Thinking About ASHPs

Air source heat pumps (ASHPs) are a type of renewable energy technology that can be used to heat and cool business properties.

Air source heat pumps leverage well-understood refrigerant circuit technology that is employed in your domestic fridge, but rather than cooling, the system is reversed to extract usable heat. They work by transferring heat from the outside air to the inside, using electricity to power a compressor. ASHPs are more efficient than traditional heating and cooling systems, and they have the potential to save businesses money on their energy bills and importantly will reduce carbon emissions generated by buildings.

The first step is to draw in the outside air. This air is then passed over a network of tubes filled with a refrigerant, which is a special type of fluid that can absorb heat. The refrigerant absorbs heat from the air, which causes it to change from a liquid to a gas. The gaseous refrigerant is then compressed by a compressor, which increases its temperature. The hot, compressed refrigerant is then passed through a heat exchanger, which transfers heat to the water in your home’s heating system or hot water cylinder. The now-cold, compressed refrigerant is then allowed to expand, which causes it to return to a liquid state. The liquid refrigerant is then pumped back to the beginning of the cycle, and the process starts all over again.

At Adveco we use ASHPs to supply preheat heat for domestic hot water (DHW) demands in commercial properties, such as washroom facilities, shower blocks, professional kitchens, laundry, and hot water demands for multiple occupancy sites like hotels, care homes and schools.

As a low-carbon technology, ASHPs are a more efficient and environmentally friendly way to heat water for businesses than traditional gas-fired water heaters and boilers. They can help to offset currently more expensive electricity demands generated by primary heat sources such as electric boilers and in particular immersions which were not intended for extended, regular usage in larger scale systems. Designed and installed correctly, ASHPs will help to reduce carbon dioxide emissions as part of a decarbonisation strategy, but, due to the need to work current iterations of the technology harder to attain higher working flow temperatures needed in commercial applications, efficiency drops and the operating costs of the ASHP unit will climb. Compared to an equivalent gas-fired system, current ASHPs will be more expensive to operate based on current gas and electricity prices.

ASHPs are also relatively expensive to purchase. The government’s heat pump plans are based on market expansion to lower prices as mass adoption takes place over the course of the next decade. However, since the technology employs components that are already mass-marketed by the cooling industry, which far outweighs heat pump sales, the expectation within the industry is for ASHP capital costs to remain relatively static, especially across the commercial sector. Improvements in refrigerant efficiency will increase efficiency and it is hoped reduce the size and complexity of future units which could ultimately help lower purchase costs.  One way to address the capital costs of investing in ASHP is to fully review the water heating system, especially if ASHPs are intended to replace existing gas-fired systems. In many cases, DHW systems are oversized, with multiple ASHPs specified as replacements when a single ASHP for preheat and a lower-cost electric boiler would deliver the same operational needs.

Under the right circumstances, ASHPs can bring multiple benefits to a commercial organisation adding an easy-to-maintain renewable energy source to a building, improving system efficiencies and crucially reducing emissions. If you are considering installing an air source heat pump, there are a few things you need to keep in mind when applying the technology to water heating. Unlike space heating, you do not need to consider the levels of insulation in the buildings, so ASHPs are advantageous for both new build and refurbishment properties.  Second, consider the actual hot water demands of your buildings as this will influence decisions on the size or the number of heat pumps required to meet occupant demands. You want to size a system to meet those demands without oversizing the heat pump which will prove more expensive to buy and operate. For existing properties consider metering usage before committing to a design, Adveco can help with the temporary installation of flow meters, data interpretation and correctly sized design.

For information on Adveco’s FPi32 and L70 ASHP ranges and hybrid systems from Adveco visit our heat pump product pages