The nature and magnitude of the problem: building sources vs ventilation.

Introductory talk on the indoor air quality problem. Compares risk of radon pollution in houses to the risks of smoking tobacco, and gives a definition of levels of concern. Mentions filtering of indoor air by means of an air-to-air heat exchanger, the interaction between ventilation and sources, e.g. unvented combustion heaters and carbon dioxide emissions; measurements of nitrogen dioxide are compared, and formaldehyde concentrations in 28 different commercial buildings.

Design of low cost ventilation air heat exchangers.

The design of a low cost ventilation air heat exchanger which utilizes plastic sheets as the heat transfer surface is presented. Laboratory tests on such acounter flow heat exchanger have demonstrated very high values of overall heat transfer coefficients, heat exchanger effectiveness, and temperature recovery when the flow is laminar and buoyancy effects assist the heat transfer. The costs of such heat exchangers would make them attractive for many building applications.

Air-to-air heat exchangers.

Factsheet discusses types of air-to-air heat exchangers, their advantages and disadvantages, installation details, and how to select an air-to-air heat exchanger that is appropriate. Sections include how an air-to-air heat exchanger works, materials used for partitions, installation, condensation and frost removal, controls, maintenance, selecting a heat exchanger, and how much energy will be saved.

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