By Kevin Pink, Customer Service and Marketing Assistant

Why are some houses cold and drafty in the winter and sweltering in the summer, while others stay at a comfortable temperature year-round? The answer to that question is simple, and it can save you a lot of money. I’m talking about insulation!

What is insulation?

Insulation is any substance that resists the transfer of heat energy. Solid substances such as wool and fluids like still air are strong insulators, but merely being a good insulator is not enough. Insulation is at its most effective when it is applied to the proper places. But where should you deploy insulation to achieve its maximum effect? To determine that, you need to know how heat works.

Heat (thermal energy) travels from areas of warm to areas of cold until it is evenly-distributed. When a warm substance (like your walls, for example) is exposed to cold (like the air outside), heat moves through that warm substance and escapes into the cold through a process called conduction. When air is heated, the excited molecules rise and cooler molecules fall. This movement is called convection, and if left unchecked, it causes the warm air in your home to rise up to your colder attic. Properly-installed insulation is a great way to stop conduction and convection in their tracks.

What kinds of insulation exist?

insul1opens IMAGE file Blanket insulation is typically made of wool, fiberglass, and rock wool. It generally comes by the roll, and insulates by trapping air pockets between their fibers. Rolls of this insulation can be cut to fit between wall and floor studs. This is an excellent form of insulation for attic floors. Blanket insulation also comes in batts, which are basically just pre-cut sections of the same insulation. Blanket insulation is most effective when it is several inches thick, but care should be taken not to compress it, which squeezes out the air pockets.

insul2opens IMAGE file Loose fill insulation is blown into spaces with a special machine. It is often used in cavities in which it would be difficult to install blanket insulation. Loose fill insulation, typically cellulose or fiberglass, is often blown into walls through small holes. The pieces of cellulose or fiberglass pack the space, somewhat like filling a bag with dried leaves, leaving enough room for any ductwork or piping but filling in closely around it. It is also excellent for filling gaps and voids in other insulation. It is often on top of blanket insulation on attic floors to provided additional heat resistance. Cellulose is often primarily made of recycled newspaper, making it a greener option.

 insul3opens IMAGE file Rigid Insulation is a variety of foam board. It offers a significant insulating ability in comparatively-thin boards. Rigid insulation is often used on the exterior of a home or on unfinished walls, such as in basements. It is also sometimes used in floors and ceilings. Like blanket insulation, rigid insulation uses the power of trapped air to resist heat transfer. It is often attached directly to a wall or ceiling with screws or glue, then covered with additional spray foam insulation.

At this point, you may be thinking “That’s great, but how am I going to pay for all of that insulation?” The Mass Save program offers to pay up to 75% of the costs of qualified insulation work up to $2,000. If you need to borrow money to pay for weatherization improvements, you may qualify for the 0% interest HEAT Loan, also offered by Mass Save. Your first step to accessing all of these programs and incentives is scheduling a no-cost Home Energy Assessment through Mass Save. Insulate while the sun shines this summer and you’ll have a warmer, less-expensive winter!