A study of solar control film in a hotel building

Energy tariff is a major cost in hotel operation. Effective use of energy can reduce operational expenditures and has important environmental benefits. Solar heat gain particularly through fenestration, contributes to a significant proportion of the building envelope cooling load. More solar radiation means more total solar heat gain and hence, more cooling requirements and larger electricity consumption for air-conditioning in hot summer. Daylight makes an interior space look more lively and attractive and people expect good natural lighting in their living spaces. Daylight is always accompanied by solar heat gain. Due to the small angle of incidence, direct sunlight can be excessive for east-facing windows in early morning and west-facing windows in late afternoon. To avoid the problems of glare, excessive brightness and thermal discomfort, occupants may block the windows with internal shading devices, resulting in poor daylighting performance, switching on electric light fittings and completely isolating with the outdoor environment. Recent advances in thin film coatings for window glass products provide a means of substantially reducing heat gain without proportionally reducing daylight transmittance. It indicates that cooling energy can be reduced, while people can enjoy more natural light and maintain visual contact with the outside environment. This study presents the optical and energy performances of a solar control film coating installed in a guest room of a three-star hotel located in Hunan Province, China. The findings indicated that solar film coating can cut down cooling load without substantially reduce the indoor daylight illuminance level. Proper solar film coating designs would minimize the building energy expenditures and maintain the visual and thermal comforts.