Heating and cooling your home uses more energy and costs more money than any other system in your home—typically making up about 54% of your utility bill.
No matter what kind of heating and cooling system you have in your house, you can save money and increase your comfort by properly maintaining and upgrading your equipment. But remember, an energy-efficient furnace alone will not have as great an impact on your energy bills as using the whole-house approach. By combining proper equipment maintenance and upgrades with recommended insulation, air sealing, and thermostat settings, you can cut your energy use for heating and cooling—and reduce environmental emissions—from 20%-50%.
Heating and Cooling Tips
Household Heating Systems: Although several different types of fuels are available to heat our homes, more than half of us use natural gas. Source: Buildings Energy Data Book 2010, 2.1.1 Residential Primary Energy Consumption, by Year and Fuel Type (Quadrillion Btu and Percent of Total) Set your programmable thermostat as low as is comfortable in the winter and as high as is comfortable in the summer, as well as when you’re sleeping or away from home.
Clean or replace filters on furnaces and air conditioners once a month or as recommended.
Clean warm-air registers, baseboard heaters, and radiators as needed; make sure they’re not blocked by furniture, carpeting, or drapes.
Eliminate trapped air from hot-water radiators once or twice a season; if unsure about how to perform this task, contact a professional.
Place heat-resistant radiator reflectors between exterior walls and the radiators.
Turn off kitchen, bath, and other exhaust fans within 20 minutes after you are done cooking or bathing; when replacing exhaust fans, consider installing high-efficiency, low-noise models.
During winter, keep the draperies and shades on your south-facing windows open during the day to allow the sunlight to enter your home and closed at night to reduce the chill you may feel from cold windows.
During summer, keep the window coverings closed during the day to block the sun’s heat.
Long-Term Savings Tips
Select energy-efficient products when you buy new heating and cooling equipment. Your contractor should be able to give you energy fact sheets for different types, models, and designs to help you compare energy usage.
For furnaces, look for high Annual Fuel Utilization Efficiency (AFUE) ratings. The national minimum is 78% AFUE, but there are ENERGY STAR® models on the market that exceed 90% AFUE. For air conditioners, look for a high Seasonal Energy Efficiency Ratio (SEER). The current minimum is 13 SEER for central air conditioners. ENERGY STAR models are 14.5 SEER or more.
Air Ducts
Your air ducts are one of the most important systems in your home, and if the ducts are poorly sealed or insulated they are likely contributing to higher energy bills.
Your home’s duct system is a branching network of tubes in the walls, floors, and ceilings; it carries the air from your home’s furnace and central air conditioner to each room. Ducts are made of sheet metal, fiberglass, or other materials.
Ducts that leak heated air into unheated spaces can add hundreds of dollars a year to your heating and cooling bills. Insulating ducts that are in unconditioned spaces is usually very cost-effective. If you are installing a new duct system, make sure it comes with insulation.
Sealing your ducts to prevent leaks is even more important if the ducts are located in an unconditioned area such as an attic or vented crawl space. If the supply ducts are leaking, heated or cooled air can be forced out of unsealed joints and lost. In addition, unconditioned air can be drawn into return ducts through unsealed joints.
Although minor duct repairs are easy to make, qualified professionals should seal and insulate ducts in unconditioned spaces to ensure the use of appropriate sealing materials.
Minor Duct Repair Tips
Check your ducts for air leaks. First, look for sections that should be joined but have separated and then look for obvious holes.
If you use tape to seal your ducts, avoid cloth-backed, rubber adhesive duct tape—it tends to fail quickly. Instead, use mastic, butyl tape, foil tape, or other heat-approved tapes. Look for tape with the Underwriters Laboratories (UL) logo.
Remember that insulating ducts in the basement will make the basement colder. If both the ducts and the basement walls are not insulated, consider insulating both. Water pipes and drains in unconditioned spaces could freeze and burst if the heat ducts are fully insulated because there would be no heat source to prevent the space from freezing in cold weather. However, using an electric heating tape wrap on the pipes can prevent this. Check with a professional contractor.
