Engineered Systems - November 2008 - (Page 32)

When it has to be stainless, it has to be A-J! The experts in stainless steel clean air systems The IAQ TOP 1O Negative air pressures can make buildings vulnerable to some types of problems. For instance, when a drain trap becomes dry, sewer gases infiltrate into the building if the building has a negative pressure, but do not if there is a positive pressure. So remember that “Sick Buildings Suck” and k i “Healthy Buildings Blow.” ” cal University of Denmark, once told me the ventilation “should be served like champagne, cool and dry.” Cooler air is just perceived by the brain as being fresher, and maintaining air temperatures at the cooler end of the acceptable thermal comfort range results in improvements of perceived IAQ. Thermal comfort complaints also comprise the largest source of trouble calls in office buildings. Providing occupants some individual control of the indoor air temperature also improves their perceived acceptability of the indoor air. AIR PRESSURE More important than outdoor air ventilation, which currently is the only IAQ aspect of the ventilation system performance that is regulated in building codes, is controlling the building space pressures. Generally, except in very cold climates, you want to have the building air pressures positive with respect to outdoors. Rather than “Sick Building Syndrome,” the term SBS more aptly means “Sick Buildings Suck.” When a building is operated with a negative air pressure, the result is that many unintended flow rates of air into the building develop, including infiltration of soil gas into the building and infiltration of unfiltered and unconditioned air into the building. In air conditioned buildings in hot humid climates, the infiltration of hot humid air into wall cavities can result in condensation and mold growth. Also, negative air pressures can make buildings vulnerable to some types of problems. For instance, when a drain trap becomes dry, sewer gases infiltrate into the building if the building has a negative pressure, but do not if there is a positive pressure. So remember that “Sick Buildings Suck” and “Healthy Buildings Blow.” It is also important to keep special use areas that have odors/air contaminants (e.g. bathrooms, janitor closets, garbage rooms, high volume printing/copying rooms) under a negative air pressure with respect to adjacent areas with air being exhausted directly outdoors. OUTDOOR AIR VENTILATION The supply of outdoor air to a building is essential to the creation of an acceptable indoor air environment. Ventilation is the only way to remove many indoor generated air contaminants from furnishings, equipment, occupants, and their activities. First of all, the system needs to be designed to bring in outdoor waste water treatment facilities, for plus: • Custom fabrication • Rush deliveries A-J Manufacturing offers a complete line of custom and standard stainless steel air distribution products, all designed and manufactured to offer durable, dependable and low maintenance performance necessary for waste water treatment facilities. What’s more, with our state-of-the-art manufacturing capabilities, we can also offer you the industry’s shortest lead times for custom orders. So for continuous linear, security grilles, modular diffusers and much more, contact A-J Manufacturing today! A-J Manufacturing 800-247-5746 • www.ajmfg.com Input 13 at www.esmagazine.com/instantproductinfo ES02084AJWasteWater.indd 1 12/13/07 2:37:23 PM 2 Input 49 at www.esmagazine.com/instantproductinfo 32 En gi neer ed S y stem s November 2008 3 http://www.ajmfg.com http://www.esmagazine.com/instantproductinfo http://www.shortridge.com http://www.esmagazine.com/instantproductinfo

Table of Contents Feed for the Digital Edition of Engineered Systems - November 2008

Engineered Systems - November 2008 Contents Editor’s Note HVAC Challenge Back2Basics Case In Point Commissioning Building Automation HVACR Designer Tips Show Me The Motor Money The IAQ Top 10 Putting A Damper on Tragedy Special: Lighting Controls Computers & Software Products Glossary Classifieds Advertiser Index Tomorrow’s Environment

Engineered Systems - November 2008

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