Direct structure cooling

Direct structure cooling is a method of removing heat from the floor by laying a coil of plastic pipe between the slab screed and the tiling. The pipe is completely encased in the bedding. Water circulated in the pipes is cooled by a central chiller through a heat exchanger. Main Advantages 1. It removes solar load that travels through the structure and thus reduces the cooling load on the air system. This results in smaller air flows and thinner ducts, permitting higher ceilings. 2. Cooler floor and ceiling reduce the Mean Radiant Temperature, enhancing the feeling of comfort for the same temperature and humidity 3. The heat is removed at a higher temperature (about 25 DEG.C) rather than 2 DEG. by the chiller. Since the condensing temperature is the same, the power consumption is lower. Proposal Each flat will have grids of piping, of certain fixed length, embedded beneath the floor in the balcony (since maximum sunlight is incident in the balcony area) as shown in the policy drawing. The grids are connected to common supply and return headers. Water under vacuum is circulated in these grids. The reason for circulating water under vacuum is as follows- Water boils at 100 °C at atmospheric pressure. It requires around 2300kJ/kg of energy to change its state from liquid to vapor. During the process of change of state there is no change in temperature of water. This is of significant importance since large amount of heat is being absorbed without any rise in temperature. Now when the same water is under vacuum say 0.5 PSI or 0.03bar, it boils at 27 °C. Therefore by circulating water under vacuum large structural heat loads can be easily tackled without the use of any air conditioning. The vapor is then condensed back to liquid by rejecting heat to chilled water in a plate type heat exchanger. The heat exchanger is kept in the drying yard/servant’s room. Chilled water is produced in chillers which will be installed at the service floor. These water chillers operate on high temperature refrigeration and hence work more efficiently. Each service floor will have separate chiller for each wing, hence there will be four chillers on each service floor. These four chillers will cater to the pipe grids which are installed on the floors beneath it and above the next service floor (counting from top to down). Treated Fresh Air System is a simple but effective way of maintaining high IAQ within the conditioned space with simultaneous savings in energy cost. The Conventional Process The conventional method involves mixing the room return air with fresh air from outside, and treating this mixture in the cooling equipment. However this process wastes energy since all the supply air is treated to low temperature refrigeration which is not required. This is so because low temperature refrigeration is primarily intended for dehumidification and in practice only a small amount of dehumidified air is required to meet the moisture (latent) load & the fresh air requirements in the conditioned space. The remaining air can be treated to relatively high temperature refrigeration. But since a conventional system treats all the air to low temperature refrigeration it wastes energy. Moreover all the air is then supplied at a remote corner in the conditioned space which does not contribute significantly to the IAQ. Treated Fresh Air System This systems aims at eliminating the drawbacks of a conventional system by using the following technique 1. Fresh air from outside is not mixed with the return air from room but 2. Unlike the conventional system only this small amount of air (typically 15-20% of total supply air) is treated to low temperature refrigeration in the cooling equipment and the remaining air is subjected to high temperature refrigeration. This process can save up to 20-30% of total energy spent on cooling. 3. Rather than supplying air at remote corners in the conditioned space this treated fresh air is supplied directly in areas (through jet nozzles) where the probability of human occupancy is more e.g. near the dining table, above the bed etc. This maintains high IAQ in these areas. PARTIAL LIST OF, ENERGY CONSERVING APPLICATION PROJECTS
NATURAL COOLING SYSTEMS
Orange Life - Residential cum commercial THREE TIER/ TWO TIER COOLING SYSTEMS
Thacker industrial estate, Mumbai –Own Office

Source: http://www.panasiaengineers.com/pdf/Palais_Royal.pdf