Managing Moisture
In addition to causing problems with mold and water damage, the passage of water and water vapor through to the interior of the envelope structure is a significant factor in the leakage of thermal energy. Damp building materials allow for the transfer of heat into the house much more quickly, but it also works the other way around; the cool air inside an air-conditioned home draws humidity to condense onto walls, frames or insulating material.
Water vapor control depends on managing the routes by which moisture enters a home: as vapor carried along with air movements, which can be addressed along with airflow and diffusion through permeable building materials, particularly foundations and walls that regularly encounter groundwater or standing rainwater. Especially during rainy winters, it is important to maintain elements of the building that direct rainwater away from the house or prevent it seeping through cracks, including gutters, spouts, caulk and weather-stripping.
Adjusting Airflow
Air flow control includes not only attention to the air quality and ventilation of your home, but also to boost your energy efficiency, especially during seasons that require more heating and cooling. A great deal of the loss of cool air during the summer is due to drafts and air leaks through cracks and other small passages.
This can be a problem in places where parts of the envelope are joined, such as the point where the wall meets the roof or where the edges of doors and windows meet the floor, but it can also appear through the surface of aging or damaged building materials. Attention to and maintenance of the building takes care of the latter, but the former is best addressed by a professional with experience in sealing building envelopes for your local climate.
Controlling Heat Flow
You probably have an intuitive understanding of how heat moves from place to place. A seatbelt buckle sitting in the sun will be heated by the sunlight, the hot air above the stove rises while the cold air from your refrigerator flows down when you open the door, and a fork or a spoon left in a hot dish can transfer that heat from the dish right up to your fingers. The same principles are at work in controlling the movement of heat through a house, but here they work in reverse to prevent the transfer of heat. Reflective materials in the form of radiant barriers are designed prevent heat from radiating from a sun-heated roof to the upper spaces of the house.
Heat transfer through hot or cold air is typically solved by managing air flow. The ideal insulation to install is composed of materials that are poor conductors of heat, so in the winter the warmth will stay inside and in the summer the heat will stay outside instead of passing through your walls, roof and floors into your house. Together these barriers form the thermal envelope, a part of the building envelope that is dedicated to heat flow control and usually concentrated in the upper parts of a house.
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Contact the Net-Zero Energy home builders at Peak One Builders & Restoration to learn more about creating a custom cutting-edge green home. Request a free estimate or call 480-378-0611 now!
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