Retrotec USACE - Manual (Page 295)

F1
Air-leakage is a measure of the unintentional openings in a building. Air leakage
increases heating and cooling costs by allowing energy to escape. Uncontrolled
air leakage will allow excessively humid or dry air to enter, creating low humid-
ity problems under cold outdoor conditions or high humidity problems under
warm humid outdoor conditions. In many cases excessive air leakage will
overpower mechanical systems so that control of temperature, humidity and
outdoor pollutants is impossible under many weather conditions. Energy may
have to be used to extract or to add humidity depending on what is needed.
Air quality may also suffer due to the reduction in the effi ciency of exhaust
systems as they work against powerful natural forces or because these forces
are allowing cooking odors to move through the building. Air quality may also
be degraded by moisture and mold buildup on surfaces resulting in sickness
contributing to chronic health problems in the occupants. Structural elements
of the building may eventually fail due to rust or rot. Finally, excessive air leak-
age will make living conditions uncomfortable and unhealthy.
Appendix F
Measurement of Air-leakage in Large
Buildings
F.1 The Costs of Uncontrolled Air-Leakage
Figure F1. Natural forces affecting building air leakage.