Influences of LED lighting on air-conditioning load and energy consumption in home-improvement center

In commercial buildings, installation of LED lighting has been accelerated due to their low electricity consumptions. Since the air-conditioning load caused by lighting is closely related to electricity consumptions of lamps, the air-conditioning load and energy consumptions of air conditioners should be also influenced if fluorescent lamps are replaced by LED. We examined quantitatively the influence of the replacement of lighting from fluorescent lamps to LED on the air-conditioning load and electricity consumption of a home-improvement center located in three regions in Japan. At first, we calculated the air-conditioning loads in the stores at every one hour through a year. Next, by combining those air-conditioning loads and the partial load performance of air conditioners installed in the store, we calculated electricity consumptions of the stores. By replacing fluorescent lamps with LED, the air-conditioning electricity consumption decreased by 32 - 56% in the cooling season whereas it increased by 32 - 75% in the heating season. Since the reduction of the lighting electricity consumption with LED was much larger than the change of the air-conditioning electricity consumption, the annual electricity consumption of the whole store decreased by about 40%.