pressurization

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.

Describes methods of measuring the air tightness of whole buildings. Outlines three tracer gas methods; constant concentration; decreasing concentration and constant emission. Describes pressurisation method. Describes measuring equipment and test procedure and discusses calculation of ventilation rateand error magnitudes. Gives brief summary of measured results and an appendix contains a print-out of data on the airtightness of houses.

The overall air leakage of high-rise buildings cannot be measured using a full pressure method because of the large volume involved. Describes a method of conducting small-scale pressurization tests on the exterior walls of apartments in multi-storey buildings. Gives results of measurements in a test building. compares direct method with values obtained by summing the air leakage of individual components. Finds good agreement. Concludes that floor/wall joints, windows and window sills are the three major air leakage sources in exterior walls.

Reports tests made on a mobile home to evaluate its thermal performance. Describes home, instrumentation and test procedure. Gives energy consumption as a function of indoor-outdoor temperature difference. Finds that oversized heating plant resulted in low seasonal operating efficiency. Air infiltration was measured using pressurization technique and SF6 as a tracer gas. The latter showed that operation of the heating plant induced higher air infiltration rates. Reports thermographic survey of interior surfaces which showed air paths formed by wrinkles in the surface insulation.

Describes research project to find air leakage values of walls of elevator and stair shafts in order to use these values in the design of pressurization systems. Describes method of test and gives results. Concludes that leakage rates for walls of elevator shafts constructed of masonary units are higher than those of cast-in-place concrete. Variations in the leakage of stair shafts could not be related to the type of wall construction but probably depended on the workmanship in sealing crack openings.

Describes a simple pressure method for measuring the air tightness of small buildings. It measures the leakage rate from all apertures in the external envelope simultaneously, from which total leakage area of openings could be inferred. Site measurements have shown that obvious sources of leakage like doors and windows account for only the minor part of total leakage area in the average dwelling. Results from 25 dwellings show no trend of leakage area per unit of gross floor area.

Discusses ways of increasing accuracy and thoroughness of energy audits of buildings by use of specialized instruments and improved audit techniques. States air infiltration measurements are key item in audit procedure. Describes 'house doctor' kitwhich with records of past energy usage, knowledge of prevailing weather and a questionnaire are used to establish the energy signature of a house. The kit includes blower door, infrared camera, temperature probes and appliance consumption meter. Describes simple tracer gas method using sulphur hexafluoride collected in sample bottles.

Describes the two major methods of measuring air leakage in buildings; the tracer gas method and the pressure method. The three ways of using tracer gas are with decreasing gas concentration, constant gas concentration, and with constant gasrelease. In Sweden nitrous oxide is normally used. The results of the tracer gas method may depend on the weather at the time of measurement. The pressure method is fast and accurate, but only gives the total leakage through the building. Local differences can be detected by use of infrared photography.

Reports two-year programme to evaluate the effect of air infiltration on the heating needs of 29 electrically heated homes. Air-change rates before and after retrofitting tominimize infiltration were measured by a pressure method and heat energy consumption and occupancy effects were monitored. Thirty similar homes were also tested for infiltration and retained as controls.< Describes the retrofit methods, their effect upon the induced air infiltration, the other data which are being collected, and the data analyses which are expected at the completion of the programme.

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.