I am working on a project to consider how much air conditioning in a metropolitan area raises the temperature outside. I am trying to figure out how to translate the temperature outdoors (say 32 degrees C) into watts per square foot. Once I have the watts per square foot of heat already in the air, I plan to estimate the amount of heat dumped by an air-conditioner with a Coefficient of Performance of 3. Then I want to see how many watts per square foot are being dumped into the air by houses. So I will want to calculate the amount of temperature rise as a function of watts per square foot. Do I need to use the heat capacity of air? *EDIT How would I calculate the heat capacity of moist/humid air?