Reducing Cooling Needs
An overly hot working space is typically due to an abundance of lighting, an improperly air sealed or insulated building shell, or bare west facing windows. To reduce cooling needs, replace incandescent lighting with fluorescent lighting; properly air seal the building shell (which can provide savings in heating needs as well), and incorporate awnings where appropriate on west facing windows. If you're designing a new building with many southwest- or west-facing windows, consider windows with a Solar Heat Gain Coefficient (SHGC) of no more that .32.

More information on insulation & air sealing.


Air Conditioning
If you're installing a cooling system, make it as efficient as possible. Appropriate sizing (i.e. BTU/hour) is essential. Much of the comfort in air conditioning comes from dehumidification. An oversized system often doesn't run long enough to effectively dehumidify, so the air becomes cold and clammy.

If you're considering a central system, a knowledgeable contractor can calculate the peak cooling load and size the system and ductwork appropriately using Manual J (peak cooling load) and Manual D (sizing and ductwork) for the necessary calculations. When outdoor temperatures are cool enough, economizers can run outdoor air through the system. The cool mornings and nights of Vermont summers make economizers a good option for central air conditioning in this area.

Ductwork that runs in attics, basements or anywhere beyond conditioned spaces should be sealed and insulated effectively. Studies show that without such measures, 20-30% of heated or cooled air is lost.