Radiant Cooling Solution for Building Sector by Oorja Energy Engineering

 

With rapidly increasing urbanisation and sprawling cities, building sector has become a significant contributor to the global energy consumption and associated carbon emissions. According to the Fifth Assessment Report (AR5) of the United Nations Intergovernmental Panel on Climate Change (IPCC), buildings accounted for 32 per cent of total global final energy use and 19 per cent of energy-related greenhouse gas (GHG) emissions in 2010. Additionally, GHG emissions from the building sector have more than doubled since 1970 to reach 9.18 GtCO2eq in 2010.

 

Most commercial buildings have a centralised Heating, Ventilation and Air Conditioning (HVAC) system to meet the indoor cooling demand. Enhancing efficiency in these systems mostly focuses on chillers by making the compressors more efficient. Also, the cooling distribution in these systems is a significant contributor to energy consumption in commercial buildings and uses air as a heat transfer medium. The distribution of cooling, however, still remains a neglected area in the HVAC systems.

 

Oorja Energy’s “Radiant Cooling Solution” addresses this area by focusing on increasing efficiencies in cooling distribution. This solution turns surfaces in the room like the floor or ceiling into heat sinks that absorb the sensible heat in the room. These surfaces like the floors, ceiling or even false ceiling are turned into heat sinks by embedding pipes in them, instead of blowing the air over a heat exchanger as is done in an Air Handling Unit (AHU) in the conventional system.

 

Being at a lower temperature than the heat sources, these surfaces embedded with pipes having cold water circulation absorb the heat radiated from occupants, lighting, equipment, walls, glazings, furnitures, etc. The heat is finally transmitted to the water flowing in these pipes. The heat thus taken away is rejected using a chiller. In addition to floor cooling, Oorja also offers radiant cooling solutions for walls and ceilings by placing the heat exchange panels in the room itself.

 

Oorja’s radiant cooling system operates on chilled water supply between 16-20°C as compared to conventional centralised HVAC systems that require chilled water supply at 7°C. This leads to significant savings on the power as the compressor has to work more to produce chilled water at this low temperature. Furthermore, the solution does not require high powered motor to transport large volume of air through the ducts. Instead, it requires much smaller motor for pumping the water for the same output. As a result of these innovative features, radiant cooling solution offers a reduction of 30 per cent in energy consumption. Depending on the nature of the projects, radiant cooling solutions can payback the cost in less than three years.

 

In addition to lower energy consumption, the system comes with added benefits. It helps reduce noise levels and lower radiating heat from various objects makes the occupants feel comfortable even at higher room temperatures. Radiant cooling reduces the need for air re-circulation, thus, leading to improved indoor air quality.