The concept of district heating refers to a group of customers, or even a whole city, which shares a system providing ambient heat, often using steam or water heated by sources that emit less carbon dioxide. A network of insulated pipes, constructed underground in a community, transports the heat among customers, and various meters and billing systems keep up with how much heat is provided.
District heating
District heating is seen as an increasingly important option, as municipalities seek to lower their carbon footprints to ‘net zero’. In addition to producing less pollution than individual alternatives, district heating systems also have competitive pricing.
The option is especially attractive in areas that are more densely populated and where new blocks of housing or businesses are being constructed. In the United Kingdom, district heating can help to achieve new Sustainable Development Goals.
Leverage central supply of hot water
A district heating system might leverage a central supply of hot water, transported through a network of pipes
A district heating system might leverage a central supply of hot water, transported through a network of pipes, located underground in a community. Heat sources might include waste from forests, such as branches or wood timber, waste timber from building sites, or even surplus heat from industry or data centers. Heat waste from industries can be reprocessed and reused.
In recent decades, renewable heat from geothermal wells, solar collectors and biomass fuels have also been introduced. High taxation of natural gas in some jurisdictions provides an incentive to seek out alternatives, such as district heating.
District cooling
District cooling has also been deployed in some areas. The first district cooling system was introduced in Sweden in 1992. The United States leads the world in district cooling (chilled water networks).
Although an emerging option in many areas, district heating has been popular for years in Scandinavia. In Sweden, for example, district heating was introduced in 1948 and more than 50% of the country’s commercial and residential buildings are served by district heating. The technology dominates the business-to-business segment in Sweden, with more than 90% of the market share for multi-dwelling buildings and around 80% for non-residential buildings.
Space and cost savings
District heating is also used in single-family residential houses, industrial premises, and ground heating for snow removal. District heating allows customers to save space and expenses, by avoiding individual installation, operation, and maintenance of in‐building heating, cooling, and water‐heating equipment.
Using economies of scale, district systems often distribute heat generated by combined heat and power (CHP) systems, to use thermal energy that is produced more efficiently. Renewable and lower-carbon energy resources include biomass, geothermal, surplus industrial heat, solar energy, or cold lake or ocean water that may not be feasible on an individual-building basis.
District systems in commercial buildings
District systems are more commonly found in commercial clusters of buildings
District systems are more commonly found in commercial clusters of buildings, such as colleges, hospitals, downtowns, healthcare, and government campuses. In the United States, common applications for district heating and cooling systems include colleges/universities, central business districts, residential and mixed-use clusters, military bases, healthcare campuses, schools and prisons.
By aggregating the thermal loads of dozens, hundreds, or even thousands of buildings, district energy systems facilitate investment in lower-carbon resources, and enable enhanced economic resiliency.
Communication and transparency
Communication and transparency, among inhabitants, heating providers, energy suppliers and property owners, are important factors in an effective district heating system. Centrally distributed heat will become more common as the industry works toward net zero goals, but factors, such as customer service and satisfaction will also need to be addressed.
