Short answer: Generally Yes
Not so short answer: We think of Insulation as a passive home energy efficiency measure. Passive measures are improvements that help prevent the home from gaining or losing heat. These measures (insulation and air sealing) do not require electricity to operate and work 24 hours a day, 7 days a week, etc…
Active home energy efficiency measures are those mechanically driven measures that operate when the Passive measures have failed. These are things like the HVAC system, whole house fan, and dehumidifiers.
Adding insulation is easily one of the most cost effective ways to reduce your utility bills and increase your comfort levels.
Stuff you need to know!
I should mention that there is a point of diminishing returns for insulation. Each inch of insulation you add above that point will have a lower effective value than the previous inch. The U.S. Dept. of Energy recommends insulating up to R-49 if your using a blown in (loose fill) and we wholeheartedly agree. Once you get to R-49, it’s better to start putting your money into another improvement.
There are many types of insulation out there and tons of manufacturers. Look at the manufacturers instructions and pay close attention to how you install it. A poor installation will result in a poor return on investment.
Common types of insulation include:
Cellulose – a loose fill (blown) insulation, has a better R-value per inch than fiberglass, often made of recycled paper, looks grey.
Fiberglass loose fill – a loose fill (blown) insulation, lower R-value per inch but relatively inexpensive, looks white, pink, or yellow.
Fiberglass batts – comes in rolls or strips, can have a paper backing on one side, great for wall or floor insulation, we do not typically recommend for attics.
Foam – comes in open or closed cell variety, is the best effective R-value per inch of all, air seals as well as insulates, most expensive.
When foaming an attic, the foam is usually installed against the back of the roof. All attic ventilation should be sealed by the foam creating a completely air sealed and insulated space. We recommend removing the old batts or blown insulation if you foam as it makes for a cleaner, easier installation of the foam (it’s expensive enough, don’t take chances on it being installed improperly) and it allows the attic to act as a semi-conditioned space. So depending on the style of home, you will have an entire floor of conditioned storage! If you have a furnace or heat pump in the attic, or your ducts travel through the attic, foam will give an added benefit of taking some of the stress off of your HVAC system and may shorten your return on investment.
Blown Fiberglass and Cellulose is installed on the ceiling or walls. Here in the South Eastern U.S. we don’t see much of a performance difference between the two provided they are installed properly to the correct thickness. We have heard some grumblings from reputable sources that claim to have found that fiberglass performance is drastically reduced in extreme cold conditions. We can’t confirm or deny this since we operate in parts of the country where “y’all and yonder” are acceptable vocabulary. Remember that 10 inches of fiberglass does not equal 10 inches of cellulose. Always use your manufacturers directions. Below is a simple chart for R-value to inch conversions.
When it comes to fiberglass batts, we don’t recommend them for attic ceiling installation for one main reason: They are difficult to get even insulation coverage and most homeowners, and even contractors, don’t do it right. I won’t rant on about the ways it can be messed up (maybe in a later posting) but if you do decide to go this route, give us a call and we will be more than happy to give you a few pointers. Better yet, call us for an Energy Audit so we can talk in person.
One last thing to note: Consider having an Energy Audit done to identify any problems that need to be addressed before adding the insulation. If major air sealing issues exist, it could render your new insulation mostly useless.