This parameter study with the IMG calculation model for ventilation is an attempt at forming some background for decisions relating to the preparation of a standard in the Netherlands. From the results one can see that air tightness and the heat loss caused by infiltration cannot be considered as a simple linear relationship .
Describes LBL's Mobile Infiltration Test Unit (MITU) which spent the 1980-1981 winter in the field collecting the data required for infiltration modelling. Data included measured infiltration rates, surface pressures, wind velocities, indoor and outdoor temperatures, leakage area and leakage distribution. Comparisons of measured infiltration rates with values calculated from surface pressures (using MITU) have shown no decrease in accuracy when a square-root flow model is used instead of the general power-fit model of leakage.
Gives a summary of the existing types of air infiltration measurement techniques and instrumentation using tracer gases. Describes automated air infiltration instrumentation used by researchers in the US, Canada, the UK, Denmark, Sweden and Switzerland. The equipment can operate in the decay mode, constant flow mode and the constant concentration mode.
In a modern residence with reduced air infiltration, a problem may arise if the fresh air requirement is left to natural leakage. The article discusses this problem, and describes techniques for measuring air leakage and typical results. The contaminants which define the need for ventilation are described and the case for controlled ventilation systems (and possibly heat recovery devices) is made. Areas for further research are recommended.
Measures air infiltration and tightness of Swedish houses using the tracer gas technique and the fan pressurisation technique. Uses a previously developed model correlating air tightness and infiltration to evaluate the performance of Swedish homes. Shows that it is difficult to achieve the recommended minimum ventilation rate according to the Swedish Building Code by relying on natural air infiltration. Most new homes do, however meet the Code's stringent air tightness requirements. A comparison with American houses show that Swedish homes are very tight.
Presents the latest results of air infiltration research in Finland. The aim is to increase the knowledge of the influences of air infiltration on energy consumption, ventilation and indoor climate. Briefly describes the principles of a calculation model for predicting the interconnection between airtightness and air change rate. Describes improvement of air tightness in Finnish buildings, with special attention to construction details. Discusses possibilities of draughtless and controlled fresh air intake through the building envelope.
Reports on a comparative study of residential infiltration as predicted by computer model and as measured in the Mobile Infiltration Test Unit (MITU) as well as in selected test houses, both occupied and unoccupied. Sensitivity analyses were also conducted on each parameter contained in the model against data obtained from MITU.
Reports measurements on air transport through homes made by a committee working a Dutch Standard on Heating Load Calculation similar to DIN 4701, but taking account of air infiltration losses through joints and cracks between glazing, window-frame and facade construction. Describes the measuring method applied. Tables air leakage coefficients c and flow exponents, n ,of a number of flats and single family houses. Also tables c and n values of cracks according to type of construction and material, use of weather strips and measuring institute.
Describes an energy audit being developed at LBL to determine economically optimal retrofits for residential buildings, based on actual, on-site measurements of key indices of the house. Measurements are analyzed on a microprocessor and retrofit combinations compatible with minimum life-cycle cost and occupant preferences are then determined. An important element of this audit is its treatment of infiltration.
Assesses the efficacy of an engineered mechanical ventilation system in controlling indoor humidity in one of the HUDAC Mark XI houses. Develops a mathematical model of the home, which is used to demonstrate the interaction between outdoor humidity, infiltration and ventilation rates, and indoor moisture generation and their influence on indoor humidity levels. Discusses the operating effectiveness of the rotary heat exchanger and the energy saved through its use.
Login