attic

A survey of twenty residential buildings was conducted to observe the impact of ventilation strategies on moisture· accumulation in attics. The objectives of the survey were to record attic lumber moisture content levels over a period of one year and to assess the ventilation characteristics of the attics in order to account for the recorded moisture levels. The sample homes represented a range of ages, construction types and attic venting formats. Five of the houses were located in a coastal climate. Two test protocols, developed specifically for this project. were applied to the sample.

The idea that intend temperatures can be reduced by ventilating the air-space between the ceiling and the roof (the attic) of a house, is widely acknowledged by Civil Engineers and Architects. This phenomenon was evaluated through three softwares (CASAMO-CLIM, COMFIE and SPIEL) which were designed for the analysis of the thermal performance of buildings, by comparing the results of all three.

The ventilation of a Swedish single family house is investigated by means of tracer gas and pressurization techniques. The ventilation flow plays an important role in this house as it enters through a dynamic loft insulation and exits via the crawl space. This design is said to give preheated and clean supply air, warm floors and good energy efficiency. But to meet these promises, it is essential that the air really flows in the intended paths. A single tracer gas technique is used to determine the air flow rates.