18 May 2017

O.1.2.5 Influence of LED Lamps on Air-conditioning Load and Energy Consumption in Commercial Buildings

In commercial buildings, installation of LED lamps has been accelerated due to their low electricity consumptions.
The air-conditioning load caused by lighting is closely related to electricity consumptions of lamps. Therefore, if
fluorescent lamps are replaced by LED lamps, the air-conditioning load and resulting energy consumptions of air
conditioners should be influenced. In this study, we calculated the air-conditioning load in an electronics retail store
located in central Japan at every one hour through a year based on thermal characteristics of fluorescent and LED
lamps. Then, by combining those air-conditioning loads of the store and the partial load performance of air
conditioners, we calculated electricity consumptions of the air conditioners at every one hour through a year. By
replacing the fluorescent lamps with LED, the annual cooling load decreased by 17% while the annual heating load
increased by 30%, consequently the annual thermal load did not change so much with this lamp replacement. As a
result, the annual cooling electricity consumption of air conditioners decreased by 7 – 11% whereas the annual
heating electricity consumption increased by 9 – 20%. However, because the reduction of lighting electricity
consumption with LED lamps was larger than the increase of the annual heating electricity consumption, the annual
electricity consumed by lighting and air conditioning decreased by 21%.