attic

Three identical houses in Houston, Texas were extensively instrumented for measuring their air conditioner energy consumption and ceiling and duct heat-gain rates. Comparative tests were conducted to investigate differences in house performance due to increased attic ventilation. The performances of a roof-mounted power ventilator, a ridge vent, and wind-driven turbines were compared to the performance of soffit venting meeting the requirements of the HUD Minimum Property Standards.

Contains articles on rain penetration and moisture damage in residential construction, moisture sources in houses, control of surface and concealed condensation, and ventilation of houses. Illustrates the various types of condensation problems that may occur, explains the active processes involved in some of these problems and discusses in detail the principal factors surrounding these phenomena i.e. sources of moisture, choice of construction detail, and current ventilation practice.

In this paper ventilation of attics and crawl-spaces is investigated theoretically. Ventilation rates and temperatures of the spaces are calculated by means of flow balance procedures. Flow characteristics of ventilators and openings for attics and crawl-spaces are far from well known, so a laboratory investigation on pressure drops across such devices was undertaken and reported in the paper. As convective flows from the heated part of a houseinto a colder, ventilated space can create moisture problems this situation has been investigated extensively.

The manufacturing procedures and performance of a building air infiltration kit consisting of miniature passive perfluorocarbon tracer permeation sources and passive adsorption tube samplers are described. 

Moisture enters an attic both from the house and from the ventilation air. It has been assumed that when the roof sheathing temperature cools below the attic air dew point, condensation occurs on the roof sheathing. If this were true, then increased attic insulation levels would require increased attic ventilation rates. Results from an experimental study are presented which show that in fact the roof sheathing is in dynamic equilibrium with moisture in the attic air, and that several hundred pounds of water can be stored in the attic wood without ill effects.

Air leaks which can bypass attic insulation in US wood framed houses are identified. Examples of heat loss paths include gaps at the entry of plumbing, heating or cooling ducts and electrics gaps around flues, and trapdoors. Remedial measures discussed include stuffing gaps with fibreglass, weatherstripping, taping polythene sheet over gaps, sealing and insulating ducts, and covering ceiling fan vents during the winter.

A small test house having a pitched roof/ventilated attic was installed in a high bay environmental chamber. The test house and its attic were extensively instrumented for measuring heat and moisture transfer. The test house was exposed to a ser

Studies moisture conditions in homes in 2 studies. In one study, 17 homes in 4 states were probed in mid-March 1977, and all moisture content levels were found to be within the acceptable range of equilibrium moisture contents. Inanother study, collects data for 16 homes in north-central Utah, Southern Alabama, Northern Ohio and central Maryland. Makes measurements in each home for approx 1 week in the summer and 1 week in the winter. All homes have well-ventilated attics.

Describes a series of experiments performed on a residential attic under controlled laboratory experiments to obtain a better understanding of attics and attic insulation. Studies type and level of ceiling insulation, mean temperature and heat flow direction (summer v winter) and ventilation rate Describes the experimental set-up and the weather conditions simulated. Gives details of the mathematical models of thermal performance that are developed from finite difference analyses of the ceiling-insulation system. Compares experimental results with the predictions of these models.

Investigates the effect of energy-saving measures by selecting a large number of multi-family and single-family swedish houses where such measures have been carried out. Energy saving methods include insulation of external walls and attics, triple glazing windows, and installation of radiator thermostatic valves. Concludes that these modifications have, in average, led to anticipated savings when they have been modified individually. Also considers moisture problems arising in retrofitted houses, and the effectiveness of different types of weatherstrips in energy conservation.