Better dehumidification for commercial buildings.

States that to control humidity it is necessary to remove moisture load from ventilation air. The combination of increased ventilation and air conditioning brings more humidity in from outdoors with a greater chance that condensation will occur on surfaces chilled by the cooling system. Suggests that rooftop equipment for cooling is frequently oversized. Considers the nature and dimensions of the moisture loads. Gives tips for better dehumidification: first, be sure to estimate the peak moisture load separately from the peak sensible load; second, pre-dry the ventilation air before it enters the HVAC system; thirdly, seal up all return and exhaust ductwork tightly, and do not allow building cavities to be used as return-air plenums in place of sealed return-air ductwork; finally, resist the temptation to oversize the cooling equipment, since the longer the equipment runs to remove the sensible heat load, the more moisture it will remove.