Engineered Systems - November 2008 - (Page 36)

The IAQ TOP 1O the building is built so this becomes an important design decision. Apparently, many architects have difficulty with the visual aesthetics of the outdoor air intake and put it in the rear of the building with the loading dock and garbage dumpsters. Having the outdoor air intake located on the roof of the building also is more secure than one at ground level. duration will depend upon the specific sources in the building and can be determined on a trial basis using building odor as a criteria. When construction and tenant improvements are being performed in an occupied building, it is very important to isolate the work area from the occupied area, including shared ventilation systems. The days of simply posting a sign “Pardon the Dust” are long gone. 5 INDOOR SOURCE CONTROL Make sure to use low-emitting materials and finishes, and cleaning products. Avoid using products with urea-formaldehyde resins such as composite wood products like medium-density fiberboard and particleboard. These products can emit significant amounts of formaldehyde gas into the indoor air for many years after installation. Formaldehyde is both a known human carcinogen and a potent eye and respiratory system irritant. There are composite wood products available that use alternative resins that do not emit formaldehyde. The Collaborative for High Performance Schools (CHPS) has a list of products on its webpage (www.chps.net/lem_table.htm) that meet the strict material contaminant emissions criteria of California’s Architectural Specification 01350. Use these products wherever possible and following painting and carpet installation, configure the ventilation system to provide 24/7 ventilation with the maximum percentage of outdoor air that is possible to flush away fumes. Typically, flushing the building continuously for a few days to two weeks results in a satisfactory reduction of indoor emissions. The exact 6 MOISTURE CONTROL Controlling moisture in a building so that it does not accumulate is essential to preventing mold from growing, disseminating mold spores into the indoor air, and degrading the IAQ. As described in the “A California Builders’ Guide to Reducing Mold Risk” (http://iee-sf. com/workshops-seminars/pdf/BuildersMoldGuide.pdf) the three strategies for reducing mold risk are: 1) Keep the water away with proper site drainage. 2) Keep the water out with proper window/door flashing, foundation waterproofing, vapor retarder placement, and wall drainage system. 3) Limit mold growth while moisture dries out with selection of moisture-tolerant materials. Probably the most moisture intolerant material in a building is paper-faced gypsum wallboard (drywall, sheetrock). The paper on gypsum wallboard is glued to the gypsum using a starch-based adhesive, which quickly grows mold when it becomes wet. Input 183 at www.esmagazine.com/instantproductinfo ESM09084Emon.indd 1 ed S y stem s 36 En gi neer November 2008 8/19/08 3:30:09 PM http://iee-sf.com/workshops-seminars/pdf/BuildersMoldGuide.pdf http://iee-sf.com/workshops-seminars/pdf/BuildersMoldGuide.pdf http://www.chps.net/lem_table.htm http://www.emon.com/es9.asp http://www.emon.com/es9.asp 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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