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Home energy audit

A home energy audit is often the first step in making your home more energy efficient. You’ll find out how much energy it takes to power your home and how efficiently that energy is used. Then you can decide what steps you want to take to save on energy. By correcting problem areas or improving energy efficiency, you could save significant money over time. Plus, you’ll be doing your part to reduce dependence on fossil fuels.

Let’s get started

There are two ways to start:

The U.S. Department of Energy’s Energy Saver website has some great information you can use for your own home energy audit. Here are some of the basics:

Do a visual inspection.

On the outside of your house, look at all areas where two different building materials meet, including:

  • All exterior corners
  • Outdoor water faucets
  • Where siding and chimneys meet
  • Areas where the foundation and the bottom of exterior brick or siding meet

Inside, inspect around these areas for any cracks and gaps that could cause air leaks:

  • Electrical outlets
  • Switch plates
  • Door and window frames
  • Electrical and gas service entrances
  • Baseboards
  • Weather stripping around doors
  • Fireplace dampers
  • Attic hatches
  • Wall- or window-mounted air conditioners
  • Cable TV and phone lines
  • Where dryer vents pass through walls
  • Vents and fans

Seal air leaks.

The potential energy savings from reducing air leaks in your home could range from 5% to 30% per year. Plus, with many of those pesky leaks gone, your home will be much more comfortable.

A visual inspection will show you the air leakage problem spots. When you find them, seal them with the appropriate materials. This is a great start, but you will also benefit from finding the less obvious gaps to properly air seal your home.

Check to see if the caulking and weather stripping are applied properly, leaving no gaps or cracks, and are in good condition. Check the exterior caulking around doors and windows, and see whether exterior storm doors and primary doors seal tightly.

Inspect windows and doors. If you can rattle the windows or see daylight around a door or window frame, you have leaks. Check the storm windows to see if they fit and are not broken. Consider replacing your old windows and doors with newer, high-performance ones. If new factory-made doors or windows are too costly, you can install low-cost plastic sheets over the windows.

Remember, ventilation is critical.

When sealing your home, be aware of the danger of indoor air pollution and combustion appliance "backdrafts,” which may occur when various combustion appliances and exhaust fans in the home compete for air. An exhaust fan may pull the combustion gasses back into the living space, creating a potentially dangerous and unhealthy situation in the home.

If you heat your home with natural gas, fuel oil, propane, or wood, be sure each of your appliances has an adequate air supply. Generally, one square inch of vent opening is required for each 1,000 Btu of appliance input heat. Burn marks or soot around the appliance burner, vent collar, or visible smoke anywhere in a room while the appliance is operating, indicate poor draft. When in doubt, contact your local utility company, energy professional, or ventilation contractor.

Check insulation.

If you don't have the recommended insulation levels in your home, you could be losing a lot of heat and wasting energy. With today's energy prices (and future prices that will probably increase), the level of insulation in your home might not be enough, especially if you have an older home.

When your attic hatch is located above an air-conditioned space, make sure it’s as heavily insulated as the attic, is weather stripped, and closes tightly. In your attic, check to make sure the openings around pipes, ductwork, and chimneys are sealed. When you find a gap, seal it with an expanding foam caulk or some other permanent sealant. When sealing gaps around chimneys or other heat producing devices, be sure to use a non-combustible sealant.

While you are inspecting the attic, check to see if there is a vapor barrier under the attic insulation. The vapor barrier might be tarpaper, Kraft paper attached to fiberglass batts, or a plastic sheet. If you don't have a vapor barrier, you might consider painting the interior ceilings with vapor barrier paint. This reduces the amount of water vapor that can pass through the ceiling. Large amounts of moisture can reduce the effectiveness of insulation and promote structural damage.

Make sure that the attic vents are not blocked by insulation. You should also seal any electrical boxes in the ceiling with flexible caulk (from the living room side or attic side) and cover the entire attic floor with at least the current recommended amount of insulation.

Inspect heating and cooling equipment.

Remember to inspect your heating and cooling equipment every year, or as recommended by the manufacturer. If you have a forced-air furnace, be sure to check and replace filters when needed. It’s a good idea to change your filters every month or two, especially during periods of high usage. Have a professional check and clean your equipment once a year.

