Reviews mechanism of natural ventilation. Provides mathematical expressions for wind pressure distribution, stack effect, and air flows. Treats air leakage component's characteristics, both individually and connected in series or parallel. Employs model simplification to 1 and 2 Junctions. Illustrates a 1-Junction model calculation. Finds calculated and measured values agreed well for a large factory hall.
Discusses oxygen requirements and moisture emission of individuals and generation of CO2, odours, and aerosols in inhabited rooms. Treats calculation of hygienically necessary air flow rates. Notes characteristics of continuous andintermittent ventilation, whereby additional outside air is discharged into a room at set intervals when continuous airflow rate falls below hygiene requirements. Compares hygienically adequate, continuous ventilation with intermittent ventilation by calculating hygienically-necessary outside air flowrate using a mathematical mode.
Describes new calculation procedure which forms a basis for 1978 draft in German Standard DIN 4701 "Building heat demand calculation". Defines infiltration heat loss. Examines previous German standard calculation procedure. Outlines basis of natural air flows in buildings in some detail including effect of air pressure and stack effects. Treats pressure distributions affected by wind and stack effects. Describes mass flow balances for 2 building types and infiltration heat losses.
Argues that heat losses and ingress of cold air through factory doors are best reduced by the use of air locks and air curtains. Derives equations defining heat losses through unprotected doors. Illustrates air balance of an industrial shed. Diagrammatically illustrates in a graph relation of heat losses to size of entrance. Treats methods and effectiveness of reducing heat losses by air curtains and air locks respectively. Recommends unheated air locks except for circumstances dictating use of air curtains.
Notes importance of air infiltration for total energy budget of a structure and indoor-outdoor pollution. Treats briefly significant energy savings which can be achieved by reducing infiltration rates in buildings. Describes in detail tracer dilution method of determining infiltration rates, which entails measurement of the logarithmic dilution rate of a tracer gas concentration with respect to time.
Expresses air infiltration rate measured using tracer gas in 2 similar town houses in terms of wind speed, wind direction, indoor-outdoor temperature difference, average rate of boiler firing and fraction of time that doors are open. Method yielded reproducible rates of air infiltration within 0.1 air exchanges per hour in any single one-week run once outside temperature, wind speed and wind direction were allowed for. States results partly reveal set of physical principles determining house air exchange rates which are so far poorly understood.
Sets out simplified analysis of thermal load imposed by infiltration of cold outside air into interior of heated building as function of prevailing wind speed and difference between internal and external temperatures. Treats infiltration loss, structure loss, effect of wind speed on loss. Summarises these values in tables. Concludes incidence of wind speeds in excess of those used for calculation of heat losses at design condition can have a significant effect on internal temperatures. Notes implications for non-attainment of design temperatures in intermittently heated buildings.
Ventilation losses account for approximately 50% of heat consumed by a building. Treats characteristics of leakage generally. Estimates that decrease of ventilation of building stock in Finland by 0.1 air changes per hour would save about 100 million f marks annually. Provides practical instructions for controlling building leakage rates.
Outlines some research by social psychologists to induce people to reduce residential energy consumption. Results indicate that summer electricity consumption could be predicted from energy-related attitudes. Personal comfort and health concerns were the best predictors of consumption. Treats experimental examination in 3 separate studies of psychologically derived techniques to reduce summer electricity consumption. Gives results and conclusions.
Estimates of air infiltration in houses based on tracer gas measurements have usually assumed house is a single perfect mixing chamber with incoming air instantaneously and uniformly diffused to all parts of the interior. Points out that in reality some parts of the house - basement or rooms with doors closed - exchange air only very slowly with other parts so that actual mixing is far from instantaneous. Presents theory and mathematics necessary to apply tracer gas method to buildings of many chambers.
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