Comfort cooling – district cooling

The demand for cooling in buildings is increasing. The reasons are, besides the demand for comfort, the improved insulation of buildings nowadays and the increasing number of heat-producing Machines as computers and other Electronic Equipment. This provides district heating companies with new business opportunities based on the same concept as district heating where cooling is produced centrally for subsequent delivery to customers.

District cooling began to be installed in the beginning of the 90s, and today a total of 900 GWh are supplied in Sweden. There are many different ways to produce district cooling, but they all have one thing in common ‒ environmental impact and electrical consumption are minimal compared to cooling provided by means of local chillers. District cooling plants operate more efficiently and professionally, often using biofuels and other fuels that do not contribute to the greenhouse effect. For society as a whole, district cooling offers many environmental advantages and helps to husband natural resources.

Absorption chillers

Heat-driven chillers, absorption chillers, provide one way to produce cooling. Waste-to-energy and heat and power production are steadily increasing but generate much surplus heat from March to October which has to be cooled down. Absorption chilling technology makes it possible to use this surplus heat from these plants during this time period.

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There are major advantages with this technology compared to conventional electrically-driven chillers, as surplus heat can be used instead of electricity. For district heating companies with cogeneration plants, the demand for heat-driven cooling means that environmentally sound district heating can be produced for an extended period during the year, even if the need for comfort heating falls from March to October. This is especially interesting in systems with waste-to-energy.

Our hot water driven absorption chiller of Twin-design is developed in order to be able to be driven with low temperatures down to 70 ⁰C, which district heating companies require in order to reduce the temperatures in their district heating systems. The Twin design consists of two chillers in one chiller connected in series providing better efficiency and increased DeltaT. By that the return temperature back to plant is reduced, which is also something that the district heating companies want.

General concept

Absorption chillers use district heating as the energy source to cool a district heating circuit. The inlet energy from the district heating and district cooling is cooled either in a cooling tower, in dry coolers or in a watercourse.

Large units can be placed centrally to supply large district cooling systems, while small units can be located in buildings that require cooling and connected to a local cooling system.

Our chillers are available in 100 kW to 5 000 kW.