Insulation in the roof and walls is clearly beneficial for its ability to reduce heating and cooling losses and costs. The savings achieved by reducing heat transfer by conduction justifies the cost of adequate insulation.
But don’t forget that convection is another source of heat transfer when air moves between two spaces. Minimizing or controlling losses via convection is desirable but requires more consideration. Adequate outside air is necessary for breathing, and sufficient air transfer is required to ventilate other gases and odors from interior spaces.
Most homes are so leaky that there is plenty of opportunity for air to intrude and be enough for the occupants. However, as structures become more air-tight and interior materials become more synthetic, there is the possibility that the indoor air quality is compromised.
Garage insulation may seem optional, when other more obvious home improvements vie for limited dollars. But with rising fuel costs, it’s a good idea to take a close look at all the ways it could make good sense, and good cents, to insulate all or part of the garage.
This is particularly true for the attached garage. Insulation of common walls shared by the garage and the main living space is obviously of great importance. This includes the ceiling of the garage if there is living space above. All too often, there is great heat loss or gain through these walls, because the air in the garage can rise or fall to temperatures that are even more extreme than those outside. It is therefore almost more important to insulate the walls between the garage and the house as it is to insulate the house’s exterior walls.