Book highlights common problems seen in hot and humid climates, along with practical alternatives for avoiding such problems.
By Traci Purdum
In October 2006 ASHRAE was confronted with questions regarding hot and humid climates. Specifically, the questions asked: What should owners, architects, hvacr designers, contractors and building operators be thinking about when they build air-conditioned buildings – in a sustainable way – in hot and humid climates?
Also, could the international organization aimed at promoting a sustainable worldprovide simple and practical suggestions to help busy, overworked professionals make better decisions?
The answers are presented in “The ASHRAE Guide for Buildings in Hot and Humid Climates,” (2008, American Society of Heating, Refrigerating and Air-Conditioning Engineers).
Topics covered in the book include improving thermal comfort, managing ventilation air, reducing energy consumption and avoiding bugs, mold and rot. The book explains ASHRAE’s standards in these areas. It also highlights common problems seen in hot and humid climates, along with practical alternatives for avoiding such problems.
“All countries want to achieve high standards of energy efficiency,” notes author Lewis G. Harriman, AHSRAE member and director of research and consulting at Mason-Grant, a technical research and training firm based in Portsmouth, N.H. “But recent history warns that mold and mildew problems in hot and humid climates can overshadow any gains made through energy reduction. On the other hand, the practical experience of ASHRAE’s members shows that by focusing on several critical building enclosure design details and by keeping the indoor air dry, owners and designers can avoid mold problems and have high indoor air quality, while their buildings use much less energy than outdated designs."
The 123-page book is peppered with several topical photos, charts and illustrations aimed at helping readers define the basic layout and general requirements of a building, its systems and the levels of effort needed for operation and maintenance.
For example, Chapter 5 – Avoiding Bugs, Mold & Rot – suggests readers use mastic to seal duct connections to save energy and reduce mold risk. Noting the solution is “not pretty,” it is the most effective way to eliminate a well-known risk factor for mold.
This chapter also notes that every condensate pan needs a trapped condensate drain line. Otherwise, water will stay in the pan and grow bacteria. The trap must be deep enough to resist the air pressures and suction generated by the fan.
