Insulate to cut home energy costs
March 19, 2012
If you could save from 30 to 50 percent on your annual heating and cooling bills, would you make the investment? Ultimately it doesn't pay to spend a lot of money on replacement doors and windows if you don't seal your home properly. Your home is wrapped by a thermal envelope, the net protection you get from insulation and controlling heat gain or loss through leaks. If you want to start with a small investment and work toward creating a green home, start with insulation. Spray foam installation costs from $1.50 to $3.00 per square foot.
Insulation is rated by its R-value, the density and thickness of the product and how well it governs the movement of outdoor and internal air. The higher the R-value, the stronger the insulating properties. If you have an uncovered, unfinished attic space, start by insulating there. Attic floors typically take as much as two inches of insulation, or an R-38 rating.
Insulation goes green
Sustainable insulation products are found on the market today, if using non-synthetic products fits your lifestyle. Hemp, straw, cotton and wood are known to offer the same amount of insulation as synthetics, and they're free of volatile chemicals. Some recycled insulation products come from old newspapers or blue jeans.
Another step toward building up your thermal envelope, though more expensive, is to choose replacement doors with insulating foam cores and replacement windows with low-E coatings to further block unwanted heat gain or loss.
Be sure to include a budget for weatherstripping, even if you choose high quality doors and windows. Install or replace your door sweeps. Open-cell foams and felt products are popular for their ease of spray or tape application. However, vinyl insulation holds up longer and withstands harsh weather.
The usual suspects for air leaks include the perimeter of electrical boxes and wall plates, wall openings for pipes or conduit, your foundation, baseboards, heat and air vents, the attic hatch and the frames of doors and windows. Your garage may also be an unwanted portal for cold winter air. You can buy foam panel insulation kits for garage doors. They come with an expanded polystyrene core and are faced with high-impact styrene laminates.
Insulation by location
The Department of Energy recommends tension-seal insulation inside the tracks of windows and the top of your doors. Felt roil insulation is effective when fitted into a door jamb.
Closed-cell, nonporous tape is a better choice for door frames, attic hatches, corners and cracks. Reinforced vinyl rolls are sound choices for door and window stops and the tops/bottoms of window sashes. Door thresholds and bottoms can also be fitted with pliable sealing gaskets.
If you have a fireplace, consider buying an inexpensive inflatable chimney balloon that plugs the airflow from inside your home to the flue. Remember, even small improvements can bring down your energy bills.