Gives results from fiel trials of the performance of various mechanical ventilation systems. Carries out measurements in buildings built during the seventies, using the tracer gas decay technique with N2O. Tests 3 cases:< 1. Air supplied only through register above door< 2. Air supplied both through register and the slot under the door< 3. Air supplied only through slot under the door.
Reports on 2 methods of measuring ventilation rates in the 8-storey San Francisco Social Services Building, using occupant-generated CO2 as a tracer gas. Measures CO2 concentration at regular intervals on the first floor using an infra-red gas detector. Uses the tracer gas decay method and the constant concentration (integral) method to determine ventilation rates. Finds that the CO2 decay method compares favourably with both SF6 tracer gas measurements and with air-flow measurements in the ducts.
Outlines a method for measuring air infiltration using the tracer gas decay technique. SF6 is introduced into a building, and once it is well mixed, container samples of air (in this case plastic bottles) taken over a period of time are analy
Compares the air change rates measured using the decay method with several different tracer gases. Tracer gas measurements were conducted in a tightly sealed room where constant air leakage rates were maintained using an exhaust fan. Tracer gases investigated were CH4, CO, CO2, N2O and SF6. Agreement between tracer gas measurements and measured flow rates of the exhaust fan was very good for CH4, CO and N2O. The agreement was also satisfactory for CO2 and SF6, but the scatter in tracer gas data was much greater then it was for the other three gases.
Uses a multi-channel infra-red gas analyser to measure nitrous oxide tracer gas concentration at six points round a house. Combines concentrations to give overall house ventilation rates and to estimate the air exchange between individual rooms. The gas analyser is also used to measure air movement between the house and its roof (with 5 sampling points in the house and one in the roof). Results show that typically 20-30% of the air that enters a houseleaves via the roof space through gaps in the ceiling.
Compares the air change rates measured with SF6 and CO2 using the tracer gas decay technique and the fan extraction method over a wide variety of test chamber sizes and mixing systems. Shows that the conventional air handling orportable floor fans can provide adequate mixing for SF6 tracer gas decay measurements of infiltration. Warns that the mixing operation may become the dominant driving force of infiltration during calm climatic conditions. Finds that +-0.08 ach/h is a reasonable measure of experimental error at the 95%confidence level using SF6 as the tracer gas.
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.
Describes a technique developed for measuring air flows between internal spaces of houses. Involves using a portable gas chromatograph to monitor the concentrations of three tracer gases released in three distinct zones within the building envelope. Using the results of each measurement, which takes approximately two hours, the ventilation rate of each zone can be calculated along with the interconnecting air flow. Presents the tracer gas equations involved, and includes an account of the experimental method and the practical difficulties encountered.
Gives measurements of the ventilation as well as the temperature efficiency of mechanical supply and exhaust systems (balanced systems). The ventilation efficiency is a measure of the performance of providing air in the occupied zone and is also an indicator of the air quality. The temperature efficiency is a measure of the system's capability of supplying heat in the occupied zone. Monitors ventilation efficiencies by adopting tracer decay techniques and the temperature efficiencies by measuring the stationary temperatures.
Reports on continuous energy measurements carried out in 6 detached single-family, low-energy houses in Copenhagen. Describes a few typical construction details to illustrate solutions to the problem of cold bridges, and to demonstrate ways of obtaining airtight constructions. Measures air change rate using tracer gas decay method and pressurisation and suction tests. Works out total heat loss for a period when ventilation systems are sealed and the houses heated by electric resistance heaters.
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