Recessed light fixtures: infiltration energy loss

A study showed that fluorescent bulbs can reduce convective energy losses by 15-65% as compared to incandescent bulbs. To understand the heat loss that occurs due to the infiltration around the recessed light fixtures of a classroom, the infiltration was measured experimentally. Measurements were taken for three incandescent bulbs (50, 75 and 100 W) and one fluorescent bulb (13 W), with pressure differences between the room and the attic ranging from 0-3 Pa. Results showed that in general, losses increased with the bulb power rating and pressure difference. The infiltration rates measured were approximately 5 L/s, for a pressure difference of 3 Pa. This appears higher than the 0.9 L/s set by the Washington State Energy Code at a pressure difference of 75 Pa. The infiltration that occurred around the recessed light fixture caused considerable heat loss from the room to the attic. The 13 W fluorescent bulb resulted in a smaller heat loss and much lower operating costs than the incandescent bulbs, though it requires a longer fixture to provide illumination. For recessed light fixtures adapted to suit its extra length, the fluorescent light bulb would be an energy saving option.