Whether you live in a warm climate, where the air conditioner or fans run a lot, or a colder climate, where it’s the furnace or woodstove running, insulation is a MUST!
Insulation is your first line of defense against high energy bills. The Department of Energy estimates that a properly insulated attic can shave 10 to 50 percent off your heating bill. It works the opposite way for warm climates – in summer, it helps stabilize your house’s indoor temps to keep cooling needs in check.
The attic is one of the most overlooked areas of insulation, with many dwellings showing a severe lack of proper depth. How much insulation does your attic need? That will depend upon which zone you live in.
Which type of insulation do I need? The choices are varied, but all can be highly effective if installed properly. Do your homework and decide what method is right for you!
Batts: These are large pieces of insulation that hold together because they’re made of long, interweaving fibers with adhesive binders. The two kinds of batts you’re most likely to encounter are fiberglass and cotton. In terms of their insulating quality, they’re pretty much equivalent. Cotton batts, though, are ‘cool’ because they’re made of recycled blue jeans.
The problem with batts, however, is that they don’t always work well filling oddly shaped spaces. For the best performance, an insulation material needs to fill the whole space, with no gaps, voids, compression, or incompletely filled areas. Batts are about the worst you can do here.
Blown: A better choice is insulation that comes in smaller chunks. The installer holds a large hose and blows the chunks into the attic. A large machine outside churns the chunks and uses air to blow them up through the hose.
The two main choices here are fiberglass and cellulose, and each has its advantages and disadvantages. They both insulate about the same, though, with R-values in the 3 to 4 per inch range. Cellulose comes from recycled newspapers. Fiberglass comes from sand. It’s a common insulation material that works much better in the blown form than in batts.
The third major type of insulation is spray foam. There are two types of spray foam – open cell and closed cell. Each has its pros and cons, as well as its own set of adherents who will tell you never to use the other type. That’s an article for another day, however.
The main advantage of spray foam is that it allows you to move the building envelope – the boundary between conditioned and unconditioned space – from the attic floor to the roofline. If you’ve got your HVAC system and ducts in the attic, then moving the envelope to the roofline can be a good thing. In a new home, spraying foam in the roofline can bring the ducts inside the envelope without having to redesign the system and house.
Benefits of proper insulation in the attic:
- Dramatically lowered utility costs.
2. Extended service life of both air conditioners and furnaces.
3. Reduced fuel costs also mean less of a carbon “footprint” and less contribution to greenhouse gases.
If you’ve been putting off that attic insulating, now is the time. The savings it could represent over 10 years could easily pay for itself, not to mention the comfort in your home.