Air Conditioning and Water Heating-An Environmental Friendly and Cost Effective Way of Waste Heat Recovery

Rahman, M. M. and Chin , Wai Meng and Ng, Adrian (2007) Air Conditioning and Water Heating-An Environmental Friendly and Cost Effective Way of Waste Heat Recovery. AEESEAP Journal of Engineering Education, 31 (2). pp. 38-46.

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Nowadays, besides the air conditioning unit, another comfort providing equipment that can be found in many homes in Malaysia is the instant water heater system which is often used in the morning when both the weather and water temperature are low. However, the instant water heater consumes a considerable amount of electricity and users have to pay for it. There is still a possibility to obtain hot water without using any extra electric power if the air conditioning and water heating systems are integrated. Therefore, this paper presents the research on the establishment of waste heat recovery device from split air conditioning system. So far, two types of research activities have been conducted to recover waste heat from split type air conditioning systems. For the first type of research the condenser of the air conditioning unit is replaced by the copper tube, which is submerged in a water tank to warm up the water to be used for domestic purposes. The results showed that the temperature of the water in the heating tank can be raised from 25ºC to 42ºC and at the same time, the temperature of the evaporator can be lowered down from 27ºC to 18ºC within 7 minutes. In order to avoid the possible contamination of water with the refrigerant, which may be harmful for human health, the second type of waste heat recovery device from split air conditioning was initiated. In this case, the heating tank is designed in a way that the copper tube conveying refrigerant is not submerged in water. The heating tank consists of two cylindrical chambers, the inner chamber, which is filled with water, is coiled with the hot refrigerant conveying tube at the outer surface. The annulus of inner chamber and outer chamber is filled with insulating materials to avoid heat loss. This device may increase the water temperature from 30ºC to 75ºC within 8 hours of operation. By using these type of heat recovery devices, compressor efficiency can be improved and at the same time, warm water for domestic purposes can continuously be obtained free of charge. The end result is faster cooling and prolonged compressor life. This system is simple and not costly and able to save the water heating cost and at the same time, safe in environmental aspects, i.e., less heat is rejected to the environment.

Item Type: Article
Uncontrolled Keywords: Waste heat recovery, air conditioning, warm water, and environmental friendly.
Subjects: T Technology > TD Environmental technology. Sanitary engineering
Date Deposited: 31 Jul 2013 03:01
Last Modified: 31 Jul 2013 03:01

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