Hire a professional to install both supply and return registers in the basement rooms after converting your basement to a living area.
Be sure a well-sealed vapor barrier exists on the outside of the insulation on cooling ducts to prevent moisture condensation.
If you have a fuel-burning furnace, stove, or other appliance or an attached garage, install a carbon monoxide (CO) monitor to alert you to harmful CO levels.
Be sure to get professional help when doing ductwork. A qualified professional should always perform changes and repairs to a duct system.
Heat Pumps
Heat pumps are the most efficient form of electric heating in moderate climates, providing up to three times more heat than the energy they use. A heat pump can reduce your electricity use for heating by 30%-40% compared to electric resistance heating such as furnaces and baseboard heaters.
A heat pump does double duty as a central air conditioner by collecting the heat inside your house and pumping it outside.
There are three types of heat pumps: air-to-air, water source, and geothermal. They collect heat from the air, water, or ground outside your home and concentrate it for use inside.
Geothermal (or ground-source) heat pumps have some major advantages. They can reduce energy use by 30%-60%, control humidity, are sturdy and reliable, and fit in a wide variety of homes.
Heat Pump Tips
Do not set back the heat pump’s thermostat manually if it causes the electric-resistance heating to come on. This type of heating, which is often used as a backup to the heat pump, is more expensive.
Install or have a professional install a programmable thermostat with multistage functions suitable for a heat pump.
Clean or change filters once a month or as needed, and maintain the system according to manufacturer’s instructions.
Long-Term Savings Tip
If you heat your home with electricity and live in a moderate climate, consider an energy-efficient heat pump system to reduce your energy consumption.
Passive Solar Heating and Cooling
Using passive solar design to heat and cool your home can be both environmentally friendly and cost-effective. In many cases, your heating costs can be reduced to less than half the cost of heating a typical home.
Passive solar design can also help lower your cooling costs. Passive solar cooling techniques include carefully designed overhangs and using reflective coatings on windows, exterior walls, and roofs. Newer techniques include placing large, insulated windows on south-facing walls and putting thermal mass, such as a concrete slab floor or a heat-absorbing wall, close to the windows.
A passive solar house requires careful design and siting, which vary by local climate conditions. If you are considering passive solar design for a new home or a major remodel, consult an architect familiar with passive solar techniques.
Passive Solar Tips
Keep all south-facing glass clean.
Make sure that objects do not block sunlight on concrete slab floors or heat-absorbing walls.
Natural Gas and Oil Heating
If you plan to buy a new heating system, ask your local utility or state energy office about the latest technologies on the market. For example, many newer models have designs for burners and heat exchangers that are more efficient during operation and cut heat loss when the equipment is off.
Consider a sealed-combustion furnace—they are safer and more efficient.
Long-Term Savings Tip
Install a new energy-efficient furnace to save money over the long term. Look for the ENERGY STAR and EnergyGuide labels to compare efficiency and ensure quality.
Programmable Thermostats
You can save as much as 10% a year on heating and cooling by simply turning your thermostat back 7° -10° F for 8 hours a day from where you would normally set. (If you have a heat pump, don’t do this without a programmable thermostat). You can do this automatically by using a programmable thermostat and scheduling the times you turn on the heating or air conditioning. As a result, the equipment doesn’t operate as much when you are asleep or not at home.
Programmable thermostats can store multiple daily settings (six or more temperature settings a day) that you can manually override without affecting the rest of the daily or weekly program.
Programmable Thermostat Tips
Hot winter tip — Use a programmable thermostat to automatically turn down the heat at night or when you’re away from home.
Cool summer tip — In the summer, save money by automatically turning up the air conditioner at night or when you’re away from home.
