Feeling comfortable in hot weather requires two things to happen together. The temperature and the relative humidity (RH) of the air must both be low enough to keep you from sweating. The lower the RH, the higher the temperature can be for you to feel comfortable. Think about dry heat in places, like Arizona, where 80 degrees can feel pretty comfortable, while that same temperature in Florida can be oppressive. That’s because the RH in Arizona is probably about 20% while in Florida it’s more like 90%. Lower the RH and you feel cooler right away.
There are two types of A/C: traditional, which removes moisture from the air, and evaporative cooling, used only in dry climates, which adds moisture while cooling. For the sake of this post, I’m only going to consider traditional A/C in humid climates, so if you live somewhere really dry, you can go enjoy planting your xeriscape garden (sniff) and leave us Southerners to discuss how to reduce the costs and environmental impacts of air conditioning in Orlando, Atlanta and other sweaty locales.
List and captions courtesy of Networx