The paper discusses the problem of the reduction in Coefficient of Performance (COP) in a refrigerator due to the inadequate position or some flow obstacles such as shelves in a room. The propriety of the present numerical method has teen proved by experiments using the flow visualization technique. The COP are calculated from the temperature rise of the condenser whose temperature indicates the condensing temperature of refrigerant The temperature rise is predicted by the theory of the steady two-dimensional laminar natural convection. In a room size of $2m;{ imes};2m$ the COP are decreased by 0.3 when the gap between the wall and condenser are decreased from 10cm to 2cm. While the COP are decreased by 0.55 as the shelf length increases from 0 to 75cm.