Heating and Ventilating

With interest in gas absorption heat pump technology continuing to grow, Stefan Gautsch outlines typical applications for the technology
Gas absorption heat pumps are a relatively new concept for the UK market, but represent an effective way of keeping emissions and fuel costs to a minimum for both new build and refurbishment projects. As the technology uses gas, which is around a third of the price of electricity, running costs can be cut significantly.
On top of this, around 65 per cent of additional heat can be generated by drawing in free energy from the surrounding air.

The technology also has the versatility of being able to work as either a standalone system, or combined with a condensing boiler to cater for buildings with a particularly high demand for hot water. 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, 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.

Using a gas condensing burner

A key strength of a gas absorption heat pump is that it uses a highly-efficient gas condensing burner 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 two 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. Targets for renewable technologies required for planning permission are now more demanding than ever before, which is why high efficiency levels and sustainable credentials are key to securing new build planning permissions.

Saving valuable space

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.
While 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 stakeholders a reliable source of heating and hot water.

The Display Energy Certificate (DEC) 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 play a huge part in achieving 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 deg C for the production of domestic hot water, which allows an existing plant to be updated without having to upgrade all the associated pipework and heat emitters.

As more renewable or high efficiency technologies come onto the market, there is a greater need for investors to take a thorough, considered approach to making a decision on which technology will make the biggest savings, both in terms of emissions and fuel costs.

A gas absorption heat pump is a viable option for a wide range of applications, whether new build or refurbishment, particularly as we work towards achieving the Government's energy efficiency targets.

// The author is senior commercial technology consultant at Buderus, Bosch Group //