High temperature heat pumps deliver carbon savings
The obvious need to reduce carbon emissions and at the same time reduce energy costs mean that heat pumps – on a commercial and industrial basis – are becoming increasingly relevant.
However, the application of heat pumps on a wider retrofit basis, to reduce energy costs and carbon emissions for existing buildings and processes, has historically been restricted due to the ‘lower than a boiler’ output temperatures of conventional heat pumps.
High temperature heat pumps are now available that can provide an answer to this temperature-based problem on both retrofit and new installations. With output temperature capability of over 80°C this next generation of air or ground/water source heat pumps can provide an energy and carbon-saving solution for both commercial & industrial retrofit or new build applications.
Applications now include gas or oil/LPG boiler replacement, district heating schemes, hot water generation and realistically any industrial or commercial heating/hot water application where energy cost savings and carbon savings are required.
High temperature heat pumps deliver temperatures between 70C and 110C which means that retrofit heating & hot water projects can be 100% heat pump driven up to 1,500kW capacity.
In addition to heating and hot water a less well understood application is heat pumps providing cooling – these systems can now be considered within retrofit energy-saving projects as a means of reducing waste energy.
Garry Broadbent of the specialist heat pump provider Pure Thermal commented: “We are now seeing an increase in demand for higher temperature systems for both heating and hot water production, the range of heat pumps we provide has seen a real increase in interest due to the output temperatures available being above 70C, the decreasing carbon content of grid electricity is favourable to heat pumps meaning that on a carbon saving basis a heat pump now stands up extremely well against fossil fuels particularly within retrofit energy reduction projects.”
Basically a site that utilises cooling for process or air-conditioning usually despatches the valuable zero carbon heat generated by the cooling process to atmosphere as waste. However the overview below describes a high temperature heat pump that is providing production cooling along with a 70C hot water output.
Garry Broadbent added: “We are now designing systems where the heat pump is providing cooling by operating alongside existing chillers. Consuming the equivalent energy required for cooling these systems also provide high temperature heat for hot water production, ‘he continues,’ for example a dual output 100kW heat pump/cooling unit also delivers 130kW of hot water which means that two outputs are provided from the input power of cooling only. Hence significant carbon savings can be achieved with an attractive payback period on the retrofit investment by displacing the energy consumed by conventional fossil fuel boilers.”
Currently in the UK, the majority of paid for zero carbon waste heat from cooling is rejected as waste to atmosphere with a net total loss to the site operator. Basically in this example the energy to deliver cooling is providing two outputs, cooling & hot water, rather than simply providing cooling only. This certainly puts a different slant with regard to the potential for heat pump application i.e. 1 x cooling input energy = 2 x outputs: cooling + hot water.
This retrofit opportunity is applicable to any application where a site has a duplicated demand for both cooling and hot water production. The message being that it is now practical to generate valuable low carbon high grade 80C hot water as a by-product of cooling using what would conventionally be the waste heat from cooling that is currently rejected to atmosphere.
Within all these potential applications summarised above it is clear that heat pumps as an alternative form of heating & hot water production are well proven and practical to both apply and use.
An increasing focus on heat pumps as being the most efficient method of delivering low carbon electric heat means that the use of this form of renewable technology will only increase as the scope of applications becomes wider.
Therefore to target carbon & energy saving applications on a retrofit basis with high temperature 80C + heat pumps appears to be a logical step.
We are now seeing heat pumps moving forward into the next stage of applications within both commercial and industrial applications delivering real benefits with significant potential to benefit carbon reduction projects on a retrofit basis.
For more info visit: purethermal.co.uk