Wind and trees: air infiltration effects on energy in housing

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

Ventilation: design considerations

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.

Natural ventilation in well-insulated houses.

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.

Energy savings due to changes in design of ventilation and air flow systems

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.

Crack flow equations and scale effect

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.

Air change rates in buildings. Byginingers luftskifte

Summarises results of research project comprising survey of air tightness and natural air change rates in various types of residential building. Briefly describes equipment for pressurization tests and tracer gas measurements. Compares properties, range of measurement and cost of 5 different tracer gases. Provides some results from measurements in 53 single family houses and 28 flats. 9 of tested dwellings had their tightness improved and supplementary measurements made.

Economic ventilation of single family houses. Ekonomisk ventilation i smahus.

Outlines necessary ventilation rates for an occupied room. Discusses natural ventilation of a room through openings in the ceiling. Discusses natural draught ventilation for single family houses, combined natural draught and mechanical ventilation, mechanical fresh air ventilation based on a central duct, fortuitous ventilation caused by air infiltration and leakage. Compares natural and mechanical ventilation. Considers supplyair systems for single family houses, warm air heating and possibilities for heat recovery.

The effect of wind on energy consumption in buildings.

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

Air infiltration in high rise buildings Infiltrace vzduchu ve vyskovych budovach.

Provides results of measurements of air infiltration and natural air movement in 3 high rise buildings (flats, university, offices). Gives measurements of pressure differences at doors and windows and between windward and leeward sides of buildings. Determines air flow through selected rooms by CO2 concentration measurements. States that data have contributed information towards new edition of Czechoslovak standard CSN 06 0210 concerning infiltration heat loss calculation in buildings.

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