Human Body Temperature based Air Conditioning Control System

Abstract

Air Conditioners and air conditioning systems are integral part of almost every building and they contribute a significant part of the total energy consumption. In Nigeria, heating and cooling appliances accounts for about 44% of utility bills. With exponential increase in the use of cooling devices, there is a simultaneous increase in the electrical power consumption and occurrence of health issues, such as building related symptoms and sick building syndromes due to air conditioners. Hence, there is a need to fathom other ways of operating the air conditioning systems in other to minimize the energy consumption and other health related issues. In view of this, we have applied a Novel control method to regulate the operation of the air conditioning systems in offices and single rooms, based on the occupant’s or resident thermal comfort as against the traditional method based on the indoor temperature. The control signal is based on the occupant’s body temperature which is obtained via sensors on a table within the office or room. This information is sent to a microcontroller (AT89C52) where it is compared with a reference temperature and the air conditioner is regulated accordingly. The system was evaluated using the body temperature of many people either “with normal” or “above normal” thermal states. The result of the evaluation shows that the system’s response is faster in temperature regulation when used for subjects with body temperature “above normal” thermal state. Furthermore, the operational time of the new method is significantly less than that of the old (traditional) method which definitely accounts for the reduction in the total energy consumption.