Benefits of using waste heat efficiently

Heat recovered from factories, incinerators and other commercial buildings may soon heat many UK homes.

In a recent article, The Guardian’s Energy Correspondent Lillian Ambrose describes the UK government’s intention that thousands of UK homes, offices and hospitals “could soon be warmed with surplus heat from factories, incinerator plants and even disused mine shafts under plans by the government to fund low-carbon heating.”

The Guardian reports that the government is looking to spend £30m to help set up “heat networks” across a number of cities including London, Manchester and Glasgow. It also states that: “The UK’s largest planned heat network will receive just over £12m to capture the surplus heat produced at a waste incineration plant in the London borough of Bexley to warm up to 21,000 homes in south-east London.”

This is a heat networks project on a grand nationwide scale, but this concept, also known as district heating, goes back a long way and on many different levels. For instance, as Build Energy records: “In the year 1330, the French Commune of Chaudes-Aigues (“Hot Waters”) began using geothermal energy domestically. The hottest springs in Europe provided heat for approximately 30 houses. The system used wooden pipes, with a central main and smaller channels serving each home. The method survives in the spa town today.”

The technology of heat recovery

The principle of heat recovery used in district heating networks can also work exceptionally well in individual industrial settings such as factories. For instance, Schwank has carried out a range of innovative heat recovery installations, including for Bauer in Germany.

Using the hybrid Schwank heat recovery solution, heat is recovered from the exhaust gases of Bauer’s Schwank radiant tube heating system and fed into an air-water heat exchanger. This exchanger then outputs the heat energy of the exhaust gases in the form of hot water, which is directed into a hot water storage cylinder. This supports the hot-water heating of Bauer’s offices, both saving energy and reducing carbon emissions.

A variety of initiatives of different scales of size and complexity will be required to reach the global target of zero carbon emissions by 2050. Responsible manufacturers in the HVAC sector are putting significant efforts, skills and resources into technological developments to support this objective.