Heating and cooling public spaces for people to assemble for work, entertainment and home life has been a challenge for the human race since the beginning of time. District heating was developed in ancient Rome to deliver hot water or steam heat to its structures. In the nineteenth century, the technology was perfected in Europe to meet the heating needs of countries with varying weather climates. Today in cities all over the world, district energy systems provide heating and cooling to public spaces such as commercial buildings, condominiums, hotels, sports facilities, universities and government complexes.
District energy systems produce hot water, steam or chilled water at a central plant and then distribute the energy through underground pipes to buildings connected to the system. Individual buildings do not need boilers, chillers or cooling towers. Customers use the hot and chilled water to meet their space heating, water heating, processing and air-conditioning needs. Once used in customer buildings, the water is returned to the central plant to be reheated and rechilled and then recirculated through the closed-loop piping system.
As a result, individual buildings served by a district energy system don't need their own boilers or furnaces, chillers or air conditioners. The district energy system does that work for them, providing valuable benefits including:
- Improved energy efficiency
- Enhanced environmental protection
- Fuel flexibility
- Ease of operation and maintenance
- Comfort and convenience for customers
- Decreased life-cycle costs
- Decreased building capital costs
- Improved architectural design flexibility
DOE Distributed Energy Program
The International District Energy Association: www.districtenergy.org
Cogeneration and District Energy: Sustainable energy technologies for today...and tomorrow. (PDF)