Air Conditioners
Buying a bigger room air conditioner won’t necessarily make you feel more comfortable during the hot summer months. In fact, a room air conditioner that’s too big for the area it is supposed to cool will perform less efficiently and less effectively than a smaller, properly sized unit. Central air conditioning systems need to be sized by professionals.
If you have a central air system in your home, set the fan to shut off at the same time as the compressor, which is usually done by setting the “auto” mode on the fan setting. In other words, don’t use the system’s central fan to provide air circulation—use circulating fans in individual rooms.
Instead of air-conditioning, consider installing a whole-house fan. Whole-house fans work in many climates and help cool your home by pulling cool air through the house and exhausting warm air through the attic. Use the fan most effectively to cool down your house during cooler times of the day: your home will stay cooler through the hotter times of the day without using the fan.
Cooling Tips
Set your thermostat at as high a temperature as comfortably possible in the summer, and ensure humidity control if needed. The smaller the difference between the indoor and outdoor temperatures, the lower your overall cooling bill will be.
Avoid setting your thermostat at a colder setting than normal when you turn on your air conditioner. It will not cool your home any faster and could result in excessive cooling and, therefore, unnecessary expense.
Consider using an interior fan along with your window air conditioner to spread the cooled air through your home without greatly increasing your power use.
Avoid placing appliances that give off heat such as lamps or TVs near a thermostat.
Long-Term Savings Tips
If your air conditioner is old, consider buying an energy-efficient model. Look for the ENERGY STAR and EnergyGuide labels—qualified room air conditioners are 10% more efficient, and qualified central units are about 14% more efficient than standard models.
If you’ve ever stood on a roof on a hot summer day, you know how hot it can get. The heat from your roof makes your air conditioner work even harder to keep your home cool.
If you are building a new home, decide during planning whether you want a cool roof, and if you want to convert an existing roof, you can:
Retrofit the roof with specialized heat-reflective material
Re-cover the roof with a new waterproofing surface (such as tile coating)
Replace the roof with a cool one
A cool roof uses material that is designed to reflect more sunlight and absorb less heat than a standard roof. Cool roofs can be made of a highly reflective type of paint, a sheet covering, or highly reflective tiles or shingles.
By installing a cool roof, you can lower the temperature of your roof by up to 50°F and save energy and money by using less air conditioning. Cool roofs make spaces like garages or covered patios more comfortable.
As cool roofs become more popular, communities will benefit from fewer power plant emissions and less demand for new power plants. Cool roofs can lower outside air temperatures, reducing heat islands in urban areas.
You may also consider installing a green roof. Green roofs are ideal for urban buildings with flat or shallow pit roofs and can include anything from basic plant cover to a garden. The primary reasons for using this type of roof include managing stormwater and enjoying a rooftop open space. Green roofs also provide insulation, lower the need for heating and cooling, and can reduce the urban heat island effect. This roof type can be much more expensive to implement than other efficient roof options, so you should carefully assess your property and consult a professional before deciding to install a green roof.
Landscaping is a natural and beautiful way to keep your home cool in summer and reduce your energy bills. A well-placed tree, shrub, or vine can deliver effective shade, act as a windbreak, and reduce your energy bills. Buildings and trees are natural partners — deciduous trees planted on the south and west sides will help keep your house cool in the summer and allow the sun to shine through the windows in the winter. Carefully positioned trees can save up to 25% of the energy a typical household uses.¹ Research shows that summer daytime air temperatures can be 3°-6° cooler in tree-shaded neighborhoods than in treeless areas. ²
A lattice or trellis with climbing vines or a planter box with trailing vines shades the home while admitting cooling breezes to the shaded area.
1. Lawrence Berkeley National Laboratory, The Potential for Reducing Urban Air Temperatures and Energy Consumption Through Vegetative Cooling 2. Lawrence Berkeley National Laboratory, The Potential for Reducing Urban Air Temperatures and Energy Consumption Through Vegetative Cooling
