Your Homes Major Systems. A house is a system of interdependent parts which means that the operation of one part will affect the other. When one of the house parts is not functioning properly it will affect the other parts.
The law of heat flow dictates that heat will always flow towards a region of lower temperature. The greater the temperature difference the faster the movement. Heat travels by convection, conduction and radiation. Conduction is the most common and best known method of heat loss.
Forced convection occurs when the movement of liquid or gas is caused by outside forces. For example, a cold wind blowing across a warm outside wall will cause heat to transfer through the wall more quickly.
Approaching the house as a system of interactive parts, the savings mount and we avoid creating health and safety issues. Air sealing and insulating a home reduces the heating and cooling load. A replacement furnace in a sealed and insulated home can be smaller than the existing furnace. The initial price of the smaller unit is lower, and the long-term operating costs will be less. Air sealing and insulating reduce load on heating and cooling appliances, making it possible to downsize equipment. Smaller equipment costs less to purchase and operate.
One common problem with roof/ceiling systems is condensation and staining on the ceiling surface. This is due to moisture condensing on cold surfaces, which is often caused by recessed lights that leak air or are not well insulated. The solution is to make sure that all penetrations through the ceiling are sealed to prevent air flow and insulated to prevent temperature differentials.
Another installation problem is compressing the insulation, which reduces the insulation’s R-value. This often happens when insulation is stuffed behind electrical wiring or piping. The answer here is to cut it to fit the space properly, and to split the fiberglass batts so they maintain their original thickness – and their rated R-value.
Insulating sheathings are rigid insulation boards, typically to 2 inches thick, that have beneficial thermal properties. They provide a way to increase the overall R-value of the wall system, especially in colder climates.
Products that are available are typically made of expanded or extruded polystyrene or from polyisocyanurate foam insulation boards.
With a properly functioning ventilation system, moisture and other pollutants are kept from entering the home. Any pollutant – and moisture is considered a pollutant for the purposes of this discussion – created in the home is transported safely outside through exhaust ventilation and ductwork. However, in many homes, the fans or ducts are loud, leaky, non-existent or otherwise not up to the job. Moisture created within the home condenses on cool building surfaces, both in the living space and in the attic, and causes mould, mildew, poor IAQ, and structural damage.