Reviews the ventilation requirements for residential buildings and the recently discovered contaminants of indoor air which will have an influence on the required ventilation rates. Describes methods of measuring air leakage and the rate of air infiltration. Cites work aimed at finding the correlation between air leakage and air infiltration. Outlines the role of heat recovery devices and recommends areas of further research. An appendix reports on a Canadian Mortgage and Housing Association seminar "Controlled ventilation with exhaust air heat recovery for Canadian housing".
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.
It has been shown by Bankvall that forced convection reduces the efficiency of thermal insulation considerably. The reductions can become drastic if the inner skin is not airtight. The leakage around a switch or junction box issufficient. The material in the windproofing skin must be sufficiently impermeable. If complicated joints are to be avoided it must retain its dimensions in varying humidity. If the inner skin is not tight caulking or taping the joints in a plasterboard skin halves the leakage.
Encore-Canada is a Fortran IV computer program which performs a dynamic simulation of energy use on an hourly basis using weather data. The program includes the calculation of air infiltration and solar effects. This report describes the program structure, data preparation, output and procedures for running the program. Gives examples of program applied to a house giving floorplan of the house, input data and program output.
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.
The requirement for better methods of predicting infiltration and natural ventilation rates has been reinforced by the incentive to reduce energy consumption in buildings. Natural ventilation is basically dependent on the effects of wind and temperature difference and on the resistance to airflow through the building. Discusses in detail these factors and highlights areas requiring further study. Briefly illustrates energy savings available by controlling natural ventilation.
Steeply sloping ventilated roofs are preferred for single and two-family houses in West Germany. Notes lack of any scientifically substantiated notions concerning physical laws governing air exchange between ventilated zones and outside air. Describes air flow and heat transfer investigations in a 48 deg. sloping roof. Gives details of roof constructions. Illustrates roof space and distribution of thermocouples and arrangement for injecting tracer gas. Describes experimental procedure. Provides some measurement results. Compares theoretical bases with experimental results.
Describes method for calculating the adventitious ventilation of a building using information from a pressurization test. The method requires a knowledge of the surface pressures on a building, calculated from wind speed and direction, the inside-outside temperature difference, and the distribution and characteristics of openings in the building shell. Applies formulae to threebuildings and finds a great dependence of infiltration on wind direction. Discusses the effect of wind and stack effect, separately and combined.
Presents the results of an energy-efficiency survey of 25 homes located in Saskatoon, Saskatchewan. Insulation levels in the walls, ceilings and basements were measured and the economics of adding insulation to these areas were investigated. Air leakage of the houses was measured using a pressure test and compared with infiltration rates measured using tracer gas in fourhouses.< Concludes that a major portion of the heat loss (30-40%) in the average home was due to excessive infiltration.
Describes an instrument for the measurement of air infiltration into buildings. The instrument indicates the concentration of a tracer gas in the building, by sensing the thermal conductivity of the air-tracer gas mixture.< The instrument, a Katharometer, has not been extensively used because of inherent difficulties. This thesis examines the dificulties. An analysis of the theoretical basis of the instrument is made and the problems created by changes of relative humidity, pressure and temperature are discussed and solutions are suggested.
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