English

Conducts series of tunnel tests to examine ways in which wind influence air infiltration energy losses in housing. Develops qualitative model for air infiltration based upon a linear relationship between air flow and pressure difference across walls and roof surfaces. Tests a variety of wind-house orientations with the model. Assesses and compares sheltering effects provided by solid fences, adjacent houses and tall evergreen trees. NOTES See also later study by Mattingly et al. abstract no.187

Outlines basic requirements for a fresh air supply to a dwelling, which include health, comfort and air for combustion appliances. Discusses feasibility of achieving these requirements by natural and mechanical means.

Points out that ventilation heat loss can account for 50% of total loss in a well-ventilated house. Presents analysis of mechanics of natural ventilation. Describes computer-based model developed by British Gas Corporation for predicting ventilation patterns in houses. Uses calculations applying the method to illustrate basic reasons why natural ventilation is likely to cause problems in heating well-insulated dwellings. Discusses these problems in detail. Treats how ventilation could affect sizing of appliances and indoor thermal environment.

Claims procedures for design of ventilation and air flow systems are energy wasteful. Cause lies in their methods and technical bases and influence of other factors entering into final systems choice (particularly economics). Discusses outside air requirements. Concludes ventilation rate can be lowered 45% to 50% if higher humidities are used. Proposes new standards based on fact that ventilation rate is independent of air space per person. Analyses air distribution systems and sub-systems in terms of minimum energy requirements.

Reconsiders semi-empirical equations derived from earlier laboratory investigation of flow through cracks. Proposes revised method of application. States equations offer improved technique for estimating open areas of room components. Presents supportive experimental results. Demonstrates implications of the equations regarding scale effect for full-scale and model-scale situations. Presents some results of ventilation rate measurements at model scale to illustrate effects of scale and wind turbulence, flow characteristics of scale model windows and of simple circular holes.

Treats 4 mechanisms of building heat exchange with the environment and their effect on overall energy consumption: 1) air infiltration and exfiltration, pressure distributions and gradients and resulting mass transfer at building surfaces; 2) influence on surface heat transmission of turbulent mixing of air close to building surface and mechanisms causing this mixing; 3) how air circulation around buildings strongly affects air conditioning cooling towers and how incorrect location of ventilation inlets and exhausts can reduce thermal efficiencies of cooling equipment and increase fan power

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.

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.