Energy Efficient Air Conditioning System Using Geothermal Cooling-Solar Heating in Gujarat, India
It is well known that one unit of electrical energy saved is equal to more than two units produced. One way of economizing the power is utilization of energy efficient systems at all locations. In the present study, the air conditioning system is analysed and an innovative way is suggested. We use natural low temperature of shallow sub surface (1 - 3 m) of the earth—geothermal cooling system. It is known that majority of the households and the apartment complexes in India have two tanks for water storage. One is the underground water sump and the other is the overhead water tank. In our study, we use these two water storage systems for space cooling during summer and also for heating during winter. The main aim of our paper is air-conditioning of the space in an economic way to save electricity. It is based on a simple idea of transferring the low temperature from underground water sump to the room in the house using water as a mode of transport. Since India is a tropical country located at low latitude, most of the year, the air temperature is high and demands space cooling. However, for a couple of months during severe winter months (Dec.-Jan.) at Ahmedabad, heating of the space is required. For heating the space, we suggest to use the well-known solar water heater. Effective use of heat exchanger is shown through computation, modelling schemes and lab experiment. We recommend geothermal cooling for 10 months in a year and solar hot water system during 2 months of winter. It is observed that the ambient air temperature of 35°C - 40°C in the room can be brought down to 26°C without much consumption of electricity. In a similar manner, the room temperature at night (13°C) during winter in Ahmedabad can be increased to 27°C through circulation of water from solar water heater in the heat exchanger.
Comparative study of silicon dioxide and kaolinite ratio for temperature and humidity variations of earth energy enabled cooling system and traditional cooler
Abstract The earth energy enabled (EEE) cooling system is designed in order to utilise the heat capacity of the earth effectively. For buildings, the EEE cooling systems are an effective passive heating and cooling medium. All countries opt for different types of solutions in order to decrease the consumption of residential building energy. In light of this, a new device called earth-air heat exchanger is under the development stage for achieving the increased efficiency and hence the improvement in economic competitiveness. This paper presents the comparative studies of silicon dioxide and kaolinite ratio for temperature and humidity variations of EEE cooling system and traditional cooler with some modifications in order to explore some new aspects by using water in place of air and the basic cooling principle of a simple cooler or cooling tower for cooling in summer season. A comparison of cooling effect produced by the traditional cooler and the EEE cooling system for different conditions has also been made. Results show that proposed EEE cooling system is much more efficient than the traditional cooler. It is shown that the EEE cooling systems are realistic approach towards energy consumption. They are the future of heating–cooling technologies.
Simulation of greenhouse microclimate produced by earth tube heat exchangers
Abstract The conditioning system studied in this paper consists of underground pipes laid horizontally which act as “air-ground” heat exchangers. Ambient air inside the greenhouse is forced through the pipes and subsequently expelled once more into the former. The system exploits the thermal inertia of the soil whose temperature at a certain depth is virtually constant. Two models simulating respectively the greenhouse and the underground pipes were modified and integrated so as to simulate the operation of the system. The heat and mass balance equations that constitute the resulting model are given. With the aim of finding the optimal characteristics of the system from the technico-economic point of view, this model was used to compute the heating of a typical greenhouse in the region (Humid Pampa zone, Argentina). The results obtained for different temperature requirements are given, together with the temperature gradients of the air inside the greenhouse on a typical day in winter, both with and without the conditioning system. Finally a comparison was made between the cost of running the system and a conventional one.