attic

During the cooling season, heat transfer from the attic into the conditioned space of a residence can represent a significant portion of the total envelope heat transfer. Radiant barriers are one method used to reduce this heat transfer. A quasi-steady-state model was developed or predicting attic heat transfer in residences with radiant barrier systems. The model was used to estimate the reduction in cooling load that would occur with a radiant barrier and to identify important construction and environmental parameters that influence this cooling load reduction.

The attic space of most residential buildings is well insulated from the house below, and therefore experiences extreme temperature conditions on seasonal and diurnal cycles. This can cause moisture entering the attic through the ceiling from the house, or through other leaks from outside, to accumulate in or on interior wood surfaces. This moisture accumulation leads to structural degradation and the growth of micro-organisms.

The ventilation of an attic is critical in estimating heating and cooling loads for buildings because the air temperature in the attic is highly sensitive to ventilation rate. In addition, attic ventilation is an important parameter for determining moisture accumulation in attic spaces that can lead to structural damage and reduced insulation effectiveness. Historically, attic venting has been a common method for controlling attic temperature and moisture, but there have been no calculation techniques available to determine attic ventilation rates.