A testing program was conducted to examine comfort conditions in the perimeter zones of office buildings with linear slot type supply air diffusers. Three different types of exterior wall and window construction were simulated. The effects of exterior wall construction, supply air loading, air deflection pattern, and supply air diffuser location on the room temperature gradient and Air Diffusion Performance Index were analyzed . The results are discussed and qualitative conclusions are formulated concerning the influence of each variable on the comfort conditions.