A design of fuzzy controller for conforming to the regulations of indoor air quality and thermal comfort

Most of the time people stay in the indoor environment, so Taiwan government established indoor air quality (IAQ) regulations to protect public health and the living environment. This study defined fuzzy sets and fuzzy rules according to the national IAQ and standard ANSI/ASHRAE 55-1992. The fuzzy controller determine the operation time of air conditioner and exhaust fan to meet the national IAQ regulations and accepted thermal comfort. Using relay to switch the power of AC exhaust fan ON during operation time computed by fuzzy controller is cheaper and simpler than using variable frequency technology to control the wind velocity of AC exhaust fan. The study used exhaust fan to draw the outside cool and dried air into inside to help air conditioner to meet the standard thermal comfort quickly, so the air conditioner can decrease the operation time to save power.