422 Energy Project Financing: Resources and Strategies for Success
for determining emission rates, and because of the health effects
resulting from exposures to many VOCs and VOC mixtures are
poorly understood. Many cleaning, painting, and pest control
activities should be performed when the building is unoccupied.
Cleaning and pest control products must be properly diluted and
applied.3 To limit indoor growth of fungi and bacteria, water leaks from
plumbing and the building envelope should be eliminated. Build-
ing materials that become wet should be dried rapidly (e.g.,
within 1-2 days) or removed and replaced Construction materials,
including concrete, should be dry before they are covered (e.g.,
with carpet) or enclosed (e.g., in a wall cavity).
4 To limit microbiological sources in HVAC systems, sources of
moisture in HVAC systems must be controlled. The entry of wa-
ter droplets and snow into outside air inlets must be restricted
by proper design of the air intake system, e.g., use of rain-proof
louvers and limiting of intake air velocities. Condensate drain
pans must drain fully, be cleaned periodically, and have proper
traps in the condensate drainage systems. Air velocities through
cooling coils and humidifiers must be restricted to prevent wa-
ter droplets from being entrained in the airstream and wetting
downstream surfaces.
5 To limit microbiological sources in buildings, condensation of
water vapor inside the building envelope and on interior build-
ing surfaces, including slab floors in contact with the soil, must
be limited by controlling indoor humidity, proper use of mois-
ture barriers and thermal insulation in the building envelope,
and through control of indoor-to-outdoor pressure differences.
Specific requirements will vary with climate.
6 A building should not be constructed on soil with unusual levels
of hazardous contaminants (VOCs or radon) or special measures
should be used to prevent soil gas from being drawn into the
building. When building slabs are constructed on soils that are
unusually wet, water proofing should be used to limit moisture
transport from the soil into the slab.