If you talk to an energy-efficiency expert from your local electric cooperative, one of the first things he or she will do is ask about insulation in your home. What type do you have? Is it in the attic, walls and floors? How about the basement or crawl space?
The next question probably will be about air leaks, because homes that aren’t properly insulated often have a lot of air leaks too.
Your home’s “thermal building envelope” separates you from the outside elements. It’s like wearing a coat when it’s cold: If you zip up your coat, you’ll be nice and warm, but if it hangs open, you’re left freezing. By properly sealing the building envelope, creating air barriers and installing insulation, you’ll keep hot air out during summer and cold air out in winter.
Sealing your home’s thermal envelope includes applying caulk and foam to cracks and gaps and correctly installing insulation. If the insulation isn’t properly put in, it won’t be able to do its job. Typically, incorrectly placed insulation leaves gaps between the walls and doors or windows – or where the ceiling meets the walls. If there’s a gap in insulation, heat will get through – into your home during warm-weather months and out of your home during cold ones.
It’s all about air infiltration. Understanding air infiltration is only half the battle. You have to find and stop the invaders. The first step involves putting a “lid” on your home, because heated air rises and will work its way out of the living spaces.
If your local electric cooperative offers home energy audits, call for one soon. Your co-op’s energy advisor can determine if your home needs a blower-door test, one of the best ways of finding out how much air goes in and out of the structure every hour. If a thermal imaging camera is available, the auditor can pinpoint exactly where your home loses air. Typical culprits include the roof and around doors and windows, recessed can lights, attic hatches and pull-down stairs, and unfinished basements or crawl spaces.
Don’t overlook the obvious; check where ceilings and floors meet the walls too. Do you routinely have to clean a cobwebby corner? That’s a good indication of air infiltration, because insects like fresh air.
Use caulk, weather stripping and expanding spray foam to take care of these problem areas. Remember this: Unless you fix air leaks first, adding insulation won’t make your home as comfortable or energy efficient as you want it to be.
Now it’s time for insulation. While loose-fill fiberglass or fiberglass batts in your attic can keep heat from moving into or out of your home, they do little to stop airflow. In fact, if every single joint and crack is not sealed with caulk or expanding foam, your fiberglass batt insulation will do little more than catch dust. Look at your existing insulation around the edges; if it’s black, you’ve got air infiltration – dust being blown through the fiberglass and getting trapped.
Cellulose, made from recycled newspapers and blown in, provides good attic insulation, because it does more to stop airflow. And foam insulation, while the most expensive, also boasts the highest R-value and completely blocks air.
Your co-op energy professional can help you determine the best type of insulation for your home and also help you work out the payback period for your hometightening projects. The bottom line is this: Not only will you be investing in greater long-term comfort in your home, you’ll likely also benefit from significantly reduced cooling and heating bills.