With the interest in gas absorption heat pump technology continuing to grow amongst contractors, consultants and specifiers, Stefan Gautsch, Senior Commercial Technology Consultant at Bosch Commercial and Industrial Heating, outlines some of the typical applications for the technology, while also explaining how it can assist compliance with key legislation and energy targets.
Gas absorption heat pumps are becoming more prominent in the UK market as the technology represents a truly effective way of keeping emissions and fuel costs to a minimum for both new build and refurbishment projects. As the technology utilises gas, which is around a third of the price of electricity, running costs can be cut significantly in comparison to the use of other comparable technologies, such as electric heat pumps. With around 65% of additional heat generated by drawing in free energy from the surrounding air, this further enhances the overall efficiency of the system in operation.
The technology also has the versatility of being able to work as either a standalone system, or as a combination with other heat sources like solar panels and high efficiency condensing boilers – subject to site requirements and conditions. Much has been said about the need for us to switch our attention towards hybrid heating solutions as we take the next step towards a full-scale adoption of renewable technologies. This will allow appliances to be partnered with the strength of a condensing boiler to make the investment worthwhile.
Generally speaking, a gas absorption heat pump is well suited to applications which have a consistent demand for hot water, such as schools, colleges, care homes, residential properties and sports facilities. These offer optimum conditions for maximising efficiency by constantly demanding hot water all year round. Even in winter temperatures, gas absorption heat pumps can achieve higher system temperatures and remain efficient. Perhaps surprising to many, is that atmospheric air stores solar energy even when temperatures are below zero. As a result, the benefits of the heat pump technology offer a practical solution all year round.
New build credentials
A key strength of a gas absorption heat pump is that it uses a highly efficient gas condensing heat generator to convert the energy from natural gas into usable heating or hot water for a building. By using gas as its primary energy source directly at the point of use, rather than electricity which is generated largely in coal or gas-fired power stations, the gas absorption heat pump has a significantly lower carbon footprint than comparable equivalents.
The result of a minimised carbon footprint is the strengthening of the appliance’s suitability for new build projects in particular thanks to a compliance with Part L of the Building Regulations. The introduction of these new requirements, which were laid out almost three years ago to govern the conservation of fuel and power, mean that stringent emissions targets are now in place. As a result, high efficiency heating technologies such as a gas absorption heat pump should be considered key components of the make-up of a building during the original planning stages.
In addition to the ability to strengthen Part L compliance credentials, gas absorption heat pump technology also minimises NOx emissions to qualify for BREEAM 5. Renewable technology target requirements for planning permission are now more demanding than ever, which is why high efficiency levels and sustainable credentials are key to securing new build planning permissions.
Another favourable trait of a gas absorption heat pump is that thanks to the units being designed for external installation, there is no need for the appliance to be housed in an internal plant room, which is likely to take up valuable space. With this comes the lack of any requirement for complex flue gas arrangements or bulky fuel storage points, which again take up valuable space within a plant room.
Whilst the bar has been raised when it comes to energy efficiency requirements for new build projects, there are also now a number of schemes in place to govern energy provision in existing buildings. Gas absorption heat pumps have, in the main, been designed to comply with the majority of these initiatives in order to offer installers and specifiers a reliable source of heating and hot water that will also impact favourably on energy targets.
The Display Energy Certificate (DEC) is one such measure which has been introduced to display an operational rating on the A to G scale and is provided alongside a breakdown of the CO2 emissions of the building. As a result, it is essential to have a well matched high efficiency heating system in place to score highly and a gas absorption heat pump can help achieve that.
A similar principle applies when it comes to an Energy Performance Certificate (EPC), which is required for buildings that are being bought, sold or rented. Again, an EPC gives information on how a building can be made more energy efficient and reduce energy costs – a visible demonstration of efficient best practice when it comes to energy provision.
A further strength of a gas absorption heat pump, when it comes to refurbishment or replacement projects, is that it can achieve a maximum flow temperature of up to 70°C for the production of domestic hot water. This may allow, in certain circumstances, existing plant to be updated without having to upgrade the associated pipe work and heat emitters throughout the building.
As more renewable heat and high efficiency technologies come onto the market, there is a greater need for installers and specifiers to take a thorough, considered approach when deciding on which technology will provide the biggest savings, both in terms of emissions and fuel costs. A gas absorption heat pump is undoubtedly a viable option for a wide range of applications, both new build and refurbishment, particularly as we look to achieve the Government’s energy efficiency targets.