Full Proposal in pdf - M E Rinker Sr School of Building Construction ...

• Improved ventilation: Including increases in the quantity of outdoor air(OA) supplied to a building, and/or improvement in the distribution andmixing of the supply air throughout the various zones in the building.• Air cleaning: Typically involving devices mounted in the central HVACducting, or self-contained devices mounted in the occupied zones, capableof removing particulate or gaseous contaminants from the circulating air.• Source management: This can include removal of all or part of the source,replacement of the source by a lower-emitting alternative, treatment of thesource to reduce emissions, re-location of the source, re-scheduling of thetiming when the source is allowed to be active, or re-location of thebuilding occupants in order to reduce occupant exposure.According to a survey that NIOSH conducted in 1987, 52 out of a 100 buildings withIAQ problems suffered from mainly inadequate ventilation. According to the samesurvey, 16% of the buildings suffered from indoor contaminants where 10% sufferedfrom outdoor contaminants (Seitz, 1989) The numbers clearly indicate that many IAQproblems derive from the building itself and its indoor air management systems.Manufacturers have been working on generating more advanced products for betterventilation technology. Another important issue in controlling the IAQ in a commercialbuilding is to be able to monitor IAQ constantly. Monitoring C02 levels is important sincestudies show that at levels beyond 1,000 ppm occupants can experience drowsiness andgeneral discomfort, making it more difficult for them to think and work (Bas, 1993). Thehealth effects of IAQ problems will be discussed in the IAQ and Health section in moredetail.Most commercial buildings use variable air volume (VAV) system for ventilation.However the main reasons VAV’s are used in commercial buildings derive from financialproblems. In 1970’s before the energy crisis, a different system that had a dual ductmixingbox with constant air volume but variable temperatures was popular in buildings.This system brought huge amounts of outside air into the building, however while theenergy efficiency became a more important concept, this system started to be less populardue to its expensive operating costs. The VAV system brings in only the amount of airthat is necessary and re-circulates much of a building’s already heated or cooled air.Although VAV system saves energy, re-circulating air and increased amount of aircontaminants is the price that is paid for those savings.Air filtration is another IAQ control technique. Many buildings use poor performancefilters usually with 89 % performance filters, which are used to protect the HVAC systembut not the occupants of the buildings. According to ASHRAE the performance of thesefilters on filtering dust and similar contaminants is only 7 to 12 % effective.