District Cooling: A profitable and energy-efficient solution for climate emergency
As climate change warms the world, we increasingly need to find ways to efficiently cool our buildings – whilst also lowering our emissions to attempt to halt the temperature rise as much as possible. Traditional air conditioners are a poor method of achieving either goal, but what if there was another way?
District Cooling System
District Cooling System is the structured way to air condition clusters of buildings and offices simultaneously. A District Cooling System (“DCS”) produces chilled water within a centralized energy plant and distributes it through underground pipes to buildings connected to the system and provides them with air-conditioning. Therefore, individual buildings do not need split systems, chillers and/or cooling towers.
A DCS consists of three primary components: the centralized energy plant, the distribution network, and the Energy Transfer Station (“ETS”), which comprises heat exchangers between the primary (DCS side) and secondary networks (Building side)
Why are conventional cooling systems failing?
- Oversizing of Equipment: Building level cooling units will be designed for peak load + reserve
- Energy Wastage: Majority of the units works at part load and will be designed for peak load which leads to energy wastage.
- Most cooling users will not have expertise to ensure optimum operation of their cooling units
- Higher Green House gas Emission.
Benefits of DCS:
- Energy saving
- Reduce Green House Gas Emission
- Reduce Noise Pollution
- Reduce Refrigerant Usage
- Improve Building Space Utilization
- Reliability and Flexibility
Case Study
IIM Trichy
Project: IIM Trichy
Architect: CnT Architects, Bangalore
Sustainability and MEP Consultants: McD BERL
Typology: Institutional Campus which consists of Admin, Academic, Library, Hostel, Staff Quarters, Auditorium
Area: 175 acres, Total Built up area of 7 million Sqft
The purpose of this study is to present a techno-economic analysis of a district cooling system for an educational institute located in a hot and dry climate. The institute has a diverse cooling load pattern throughout the year, with a cumulative cooling load of approximately 800 TR. The district cooling system was designed according to a systematic approach, which was implemented in the project. Life cycle cost analysis is conducted for both individual air conditioning systems and district cooling systems. Based on the analysis of the case study, the plant capacity is reduced by 60% by using district cooling system.
A total of 7 buildings on campus are supplied chilled water by DCS, which operate at different HVAC loads. The plant room’s total cooling load is around 800TR. In the daytime, the chiller serves all Academic, Administration, Library, MDP buildings, and at night, Hostels, Residential buildings, and IT buildings.
There is only one proposed plant room for this project. For each of these buildings to have its own air-conditioning system, it would have required individual systems for more than 1750 TR and taken more than 2100 kW power connection as opposed to the current DCS power demand of 990 KW. During peak demand, the chillers in the plant room are sized based on day load.
Comparison between BAU and District cooling system savings
Conclusion:
- DCS offers several benefits which will vary dependent on the technology chosen to produce the chilled water.
- District cooling can lead the way to reduce environmental impact from cooling of buildings through its
- Source independent nature
- High energy efficiency – large scale advantages
- Utilization of simultaneity in the cooling demand
- District cooling can act as a load shifting technology for the electrical grid (Electrical grids get more fluctuating in the future)
