Human comfort in an interior space is something that many may take for granted. That comfort is partially due to our ability to manipulate and control the environment in that space. Heating, ventilating, and air conditioning (HVAC) is the tool that allows us that control. There are many factors that go into the design of HVAC. Some of those variables are determined from the conditions of the space and the environmental conditions. Examples include the size of the space, the layout of radiant heat sources in that space, and the number of occupants in that space.