An energy audit is something every homeowner should do. It helps to identify changes that you can make which will save money and reduce your carbon footprint. You can either do it yourself or hire a professional auditor. Another option is to check with your utility company or local government to see if they offer auditing assistance. You can also check with the U.S. Department of Energy’s Energy Efficiency and Renewable Energy Information Center. On this site there is a link to state and federal audit assistance programs. There are also a variety of tax credits available for improving your home’s energy efficiency or adding renewable energy.
MSN Green offers the following tips for a do-it-yourself home energy audit:
The best place to start your audit is to locate areas where air leaks may occur by running your hand around doors, windows, baseboards and electrical outlets. If it’s not a windy day and you can’t locate any leaks, try pressurizing your home: close all windows, doors and flues and then turn on all your exhaust fans (typically in your bathrooms and kitchen). Another trick is to hold a smoking incense stick near windows and doors to help indicate areas of leakage.
Any gaps or areas of air leakage should be sealed with simple caulking or weather stripping available at hardware stores. Reducing drafts in a home can result in energy savings of 5 to 30 percent per year.
Just as important as controlling air leaks is ensuring your home is well insulated. Recommended insulation levels, or ‘R’ values, have been steadily increasing as concerns over fuel prices and environmental issues mount. Insulation is a relatively inexpensive product that can have a huge impact on your energy bills. Improve insulation in the easy-to-access areas first such as the attic floor between your basement and living space.
Many people are now insulating existing exterior walls by blowing in insulation. While this method can be effective it can also leave gaps — do it only after sufficient insulation has been installed in the easy-to-reach parts of the house.
If your windows are single glazed (i.e., one pane of glass), consider retrofitting double-glazed windows. A double-glazed window can cut heat loss in half. The retrofit double-glazing market is fairly competitive and costs have come down in recent years. Be sure to investigate the quality of the company you choose and remember, not all windows have to be done at once.
An alternative to double-glazing is to install floor-length insulated curtains with pelmets. A pelmet is a frame placed above a window that reduces convection currents across the window. Installing insulated curtains and pelmets can have almost the same impact as double-glazing, but they only work when they’re closed.
Hot Water Heating
Heating hot water can account for up to 25 percent of a home’s energy needs. The most significant savings usually come by switching to a more efficient system. But there are a number of other less expensive measures you can take to reduce water heating energy. Inspect the pipes around your tank and ensure they’re insulated and that the insulation is in good condition. If the tank is warm to the touch, purchase an insulating blanket to wrap around the tank or, better yet, replace the tank altogether. Set your water heater to 120ºF — any higher is unnecessary and leads to even greater heat losses. Additionally, installing low-flow shower heads can significantly reduce a home’s hot water usage. If you’re considering replacing your hot water system, check out solar, heat pump or instantaneous hot water heating options. Selecting the best system will depend on your climate, how and when you use water, and the number of people in your home.
Heating Ventilation and Air Conditioning (HVAC)
An HVAC system typically represents a home’s single largest source of energy use, representing over 50 percent of the total energy use in U.S. houses. Improving the thermal performance of your home (see above) is the single biggest opportunity to reduce HVAC energy use. Other measures you can take to reduce HVAC energy use include installling a programmable thermostat and fixing leaky ducts. If you have an old forced-air delivery system, it may be worthwhile to have your ducts examined by a professional. Options for new HVAC systems include heat pumps, geothermal (or ground source) heat pumps, condensing boilers and pellet fires, which burn compressed wood waste.
If you have a home that is constructed on a concrete slab you might consider replacing carpeting with tiles in rooms that receive direct sunlight. Doing so will help control overheating in the summer and provide free passive heating in the winter.
Take a close look at the types of lights in your home. Consider replacing existing incandescent bulbs with compact fluorescents lights (CFLs). Compact fluorescents use approximately one-fifth the energy of a typical incandescent bulb and can last up to 10 times longer. They’re now available in a variety of shapes and sizes and can replace bulbs in almost any fixture. Compact fluorescents should be recycled or disposed of properly due to the small amount of mercury they contain.
Other alternatives to the incandescent bulb are light emitting diodes (LEDs) and halogen replacement bulbs. While LED technology has improved immensely over recent years for the most part LEDs will not yet produce the light levels of the bulbs they are designed to replace. However they are ideal for some applications and they can be used with a dimmable fixture unlike most CFLs. The downside to LED lights is their high initial cost. But when you factor in their longevity — up to 50,000 hours – they’ll more than pay for themselves over their lifetime.
In most homes the refrigerator is the single biggest plug load. To assess your fridge examine the door seals. If you can feel cold air leaking out it’s a good idea to replace them. Old refrigerators can be extremely inefficient. If your fridge is more than five to ten years old consider replacing it. A modern Energy Star refrigerator can use 40 percent less energy than a conventional model sold just seven years ago. And if you purchase a new fridge, resist the temptation to make your old fridge your new beer cooler.
Many modern appliances have a standby load. A standby load is the power drawn by microwaves, stereos, TVs, dishwashers and other appliances while they’re waiting to be used. While the power of any one of these appliances in standby mode is not significant, over a period of a year the cumulative energy from multiple appliances can add up. Consider unplugging appliances that are used infrequently to reduce standby power. Or plug appliances into a power board and turn off the power board when the appliance is not in use.
If you’re curious about how much energy your appliances are drawing, pick up a centameter. It’s a small device that provides a digital display of the power your house is drawing. Place one in a visible location and it’ll function as a great reminder to everyone in your home just how much energy you’re using.
Your first goal in a home energy audit is to pluck the low-hanging fruit. First tackle the measures that can be done easily and cheaply like draft-proofing and replacing the seals on your fridge. Next on your list should be those measures that will give you the greatest return on your investment, like improving insulation and replacing leaky ducting. Your last step should be those big-ticket items, like installing a new HVAC system or retrofitting double-glazed windows.