measurement technique

Describes the use of SF6 tracer gas measurement techniques employed in airtightness and ventilation research at Princeton in terraced housing. Notes use of measurement results for constructing models describing the total adventitious ventilation in a house. Refers also to similar techniques used in research at Berkeley in single family dwellings.

The uncertainty of measurement results of air velocities in air-conditioned rooms generally is very high. A considerable part of the measurement errors are caused by the evaluation methods. It is shown that the accuracy of results can be ameliorated by using suitable statistical methods without increasing the effort. In this case binomial distribution gives better results thenGaussian distribution. To optimize the duration of measurements the most favorable reading interval must be determined. This time interval can be defined by the autocorrelation function of air velocity.

Discusses standards and testing procedures for window air and water tightness. Describes apparatus used at the Technical Centre for Wood. Gives brief results of airtightness tests on 70 windows of different types subjected to a pressure of 10mm of water and of water tightness tests on 40 windows. Describes a test wall, designed to enable "hurricane" tests to be made. Appendices giveinformation on precipitation in France and discuss water-proofing products.

The heat transfer characteristics of a window system are generally specified by three static measurements; winter U-value, shading coefficient and air infiltration. Outlines methods for measuring these three values. Describes the mobile window test facility, designed to test windows under real weather conditions. The facility consists of a portable test building which can rotate about a central point.The building contains four test rooms with a guard room on each end. Describes the instrumentation and test methods. Construction of the MoWiTT facility is planned for late 1980.

Describes methods used at ECRC for measuring the ventilation rate in houses. Two tracer gas methods are used, the decay method and the constant concentration method. Measurements have been made using both nitrous oxide and carbon dioxide as tracer gases. Also describes test of air leakage made by pressurizing the entire house. Gives for each method a detailed description of the measurement technique.

Describes different goals of air leakage measurement with corresponding measuring methods. Discusses results and experience from measurements carried out with the stationary overpressure method and the non-stationary tracer gas method. Adds working diagrams. Pleads for further standardisation of thespecific equivalent leak opening (SELO) especially of temperature on which it is based. Gives numerical example for calculating the lower limit of admissible non-tightness of cold rooms.

Describes the first stage of an investigation designed to simulate in a wind tunnel the full scale wind pressure measurements made by the Building Research Establishment on the Aylesbury test house. Describes in detail the wind tunnel, instrumentation, measurement techniques and experimental procedures. Discusses the problems of simulating natural wind.< Discusses the results of measurements of mean pressure coefficients. Compares results with full scale measurements and results of a wind tunnel simulation made at the University of Bristol.

Describes a procedure for measuring the transmission and ventilation heat losses of unoccupied houses and their solar heat gain. Internal temperatures, ventilation rate and weather data are measured. An infrared camera is used todetect both local areas of high transmission heat loss and, together with a slight pressurization of the house, air leakage paths. Gives graphs for calculating the effective solar heating. Notes that results obtained from the tests depend very much on the skill of the people operating the equipment.

Describes some of the problems encountered when the full-scale wind pressure measuring system was set up in an experimental building at the University of Hong Kong. Discusses effects such as excessive damping caused by the air trapped in the pressure- balancing tubings, and the interference between transducers. Describes modifications of the measuring system to overcome these problems.