Consulting-Specifying Engineer - December 2007 - (Page 16) M/E Roundtable FISK: There are a couple dozen studies showing that air conditioning leads to respiratory and non-respiratory symptoms among office workers. We don’t know why, but if you examine the evidence, more than likely it’s microbial. Air-conditioning systems become contaminated with microbes such as bacteria and fungi, which may be inhaled by building occupants. One preventive measure is to keep air conditioning free of contamination by an HVAC system design that eliminates wetting of duct surfaces by water condenses on cooling coils. Maintenance also is key. Building staff must make sure drain pans actually drain. We speculate that UV radiation of cooling coils, which is effective in reducing mold and bacteria growth, will reduce respiratory symptoms, as was shown in one study. STREIFEL: Maintain these systems. Fan coils get full of all kinds of biological material; it becomes aerosolized and do it all alone. The problem also resides in building enclosure, floor coverings, furnishings, finishes, and other sources as well. Pre-design needs a bigger budget allotment so that engineers and building staff can meet in the pre-construction phase and interact with the architect. transported throughout the building in a very short time. When it dries, it flies. Looking at the infectious disease process in hospitals, there is a short period time when microorganisms are actually in the environment. The tolerance level is not there, but the sensitivity is, among patients with open wounds or otherwise immunosuppressed. BRENNAN: Some changes that can be made to HVAC systems are keeping the place dry, clean and pest free. However, mechanical systems and personnel cannot CSE : Do you think that HVAC systems’ design budgets will increase due to the updated guidelines? If so, which specific area of the predesign of HVAC systems would need a larger budget allotment? BRENNAN: More than likely, HVAC system design costs are not going to be allowed to go up. The only way around that is to develop a good building enclosure system. STREIFEL: The problem with most HVAC systems is that they are not maintainable. They put them in such tight places that you cannot get in to do the proper filter changes, and they do not put the drains in right. There needs to be an emphasis on proper construction of the air handling system. BRENNAN: The most specific area of the pre-design that needs a bigger budget allotment would be the opportunity for engineers and building guys to meet pre-construction and interact with the architect. When the architect is involved, the facility personnel need to be there to ask specific ‘what if’ questions. Currently, there usually is no budget allotment for annual simulations that need to be done. CSE: In an office building HVAC system, what specific allergens affect employees’ respiratory systems and which allergen is the most harmful? What source controls would you recommend? STREIFEL: Mold spores affect employees. Moisture management controls, recognition of water stains and damage, (Continued on page 20) And you thought Swiss watches were impressive. Jaeggi. It’s pronounced “Yay-gee.” It means Swiss-engineered cooling towers that embody unprecedented quality, reliability and water and energy efficiency. Available for the first time in the United States, this innovative, patented Hybrid Dry Cooling Tower technology will debut at the AHR Expo in New York. Visit our booth or website to learn how environmentally conscious companies are benefiting from significantly reduced operating costs and up to 80% water savings by using Jaeggi Hybridcoolers. You’ll be impressed. AHR EXPO New York January 22-24, 2008 Jaeggi Booth #8549 Jaeggi. Changing the language of industrial cooling. 760 541-9308 www.jaeggi.us Input #211 at csemag.com/quickResponse 16 Consulting-Specifying Engineer • DECEMBER 2007 http://www.jaeggi.us http://www.jaeggi.us http://csemag.com/quickResponse
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