From the outside the theory behind air distribution appears very simple. It is simply the introduction of cool or warm air into a space in an attempt to achieve a temperature range which is comfortable for the occupants. While appearing simple from the outside it is in fact a very complex area which must take into consideration such factors as noise level, drafts and energy efficiency. The pages in this section attempt to cover some of these factors which must be accounted for in order to achieve a successful air distribution system.