Heat in your home moves by the following three methods: radiation, conduction and convection. Radiation travels in a straight line in waves of energy. You’ll feel cool in a room that has a cold floor, walls and ceiling. The amount of heat loss from your body in that room depends on the relative temperature of the objects in that room. The colder the floor is (relative to the temperature of your feet), the greater the heat loss from your body will be as you continue to stand there. If the floor, walls and ceiling of that room are relatively warmer than your body temperature, then heat will be radiated to your body from those objects or surfaces.
Heat is a form of energy, and when that heat comes into contact with matter, it makes the atoms and molecules move. When atoms and molecules move, they collide with other atoms and molecules and make them move, too. This movement transfers heat through matter.
Convection is the principle of warm rising and cold air falling. The transfer of energy by warming the air next to a warm object and then moving that warm air. As warm air rises it warms the air above and continues to rise. Some older furnaces used gravity to move heat throughout the house.
Air movement moves 98% of all water vapour in building cavities. Air will always move from a high pressure area to low pressure area by the easiest route available. Proper air sealing of a house will prevent this transfer of moisture into your cavities, voids and insulation.
The Dew Point is the temperature at which warm moist air will actually condense into water. In Ontario this normally occurs in the winter when warm moist air travels through your walls to the cold outside. When the warm moist air reaches the cold air, the Dew Point, it condenses into water, which will happen somewhere in your wall or ceiling insulation.
Installing a vapour barrier will prevent the movement of moisture when the warm air is travelling through your walls and ceilings to the exterior. Remember heat goes to cold, the vapour barrier ensures that the moisture does not go with it. The moist warm air will produce water at the Dew Point creating all kinds of problems in your attic or walls.
Your homes duct work needs to be sealed and insulated, especially if the ducts pass through an unconditioned, unheated space, such as an attic. Returns ducts should be sealed, too. Air sealing is important.
Some foams are filled with special gases that provide additional resistance to heat flow. Using a Thermal Imaging camera during a home inspection will allow your professional home inspector to locate any missing vapour barriers or insulation. Most home inspectors offer this service for FREE.
When buying a home in the Barrie area call Barrie’s Professional Inspection Services and how they can protect your investment. Barrie Home Owners should visit Barrie’s Home Owner Tips and Advice Blog