"Problems related to excess moisture can be reduced or avoided entirely through better understanding of humidity control issues, techniques and equipment," co-author Lewis Harriman said. "The potential benefits are large, because more than 50,000 commercial buildings are built every year in America alone."
Harriman said building owners in North America and Europe are beginning to pay more attention to humidity control. Numerous studies have illustrated the damage caused by humidity and moisture. One such study by the American Hotel and Lodging Association shows that more than $68 million is spent annually by association members to mitigate problems caused by mold and mildew.
"While the information in the guide was written primarily for the HVAC designer who 'has to get it done by Friday,' it helps all members of a building team who seek to keep costs to a minimum, avoid classic moisture-related problems and improve comfort for occupants," Harriman said.
Specific advice in the book includes:
- Installing a separate ventilation system to dry or humidify the incoming ventilation air.
- Calculating the moisture load separately from the sensible heat load.
- Sealing all ductwork, air handlers and duct connections tightly.
- Never oversizing the cooling equipment.
- Calibrating humidity sensors in-place (after installation and before commissioning).
The book includes sections on humidity effects, system design, equipment and controls, applications and design references. Guidance is provided for schools, office buildings, retail buildings, hotels, restaurants, museums, libraries and archives, hospitals, eldercare buildings, dormitories, swimming pools, ice rinks, dry air storage and laboratories.
The information was developed as part of ASHRAE Research Project 1047, funded by ASHRAE, the United States Department of Energy and the Gas Technology Institute.