Description

Thermal comfort is achieved when a person can get rid of their metabolic heat with the least amount of discomfort. This heat loss occurs in three ways: radiation, convection, and perspiration.

When the surrounding structure is much cooler than the body, heat is mainly absorbed by radiation and convection. As the structure warms up, the loss by radiation and convection decreases, and the shortfall is taken up by perspiration. However, if the structure is either equal to or warmer than the body temperature, then the only means of heat transfer is perspiration, which is the primary source for thermal discomfort.

This welling of discomfort normally leads people to adopt artificial cooling devices such as air conditioners. However, air conditioning being an energy-hungry piece of technology is now becoming less and less sustainable. As a suitable alternative, the direct cooling of a structure allows the heat flow to occur mainly through radiation and convection.

There are many methods for cooling a structure that involve refrigeration and energy utilisation. However, we have studied the techniques used by our heritage buildings, which remain cool without using energy or any artificial cooling.

Our Zero-Impact System

The zero-impact system, which is based on these heritage buildings, consists of loops of plastic pipes that are laid directly on a surface and covered with screed. The pipes terminate in a small insulted tank, which also houses a small pump.

The pump slowly sends water through the pipe loops, each being approximately 100 meters in length. The water collects the solar heat and becomes extremely hot by the end of its travel. Thereafter, it passes through a radiator, dumping all the heat back into the atmosphere. Due to this technique, only lukewarm water returns to the tank, which is then recirculated. At night, the same water is circulated through the radiator to dump the residual heat. Therefore, in the morning, the water temperature is restored to its original state.

Variations to this system are available to overcome certain situations, and they include: overhead tank for multiple floors, evaporative pads for dry climates, and refrigeration for precise cooling. This system is more energy efficient than the power-hungry radiant cooling systems that are offered by the other MNCs.

Features

• Temperature of the slab bottom is maintained at 30°C with significant power savings.
• Reduction in air conditioning load, up to a minimum of 25%.
• Comfort is enhanced due to the elimination of solar gain from the roof.
• Decrease in the HVAC CFM/sq. ft. due to reduced sensible load.
• If solar panels are used, the environmental impact and the operating costs are reduced to zero.