Through computational fluid dynamics studies, this paper analyzes the effects of and interactions between interior surface emissivity, positioning of forced-air supply/return locations, and building "tight-ness" on space-conditioning power requirements in a simple model room. Each is shown to be important, but all are highly interdependent. In well-sealed rooms, layout is shown to be largely unimportant and extremely low-emissivity (epsilon = 0.1) a slight (2-5%) benefit. With high infiltration or external ventilation requirements, poor supply/return locations can increase power usage twofold, and extremely low emissivity produces a +/- 20% change in power-consumption depending on the room layout. (C) 2015 Elsevier Ltd. All rights reserved.