decay rate

Describes detailed experimental analysis of the low energy Plainevaux House with regard to:< 1. Air infiltration, measured by the decay rate of CO2 tracer gas< 2. Air tightness, measured by the fan pressurization technique< 3. The evolution of inside temperature in a period of no-heating< 4. The corresponding air contamination.

Measures the air infiltration in individual rooms of a one-storey airtight house, using a special tracer gas measurement technique. Concludes that the overall ventilation rate was very low for the test house, although it had mechanical ventilation (exhaust fan). States that the best way of getting adequate ventilation is to install a ventilation system with built-in routes where fresh air can enter the building. This should either be balanced ventilation system or an exhaust fan system with special vents to the outside for supplying fresh air.

Presents new data acquired by experiments on the ventilation rates and the indoor air pollution caused by combustion in the dining-kitchens of sound-insulated houses. Ventilation rates were measured by means of tracer gas decay, using CO2 and CO as the tracer gases. Indoor air pollution was estimated from the elevation of CO and CO2 levels, and the effect of supply or exhaust fan systems on the control of ventilation was deduced from the level of air pollution and ventilation rates.

Presents results of measurements of ventilation rates in the SEGAS test house. Describes the house and its heating and mechanical ventilation systems. Measurements of ventilation rates were made using helium as a tracer gas. Tests were made both with the house sealed to block obvious paths of infiltration and with it unsealed. Tests were also made with the house mechanically ventilated and with supply and extract systems working. Presents results of tests and examines the effect of variation in mean wind speed on ventilation rates.

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.

Reports heat loss measurements made in an unoccupied house at Kenmay, Scotland. Gives constructional details of this well-insulated house. Reports measurements of energy and temperatures over two heating seasons and short term measurements of ventilation by tracer gas decay method. Finds natural ventilation rate of 0.25 air changes/hour and attributes this to low windspeeds. Compares calculated value of fabric heat loss with measured value and finds good agreement. Finds type of system used, either convective or fan heating has not affected the measured heat loss.

The local ventilation efficiency of a mechanical ventilation system may in general terms be defined as "providing air in those parts of a room where it is required". In this paper different definitions of the local ventilation efficiency and methods for measuring it are discussed. Presents results from measurements of ventilation efficiency. A test room was mechanically ventilated and nitrous oxide used as a tracer gas. A number of sensors were placed in the room with the aim of determining the variations in the air change rates within the room.

Reports measurements of air leakage rates in the four energy-conservation research houses using the fan pressurization method. One of the houses is standard for the area and the other three houses have added insulation and vapour barriers. One house has a heat pump and one an air-to-air solar heating system. Air infiltration rates were measured in two of the houses using CO2 as a tracer gas. Discusses results and compares tracer gas with pressurization tests.

Discusses the tracer dilution method for measuring air change rates. The technique entails introducing small amounts of tracer gas into a building and measuring the rate of change in tracer concentration. Describes the method and compares different tracer gases. Outline ways of obtaining an estimate of the air infiltration from experimental data. An appendix discusses the errors in the procedure.

The Alberta Home Heating Research Facility consists of six uninhabited wood frame single storey modules with full basements. Describes the modules which are designed to test domestic heating strategies in a northern climate. Reports a series of preliminary measurements of infiltration rate using SF6 as a tracer gas and measuring the rate of decay of the gas. Future studies are planned using SF6 in constant concentration.