Forced ventilation for cooling attics in summer.

The potential for air conditioning energy savings using exhaust fans to cool attics was investigated in six occupied townhouses at Twin Rivers. These houses were compared with similar houses without attic fans. The houses had various levels of instrumentation. Data collected for two summer months in 1977 was the basis for this study. The principal quantities measured were attic and living space temperatures, air conditioner and attic fan usage,together with outside air temperature and solar flux.

The reduction of airborne radon daughter concentration by plateout on an air mixing fan.

Reports a series of experiments made in the U.S. Bureau of Mines radon test chamber to study the effects of condensation nuclei, humidity and turbulence on the rapid deposition or plateout of radon daughter activity on the chamber walls. Under low humidity conditions the presence of a small fan reduced the working level by 41%. The activity was not deposited on the walls by the turbulent flow from the fan but actually became attached to the fan blades. High relative humidity (>80%) totally inhibited this observed effect.

An exhaust fan apparatus for assessing the air leakage characteristics of houses.

Describes portable apparatus used to measure the air leakage of houses. A fan is used to exhaust air from the house and the air flow rate is measured. The air flow rate and corresponding pressure difference across the building can then be used to evaluate the relative air tightness to the house. The fan pressurization test equipment is portable, inexpensive and simple to operate. Describes test procedure and gives a few examples of house characteristic curves.

Air leakage characteristics of low-income housing and the effectiveness of weatherization techniques for reducing air infiltration

Reports measurements of air change rates made on approximately 250 dwellings, occupied by low income households in 14 cities, in all major climatic zones of the United States. Two types of measurements were used : a tracer-gas decay technique using air sample bags and a fan depressurization test that measures induced air exchange rates. Shows that for this group of dwellings natural air infiltration rates have an approximate lognormal distribution.

Infiltration - pressurization correlations: detailed measurements on a California house.

Describes detailed study of infiltration rates measured with a tracer gas and air leakage rates obtained from fan pressurization in small, 3 - bedroom California house as part of a larger study. Finds surface pressure measurements are an essential step in process of finding a correlation between natural air infiltration and air leakage by pressurization. Measurements also show significant duct leakage and air flow between attic, living space and crawl space.

Air tightness of whole buildings

States that aim of research project is to develop a method of testing entire buildings for air infiltration. Suggests apressure method using a powerful fan to pressurize or depressurize the house and measuring air flow through the fan and internal pressure to give a figure for air infiltration.

Testing of houses for air-leakage using a pressure method.

Describes pressure method for testing whole houses for air leakage. States main advantages compared to tracer gas technique are that equipment is inexpensive, easy to handle and so well adapted to routine tests. The house is pressurized using a powerful fan and the flow through the fan is equivalent to the leakage through the building envelope at given pressure. Summarizes measurements made on test houses. and shows use of thermography to detect leaks. suggests use of pressure test to estimate the natural ventilation of a house.

The testing of whole houses for air leakage.

Describes portable air leakage apparatus capable of measuring the air infiltration of whole dwellings directly on site by the pressure method. Main assembly consists of a flow measurement duct and electric fan. Describes test procedure and gives air leakage curves for an ordinary semi-detached house and an experimental house. Finds that doors and windows account for a surprisingly small proportion of total leakage.

Some field experiments with methods of estimating the ventilation rate in animal houses.

Compares methods of calculating ventilation rates in mechanically ventilated animal houses. Ventilation rates in several occupied animal houses were found by 1) measurement of internal to external temperature and moisture differences using a psychrometer;2) measuring decay rates of radioactive krypton as a tracer gas;3) estimating from manufactures rating of fans. Concludes that different methods agree to within the order of 5 or 10% and suggests the use of psychrometer techniques for simplicity.

The prediction of ventilation rates in houses and the implications for energy conservation

Developes mathematical model of air infiltration based on crack flow equations. Describes measurements made on test house. Shows that actual pressure distributions in walls deviate considerably from values in guidebooks. Finds background leakage area of house by pressurizing house with electric fan and measuring pressures. Suggests two distributions for leakage areas. Measures infiltration rate using helium tracer gas, recording temperature and pressure differences. Concludes that comparison between prediction and experimental results is encouraging.