SOLUTION TO THERMAL COMFORT USING FUZZY LOGIC

Two objectives of thermal comfort and energy saving are heating, ventilation and air conditioning (HVAC) systems. Thermal comfort cannot be attained by a controller, as it impacted by temperature, relative humidity, air velocity, environment radiation, activity level and cloth insulation. Hence, a fuzzy logic concept was used to measure the thermal comfort level, but this measure is based on the air temperature, the mean radiant temperature, the relative humidity, the air velocity, the activity level of occupants and their clothing insulation. Sensation index of the fuzzy logic is obtained as a result of linguistic rules that render human's comfort level because of the interaction of the environmental variables and the occupant's personal parameters. This concept is based on Fanger's ‘Predicted Mean Vote'_PMV.equation. However, the new fuzzy PMV calculation, which is the controller feedback, is dependent on iterative solution and is capable of adapting easily with regard to users' specific thermal sensation, making it an attractive index for HVAC systems' feedback control. Of the two fuzzy controllers are developed, one with temperature as its feedback and the other with the PMV index as its feedback. It has been demonstrated that the PMV feedback controller seems to have a better control of the thermal comfort and energy consumption compared to the system with temperature feedback.