If the unit is more than 15 years old, consider a new, energy-efficient model. A new unit may greatly reduce your energy consumption, especially if your existing equipment is in poor condition. Check your ductwork for dirt streaks, especially near seams. These indicate air leaks, and they should be sealed with a duct mastic. Insulate any ducts or pipes that travel through unheated spaces. An insulation R-value of 6 is the recommended minimum.

Look at lighting.

Energy for lighting accounts for about 10% of your electric bill. Check the light bulbs around your house and replace inefficient ones with a more efficient choice, such as energy-saving incandescent, compact fluorescent lamps (CFLs), or light-emitting diodes (LEDs). When shopping for light bulbs, consider the brightness you want and look for lumens and the Lighting Facts label. Your electric utility may offer rebates or other incentives for purchasing energy-efficient bulbs. Also look for ways to use controls such as sensors, dimmers, or timers to reduce your lighting use.

Don’t forget appliances and electronics.

The major and small appliances and electronics – like computers, tablets, game systems, even smartphones – in your home all use energy. Take a look at your appliances and electronics and estimate their energy use. Then consider ways to cut back like:

  • Unplugging an item when it is not in use to prevent “phantom load,” which is the power used by devices when they are switched off.
  • Changing the settings or using the item less often.
  • Purchasing a new, more efficient product. Learn more about shopping for efficient appliances and electronics here.

Develop your own whole-house plan.

Once you know where your home is losing energy, you can develop a plan to make improvements. Here are some key considerations in developing a plan for your whole house:

  • Identify how much money you spend on energy over the year.
  • Review your do-it-yourself audit to pinpoint your largest energy losses.
  • Think about whether the energy-saving measures provide additional benefits that are important to you — for example, increased comfort from installing double-paned, efficient windows.
  • Determine which repairs you have the time and skills to handle on your own and for which it’s best to use a contractor.
  • Develop a schedule for making repairs – start with easier improvements like caulking and weather stripping.
  • Set a budget.
  • Do the math to understand how long it will take for your investment in energy efficiency to pay for itself with energy cost savings.
Walk through your home, and you can pinpoint some of the easier areas to address. As you do it, keep a checklist of areas you have inspected and problems you found. It will help you prioritize your energy efficiency upgrades.

For a more thorough home energy audit, call a professional technician. Professional energy assessments generally go into great detail to assess your home's energy use. The energy auditor will do a room-by-room examination of your home and review your past utility bills. Many professional energy assessments will include a blower door test to determine whether your home is airtight. Most will also include thermographic (infrared) scanning to detect thermal defects and air leakage in your home.

How to find and select an energy auditor.

There are several ways you can locate professional energy assessment or auditing services:

  • Your state or local government energy or weatherization office may help you identify a local company or organization that performs audits.
  • Your electric or gas utility may conduct residential energy assessments or recommend local auditors.
  • Your telephone directory under headings beginning with the word "Energy" may list companies that perform residential energy assessments.
  • The Residential Energy Services Network provides a directory of certified energy raters and auditors near you.

Before contracting with an energy auditing company, you should take the following steps:

  • Get several references, and contact them all. Ask if they were satisfied with the work.
  • Call the Better Business Bureau and ask about any complaints against the company.
  • Make sure the energy auditor uses a calibrated blower door.
  • Make sure they do thermographic inspections or contract another company to conduct one.

How to prepare for your audit.

Before the energy auditor visits your house, make a list of any problems you know about, such as condensation and uncomfortable or drafty rooms. Have copies or a summary of the home's annual energy bills. (Your utility can get these for you.) The auditor will use this information to establish what to look for during the audit.

The auditor will first examine the outside of your home to determine its size and features (e.g. wall area, number and size of windows). Then the auditor will ask about you and your family:

  • Is anyone home during working hours?
  • What is your average thermostat setting for summer and winter?
  • How many people live here?
  • Is every room in use?

Your answers may help uncover some simple ways to reduce your household's energy consumption. Walk through your home with the auditors as they work and ask questions.

A professional home energy audit is the most thorough way to determine where your home is losing energy. Watch this video for a quick overview of a professional home energy audit.

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