the home (see AIR FLOW Figure 5 for a schematic of this condenser evaporator process). The evaporator is locat-

ed inside the home where it high-pressure, low-pressure, extracts heat from the air. The high-temperature liquid low-temperature liquid compressor then pressurizes the expansion valve evaporated fluid and sends it to

the condenser, which is located outside air outside. The fluid condenses and releases heat to the outdoors. OUTSIDE Then the fluid is expanded and condenser pumped back to the evaporator where the cycle repeats itself. cooled room air There are two main types of air fan motor conditioners: central air condition- filter blower ers and room air conditioners. Central air conditioners are ducted flow restriction INSIDE warm systems that can cool an entire room air compressor building. They are the most com- mon type of cooling system in the evaporator Source: Adapted from Canada Office of Energy Efficiency, http://oee.nrcan.gc.ca/publications/infosource/pub/home/Air_Conditioning_Your_Home_Section2.cfm 7

• Install a programmable therm- Buying a new air conditioner • Look for incentives offered by RMI’s Briefs: Home Energy stat to select appropriate times When buying a new air conditioner your energy utility—rebates to cool your home; and cash-back offers are often consider efficiency, sizing, and available for purchasing energy- • Change disposable filters or installation, because the right efficient air conditioners. clean permanent filters monthly; decisions can save you up to 30 • If you have a small or well-insu- percent on cooling costs. You #3 Space Cooling • Room air conditioners work best lated area to cool, or if you live when kept cool and out of direct should buy a new air conditioner if in a mild climate, a room air con- sunlight. Install them on the your existing model is more than ditioner is usually more economi- north-facing side of your home ten years old, as such models are cal than a central air conditioner. or in conjunction with shade trees and/or other passive cool- often only half as efficient as con- • Look for energy saving features ing measures on the west and temporary models. Sometimes you on the air conditioner, such as a south facing sides; can achieve energy savings by fan-only switch, a condenser simply replacing the outdoor con- on/off switch, variable-speed fan • Locate the compressor (the part controls, a programmable ther- that dumps waste heat outside) denser, but ask a technician to ensure it is properly matched to mostat, and high-efficiency com- in a cool shaded place. Clean pressors, motors, fans, and heat weeds and debris away and the indoor unit. When buying, con- transfer surfaces. A slide-out keep the coils on the back of the sider the following: filter also facilitates cleaning. unit dust free; • Have a licensed heating and Energy efficiency: Room air con- Sizing: With air conditioning sys- cooling professional conduct a ditioners are rated by their energy tems, equipment cost is propor- thorough inspection and clean- efficiency ratio (EER) and central tional to size, so be precise with ing of your central air condition- air conditioners are rated by their er once every year; and sizing. Studies have also shown seasonal energy efficiency ratio that about 50 percent of air condi- • Turn off or cycle your central air (SEER). The higher the number, the tioners are oversized. Choosing conditioner during peak hours of more efficient it is and the cheaper the correct air conditioner is very the day, when electricity is most it will be to operate. Pre-1992 mod- expensive. Contact your energy important because it is cheaper to utility for information on els often had SEER ratings around buy and install a smaller unit, and “demand response” or “direct 6 and EER ratings around 8. Today, you can save up to 20 percent on load control” options. however, national standards operating costs. Oversizing can require an EER of 9.7–9.8 for room also lead to indoor discomfort— air conditioners and a SEER of 10 too large a system will not remove for central air conditioners. Higher enough humidity, making the home ratings do exist, and it is recom- feel cold and damp. mended that you: Cost: Similar to evaporative cool- • Choose a central air conditioner ers, portable air conditioners with a SEER rating of 13 or high- er or a room air conditioner with range from $100–1,200 and have no an EER rating of 11 or higher. installation costs. Room air condi- tioners typically cost between $300 • Make sure your new air condi- and $1,500. If installation is need- tioner is Energy Star compliant. ed, add another $300–600. Central air conditioners typically cost between $3,000 and $7,000, includ- Did you know? ing installation. The American Council for an Energy-Efficiency Economy (ACEEE) lists the top rated air condition- ers available. For more information, visit www.aceee.org/ consumerguide/toprac.htm 8

