English

Examines CO2-controlled ventilation for a variety of buildings. A theoretical study shows that the modification of the ventilation rate which can be obtained by the control of a 2 speed fan or by variation chimney cross-section enables the ventilation rate to be independent of external conditions (wind, temperature) and to produce annual energy savings of the order of 1500-2000 KWhr for a 100m2 house.

Presents a review of work carried out by SCBR concerned with airtightness of buildings and ventilation up to January 1982. Describes important features of building systems and mechanics, ventilation systems and immediate surroundings of importance to ventilation process. Assesses the building physics aspects of ventilation systems for various building categories. Discusses a number of ventilation case studies for detached houses and apartment buildings, and presents existing computer programs for single-cell and multi-cell models.

Leakage measurements of houses are common practice in many countries, partly because they are needed for predicting ventilation rates. To use the measurements in this way it is usually necessary to fit an equation to the measured leakage data, so that the data can be extended into the region of interest. At present, the power-law equation is generally chosen for the curve fit. Considers a new approach using a quadratic equation. Shows that there can be large differences between the 2 equations, so the choice of equation is important.

Describes work carried out by British Gas to establish the magnitude of heat losses from gas-fired boilers arising from natural ventilation through the boiler during its shutdown period. Discusses the general principles of ventilation heat losses to the flue and via the draught diverter and presents data for heat loss decay rates for a range of boilers. Calculates ventilation heat losses for typical boilers. Concludes that for a typical open-flued domestic heating boiler, ventilation heat losses are approx 6% or less of total heat input.

Discusses the ASHRAE Standard 62-1981 "Ventilation for Acceptable Indoor AIr Quality", and extensive field measurements of ventilation. Presents apredictive model for indoor air contaminant concentrations in residences andits verification, along with the effects of several variables. Additional research on the indoor emanation rates of contaminants which are health hazards would enable the prediction of indoor contaminant levels with various control options.

Natural ventilation can be used to reduce cooling loads and increase human comforts in buildings in hot humid climates. Airflow rates are determined by the wind pressure on the faces of the building and the amount of open area. Describes wind pressure coefficient measurements made on 2 buildings at theKaneohe Marine Corps Air Station on the island of Oahu, Hawaii during summer 1982. These full scale measurements will be compared to reduced-scale measurements made of the boundary-layer wind tunnel at the Naval Civil Engineering Laboratory.

A major pathway for loss of conditioned air in east Tennessee homes with externally located HVAC systems is leakage in the ductwork. The effect on infiltration rates, as measured by Freon-12 tracer gas dilution, becomes marked if the central duct fan is operating. Duct fan on and duct fan off measurements of the rate of air exchange gave mean values of 0.41 and 0.78 ach respectively in a total of 31 homes.

Fan pressurization tests on 2 unoccupied houses have been conducted once every 2 weeks for a period of a year to determine the seasonal variation in air tightness. House no.1 was built with more insulation than is required by the local building

Investigates the energy performance of a two storey occupied gas heated house in Ontario Canada by means of steady state and dynamic analyses of measured data. Experimental results were obtained from a monitoring study done on an hourly basis.

Describes an energy efficient hypermarket built in South Wales. Describes energy conserving features, including CO2-controlled ventilation using an infra-red analyser. Briefly discusses problems of installing and calibrating the system.