Govt. offices have large spaces of occupancy out of which only a few spaces are air-conditioned. Given the high movement of people in an office, it is not feasible to go with conventional HVAC systems for these kinds of spaces. Cost constraints add up to the causes. In spaces where air conditioning is not possible, comfort to the occupants needs to be given.
Structure cooling with a two-stage cooling tower is a solution for these kinds of spaces where the structure of the building is cooled.
By using structure cooling with the two-stage cooling tower:
1. We are reducing the heat load of the space by cooling the structure of the building- the largest source of indoor heat.
2. Comfort cooling can be achieved through a normal ceiling fan operation.
3. The power consumption of the cooling tower is only 0.05 kW/tonne while conventional system consumes around 1-1.2 kW/tonne.
4. Life of the system is more than 50 years as PERT pipes are used.
5. The maintenance of slab cooling systems is simple and cost-effective as minimal resources are used.
Structure Cooling is done during the construction of the building where PERT pipes are embedded in the ceiling of the building.
Figure 1 Structural Cooling
Chilled water at around 20-24 degree Celsius is circulated through the two-stage cooling tower. The two-stage cooling tower is capable of providing chilled water at the wet-bulb temperature of the ambient. This chilled water takes away the heat from the thermal mass of the building thereby reducing the heat load of the building.
Structure cooling takes away the heat present in the structure of the building reducing the re-radiated heat. Structure cooling can provide 40-45 W/sq.mt of area installed.
Structure cooling with the two-stage cooling tower is the way to go forward for low energy consumption comfort cooling, specially in places where conventional HVAC systems can’t be implemented such as Govt offices, primary health centres. By using structure cooling, we offset a significant amount of GHG emissions by consuming only 0.05 kW/tonne of cooling.