RMI’s Briefs: Home Energy SUMMARY ADDITIONAL RESOURCES NOTES Using a conventional air condition- U.S. Department of Energy (DOE), 1. EIA (Energy Information Administration), “Residential Energy Consumption Survey: ing system is often the most Office of Energy Efficiency and Consumption and Expenditure Data Tables,” expensive and energy intensive Renewable Energy (EERE) — (Washington, DC: EIA, 2001), way to cool a home. If you are buy- Comprehensive and useful selection of www.eia.doe.gov/emeu/recs/recs2001/ fact sheets on all aspects of space detailcetbls.html#total. #3 Space Cooling ing a new air conditioner, first con- cooling, including a complete Home 2. DOE (Department of Energy), “Energy sider reducing heat gain in your Energy Booklet that can be down- Efficiency Pays,” (Washington, DC: EERE, home through passive cooling loaded for free (www.eere.energy.gov/ Undated), www.eere.energy.gov/buildings/info/ documents/pdfs/26290.pdf. measures and increasing ventila- consumerinfo/factsheets.html). 3. Rick Heede, Homemade Money: How to Save tion with low energy fans. Then California Energy Commission, Energy and Dollars in Your Home, (Snowmass, consider investing in more expen- Consumer Energy Center — California CO: Rocky Mountain Institute, 1995), pp. 101–102. sive cooling systems like evapora- is at the forefront of green energy ini- 4. DOE, “Cooling Your Home With Fans and tiatives. Their tools and resources are Ventilation,” (Washington, DC: EERE, Undated), tive coolers, heat pumps, and air www.eere.energy.gov/consumerinfo/fact- conditioners. If you already have practical and informative, and include sheets/ventilation.html. information on rebates and incentives an air conditioner, properly main- 5. Minnesota Department of Commerce, Home (www.consumerenergycenter.org). Cooling, (St. Paul, MN: MN DOC, Undated), p. 2, tain it so that it runs at peak effi- www.state.mn.us/cgi-bin/portal/mn/jsp/con- ciency. Always look for the Energy Minnesota Department of Commerce, tent.do?action=doc_contentlist&subchannel=- Star label when purchasing new Energy Information Center — 536881511&programid=536885406&sc3=null&sc2 Easy-to-read fact sheets and pam- =null&id=-536881350&agency=Commerce. cooling systems. The price tag phlets containing cost-effective 6. DOE, “Cooling Your Home With Fans and may be a little higher than on non- Home Cooling and Home Heating Ventilation,” (Washington, DC: EERE, Undated), Energy Star units, but you will ideas (www.commerce.state.mn.us). www.eere.energy.gov/consumerinfo/fact- pay off your investment every time sheets/ventilation.html. University of Central Florida, 7. Home Energy Magazine, “Refreshing you use the equipment. Florida Solar Energy Center — Evaporative Cooling,” Home Energy Magazine, Comprehensive resource on all (September/October 2001), aspects of home energy saving ideas, http://hem.dis.anl.gov/eehem/01/010910.html. from this well-recognized research 8. DOE, Geothermal Heat Pumps; Using the center (www.fsec.ucf.edu). Earth to Heat and Cool Buildings, (Washington, DC: EERE, September 1999), DOE/GO-10099-727. Geothermal, Geothermal Heat Pump Consortium — A comprehensive resource for anyone looking for more information on ground-source heat pumps (www.geothermal.org). American Council for an Energy- Efficient Economy (ACEEE) — A nonprofit organization that focuses on advancing energy efficiency. They list today’s most efficient home appliances on their website at www.aceee.org/consumerguide/mostenef.htm

Contact your local utility or energy office for information on rebates that may be available in your area on the purchase of new energy-efficient appliances. This publication is intended to help you improve the resource efficiency of your home. You should use your best judgment about your home, and seek expert advice when appropriate. Rocky Mountain Institute does not endorse any products mentioned and does not assume any responsibility for the accuracy or completeness of the information in this Brief. Written by Ramola Yardi, Andy Smith, and Katherine Wang. © Rocky Mountain Institute 2004.

Briefs Nos. 1–9 in the Home Energy series are funded by Stonyfield Farm, the Durst Organization Inc., the National Association of Realtors, and Deborah Reich.

Rocky Mountain Institute (RMI) is an independent, entrepreneurial, nonprofit applied research center that fosters the efficient and restorative use of natural, human and other capital to make the world secure, just, prosperous, and life-sustaining. We do this by inspiring business, civil society, and government to design integrative solutions that create true wealth.

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