Weatherizing Your Home for Energy Savings and Increased ComfortPublished on: August 29, 2013
When it comes to properly weatherizing a home and creating an efficiently operating HVAC system, the first step is having a home energy audit performed. A home energy audit helps the homeowner figure out both the big and small energy improvements that can be made in order to lower monthly heating and cooling bills, reduce a household’s carbon footprint, and make your home more comfortable.
Some energy improvements that can be made to your home will be fairly cheap, but others, such as installing a new furnace or A/C, are more pricey. These larger projects will save you energy and money, but an energy audit will help you understand whether a large project makes the most sense for your home and which high priority projects should be tackled first.
Who Needs an Energy Audit?
If your energy bills are higher than you think they should be, your house feels drafty or has hot and cold areas, and you can visually spot places where building materials don’t fit together correctly or utility lines and plumbing have gaps around the edges, then you likely will benefit from an energy audit. Older homes that haven’t had any sort of energy assessment often are the best candidates for a comprehensive energy audit. They were built at a time when energy efficiency wasn’t a priority, and may have shifted on their foundations over the years, creating gaps and cracks. Insulation can settle over time, too, or maybe not enough was installed in the first place. Meanwhile, newer houses also can have efficiency shortcomings, depending on the contractor. Because most homeowners are not especially knowledgeable about how and where to look for air leaks and inadequate insulation, and how to resolve these issues once found, a professional energy audit can be an essential diagnostic tool.
What’s Involved in the Energy Audit?
A professional energy audit will involve a thorough examination of all of your household’s energy aspects. This involves testing of combustion appliances and combustible gas lines, measuring the house and all of its external features, noting the type, age and expected efficiency of all HVAC equipment and larger energy-consuming appliances like refrigerators and washer and dryers, an examination of the attic, basement and crawl space, and undertaking various tests for airtightness and insulation.
Once all of the data is collected and analyzed, the energy auditor will then provide recommendations for improvement and system upgrades based on household factors such as comfort, health, payback, safety and condition in order to create an efficient plan of attack for weatherizing a home
What Sorts of Tests Are Performed in the House?
- The blower door test. This basic component of a complete home energy audit can guide you in improving your home’s total energy efficiency. To perform the test, the frame of the blower door device is set into a main doorway. This device is comprised of this frame, a covering that fits the frame’s perimeter, air pressure gauges, adjustable hinges, and a high-powered fan. Once in place, all of the building’s doors and windows will be snugly shut and the fan activated. By sucking air out of the house, the fan causes depressurization. Outside air will predictably find its way back into the house through various air leaks, and the gauges show how quickly this incoming air returns the house pressure to normal. The results of this test determine the amount of air leakage in a home. In tandem with the blower door test, your technician may use a thermographic scan to identify where air is leaking, as well as where insulation is lacking or missing altogether. (More on this later.) Using a simpler method, the energy auditor might patrol the inside perimeter of your house with a smoke stick in order to determine the exact location of air leaks. The smoke will waver at spots where air is coming into the house.
- Testing for carbon monoxide. Before air sealing a home, it is important for your health that a test for carbon monoxide and other potentially hazardous gasses in performed.
- Infrared camera or scan. Infrared cameras, also known as thermal imaging cameras or thermographic scanners, allow the user to view behind a wall and discover whether a sizable temperature difference between air inside and air outside exists. This helps determine whether there’s missing insulation, substantial air leakage spots, and the location of water leaks and built-up condensation. This last is important as excessively moist areas can contribute to the growth of mold, mildew and other fungi that cause poor indoor air quality and deteriorating effects to building materials.
1. Weatherizing a Home
Once the energy audit has been completed, it’s time to begin weatherizing your home. For a basic plan of action, concentrate on targeting four major areas: the prevention of heat gain and loss, proper insulation and ventilation, sealing exterior air leaks, sealing ductwork.
Window and rooftop heat gain and loss. In the summer, heat gain through your windows and attic roof can cause your air conditioning system to work overtime, costing you more money in energy bills and maintenance needs. Solar heat that infiltrates through windows can account for as much as half of a home’s overall summer heat gain. In the winter, the same strain put on air conditioning units is put on the home’s heating system when heated air is lost through windows, air leaks on your home’s perimeter, and ceilings. To reduce heat transfer:
• Add exterior and interior blinds
• Add window draperies
• Install reflective window film
• Add awnings
• Coat your roof with a reflective material or install light-colored roofing materials
• Where possible, replace single-pane windows with storm windows or otherwise more efficient double-pane and low-emissivity windows
2. Proper insulation and ventilation. Proper insulation will help reduce unwanted heat transfer, and proper ventilation will ensure that built-up heat can be transferred easily to the outdoors and not to your indoor environment.
• Use a balance of intake and exhaust vents for attic ventilation
• Use a minimum of R-30 insulation for the space between your top floor’s ceiling and the attic
3. Sealing air leaks. Air sealing is a significant aspect of weatherizing a home and should have its own action plan. Homes that have not properly air sealed their exterior shell are susceptible to contaminated and poor indoor air quality, high energy bills, and sacrificed comfort. When locating and sealing air leaks, try starting with big leaks and moving to small. Search first for the biggest holes, such as areas around attic knee-walls, bathtub drain holes, and mechanical chases. The ceiling between your attic and top living floor along with your ground floor will be where most of your medium and larger air leaks are located. Once the biggest holes have been repaired, search for air leakage around the furnace flue and any places where a square has been cut away to make for cylindrical piping and lines.
For medium to large size holes, first add spray foam and then use an approved caulking compound to seal in any gaps. For the smallest of holes and gaps through which plumbing, ducting and electrical wiring penetrate the walls, use a caulking compound when weatherizing a home. Additionally, check for any dirty or sooty spots in the ceiling paint and carpet as this may indicate possible air leaks within wall and ceiling joints that needed to be caulked. For the final step in air sealing, caulk and weatherstrip around any outside-leading doors and windows thought to possibly leak air.
4. Sealing ductwork. As many as 90 percent of all occupied buildings in the United States have ductwork that cannot operate at top efficiency because of air leaking through holes, gaps and poorly connected ductwork. This causes conditioned and heated air to leak through exterior walls and into attic spaces, garages and crawlspaces, and be wasted. Exposed ductwork can be repaired by the well-equipped homeowner with a duct sealing adhesive such as butyl tape, foil tape, mastic or other heat-resistant tape. However, sometimes gaps and poorly connected ductwork are located in between walls and ceilings, hard-to-reach places for the novice handyman. In such scenarios, consider contacting a qualified professional for proper repair.
The goal of properly weatherizing a home is to take measures that will ultimately cut energy costs. By adhering to the above advice and any additional information gained in a personal home energy audit, your household can significantly cut its total energy consumption, ultimately reducing heating and electrical demand while also improving the lifespan of your HVAC equipment. In addition to these heating and cooling solutions for weatherizing a home, habit changes such as using ceiling fans in conjunction with the household air conditioner and changing the air conditioner filter once a month during the cooling season can help cut household energy costs.
For more information about weatherizing a home, or to learn about other high-efficiency HVAC products and services for your Southeastern U.S. home, contact the professionals at AirConditioningSouthEast.com. We can help you find a highly trained and qualified contractor in your area.