Are you an energy efficiency expert? Already ditched incandescent bulbs for CFLs? Got more ENERGY STAR ® products than aisle 7 at your local home improvement store? Look down on single-pane windows as oh so... thin? Then consider these advanced energy-saving actions.
Your home’s air leakage represents 5 to 40 percent of your space heating and cooling costs. Minimizing air leakage is one of the best ways to reduce your home energy costs, improve indoor air quality and improve the comfort of your home. Air sealing, or the process of sealing the cracks where air can leak out, includes simple actions such as installing a door sweep on an exterior door and caulking interior trim. Advanced practices can include sealing gaps in an attic flat or in a basement crawl space.
Home Performance and Weatherization contractors use diagnostic tools to measure building air leakage. ‘Blower-door’ tests and infrared cameras help measure and identify places where air is leaking, quantify leakage and verify the successful implementation of air sealing measures.
DIY - Basic, Low-Cost, High-Return Improvements:
Take the time to caulk the seams around interior trim, such as along baseboards and around windows. Inspect the weather stripping (the foam or rubber gasket that compresses when the door is closed) around exterior doors and attic or knee-wall hatch doors. If it is ripped or gaping, replace it. Install window-film over old leaky windows for simple yet effective air sealing.
Keep an eye out for cobwebs in basement spaces. Spiders like to build webs where there is air movement. Use 1-part expandable foam to seal any gaps larger than ¼ inch. Most basements are semi-conditioned and affect the air quality and temperature in the main house, so air sealing the basement perimeter will benefit whole-house energy efficiency and will make the main floors more comfortable.
Air leakage in between a properly vented attic and a conditioned space below can reduce insulation effectiveness by over 75 percent, so if you are improving the insulation in your attic, it is imperative to include air sealing. For optimal air barrier performance, the attic flat should be sealed by a skilled technician.
Additional air leakage pathways that should be sealed include chase-ways and major openings around chimneys, plumbing, ducts and drop-ceilings (bypasses). Interior wall top-plates, wiring and plumbing penetrations, seams around fixtures such as can-lights and fans, and access doors are all places for air to escape. These pathways are small in size but abundant, so they can quickly lead to a sizable air leakage directly to the outside!
Air Sealing for Better Building Durability:
In addition to comfort and energy savings, professional air sealing of the attic flat is an important component of addressing building durability issues. Visible signs of air sealing failures include extreme ice damming (the icicles that form around the perimeter of your roof in the winter) and premature rot on the underside of the roof sheathing. Air sealing will reduce the amount of warm, moist air that escapes into the attic, where it can condense upon cold surfaces and cause these problems.
Note: Chimney chase-ways and some fixtures require special code-compliant fire-rated air sealing techniques that must be performed by a professional.
Light Emitting Diodes (LEDs)
LEDs are the new frontier in efficient lighting. They can provide very targeted brightness and shades of light in nearly any shape and size, can last as long as two decades, and use much less energy than traditional incandescent bulbs. LEDs are excellent for recessed fixtures and other applications where a CFL can be impractical. They last longer than CFLs, and include no harmful mercury as CFLs do. The downside of LEDs is their cost: a single bulb can cost $25 to $40. However, for light fixtures that you use often, LEDs can still pay for themselves relatively quickly. And with LEDs, you’ll be much more state-of-the-art than your peers who are still using CFLs. When you choose LEDs, look for ENERGY STAR qualified ones.
Low-E window film
This plastic film with low-emissivity (low-E) coating can reduce heat loss through old windows by 30 to 50 percent. (The coating is blocking heat and ultraviolet rays while continuing to let in visible light.) It’s a simple solution that’s much cheaper than replacing all the windows in an old house. For the summer, apply the film to the outside window pane to reflect heating solar rays; you’ll then do an easy pane-switch for the winter to trap in heat.
Solar shades are like a more energy efficient version of blinds, but they fit on the outside of your windows. They reflect light away from your windows, reducing heat absorption by up to 90 percent and keeping your home cool during the summer. They are excellent for South-facing rooms that you do not use often.
Older single-pane windows are terrible insulators. New double- and triple-pane windows have insulating gasses in the interior, low-E coating, and low solar gain that helps dramatically reduce summer cooling (and winter heating) costs.