History of District Heating

A District Heating project is where there is a single centralised heat source supplying heating water and / or domestic hot water two or more separate buildings on the site via an underground pipe network. At the heart of the district heating philosophy is the concept of improving energy efficiency, reducing CO2 and saving on running costs by having one large heat source running very efficiently, rather than each building having separate smaller ones running less efficiently. District heating projects range in scale from a heat source supplying 2 or 3 properties all the way up to city-wide schemes. This short article investigates the history of district heating in the UK and around the world.

District heating was first used on a wide-scale in Denmark. When the oil crisis hit in 1973 and the price of a barrel of oil quadrupled unfortunately this left Denmark in a very difficult situation (at the time over 90% of its energy came from imported oil). In the aftermath of this crisis Denmark changed energy policy and started investigating heavily in renewables and district heating – 40 years later 63% of its citizens are supplied by district heating networks and Denmark is actually a net exporter of oil. Heat networks are also now common in Scandinavia, Eastern Europe, Germany, South Korea and major cities in the USA and Canada. There are also increasing in the growth regions of China. District heating still only makes up around 2% of the UK energy market (however that still equates to 200,000 properties) and district heating will be become increasingly important to the UK in the future. In 2013 the Department for Energy and Climate Change (DECC) developed a heat networks model with initial estimates suggesting that the 2% share in domestic heating could be increased to 20% by 2030.

In the UK shared heating networks were first used in urban areas, predominantly in blocks of flats in the 1960s and 1970s (many of these schemes are still in operation today). For a number of reasons, particularly due to the decreasing popularity of high-rise housing developments during the 1980s and 1990s, heat networks fell out of favour somewhat. Since 2000, as energy prices have risen, and government has looked for ways to cut carbon emissions the financial case for heat networks has greatly increased.

At Mibec we are specialists in District Heating and have a great range of products to enable the customer to assemble their systems. Buffer tanks and vessels of up to 200,000 litres are possible with our bespoke design service (tanks of this sort of size would be ideal for district heating schemes).

The central heat source will then be connected to the various buildings in the scheme via an underground pre-insulated pipe network to maintain the water temperature when in transit (avoiding heat losses to improve energy efficiency). Traditionally district heating schemes in the UK have used steel pipework to meet the high operational temperatures that are needed to compensate for their heat losses over large distances. Plastic pipes however, despite lacking the very high operating temperature of steel pipes, are starting to become very popular due to their improved flow characteristics and superb insulation performance allowing for lower temperatures to be used at the heat source – improving energy efficiency across the system. We offer a wide range of plastic pre-insulated pipes from leading district heating pipe manufacturers like RehauMicroflex or our own Mibec DHP pipe.

Where the buildings within the district heating scheme are individual properties or dwellings then our range of Heat Interface Units (HIUs) are a perfect solution. Each home or apartment has its own HIU installed, which uses heat distributed from the central network to provide heating and hot water for use in the home, replacing the requirement for individual boilers in each property. HIUs include individual accurate metering which makes billing for the occupants fairer and makes it easy for landlords to manage large portfolios of properties.

We offer a full free of charge specification service covering the whole of the UK, designed to support architects, specifiers or contractors, helping you to select a full heating system to meet your needs. Please feel free to email or call our support department on 01948 661639 where one of our trained advisers will be happy to help you.