More and more states and cities across the U.S. are mandating alternative energy sources over fossil fuels such as natural gas. As a result, the HVAC industry is increasingly interested in alternative energy sources for heating and cooling equipment. One alternative technology that has worked well in residential HVAC applications but has only recently started to be used in commercial buildings is the air-source heat pump (ASHP).

Please visit our website for more information on this topic.

Improvements to ASHP technology have made it a viable and effective option, especially where natural gas use is restricted. Here are answers to three common questions about this technology.

1. What Is an Air-Source Heat Pump and How Does It Work?

A heat pump is an HVAC unit that moves energy to heat or cool depending on the need. The energy moved by heat pumps has typically come from geothermal energy in ground or water sources. Some heat pumps use waste energy created in a factory. Now, improvements in heat pump technology can generate heating and cooling energy from ambient air.The primary parts of ASHPs are:

• An outdoor coil and an indoor coil
• Compressor(s) to pump refrigerant
• Outdoor fan(s) to move ambient air across the outdoor coil
• Indoor fan(s) to move supply air across the indoor coil
• An expansion device to regulate the flow of refrigerant and maintain pressure and temperature
• A reversing valve to offer both heating and cooling

Liquid refrigerant absorbs heat from the air and evaporates into a gas. As the gas moves through the compressor and its pressure increases, its temperature rises. The gas then condenses back into a liquid as its heat energy is released. Using the reversing valve, the system can either:

• Absorb heat at the indoor coil and release it to the ambient air at the outdoor coil, providing indoor cooling, OR
• Absorb heat at the outdoor coil and release it to the supply air at the indoor coil, providing indoor heating.

Our air-source heat pump application guide goes into more detail about how ASHPs work and how to design them to maximize their benefits.

2. Can Air-Source Heat Pumps Function in Cold Weather Climates?

The two heat pump technologies that offer the most potential for commercial buildings are geothermal and air-source. In deciding which to use, it is important to consider that geothermal heat pumps require access to thermal energy generated by the Earth. This can mean finding a large area of land or water to accommodate the closed-loop pipe system needed for operation. Commercial facilities in rural or suburban locations may have access to the additional land necessary to install geothermal systems. However, geothermal heat pumps seldom work for buildings in densely populated urban areas where land is scarce.

Air-source heat pump technology does not require a geothermal field closed-loop pipe system. It accomplishes heating and cooling by simply transferring energy between ambient air and supply air. The outdoor coils replace the need for the extensive piping required for geothermal heat pumps, making it unnecessary to have a large land footprint around the building.

Selecting the Best Heat Pump Option

DOAS HVAC

Countless coverage has been dedicated to domestic air source heat pumps across news and social media platforms, some of it with a negative bias.  There’s the high cost in comparison to a gas boiler, the difficulties of retrofitting heat pumps into older, poorly insulated properties, plus a lack of skilled installers.  But whilst the media storm rages, larger heat pumps designed for commercial properties are being successfully installed across the UK, delivering heat and, step by step, transitioning us towards decarbonisation.

Are commercial heat pumps different to domestic ones?

All air source heat pumps work on the same principal of using a refrigeration cycle to transfer heat from external air and using it for heating and in some cases, hot water within a building.

Link to Zhongkeneng

To explain in more detail: a fan passes ambient air over extremely cold liquid refrigerant.  The refrigerant captures the heat from the ambient air and becomes a warm vapour.  That vapour passes through a compressor which produces hot refrigerant.  The heat in the hot refrigerant is then transferred to the heating and hot water system through a heat exchanger.  After the heat is transferred the refrigerant passes through an expansion valve which reduces its temperature, making it really cold again and enabling it to capture heat from the ambient air, continuing the cycle. 

Even when it’s very cold outside, down to minus 20°C a heat pump will still work and will still deliver heat, although at minus external air temperature figures it does have to work harder and is therefore less efficient.

Both domestic and commercial heat pumps work in this same way, but with commercial heat pumps the units are understandably larger and more powerful.

Where can commercial heat pumps be used?

Commercial heat pumps have a wide range of commercial and industrial applications, including new build, refurbishment and retro-fit:

• Schools 
• Retail premises
• Warehouses 
• Office blocks 
• Leisure facilities
• Apartment buildings (including those operating a heat network or district heating)
• Sites requiring low GWP (Global Warming Potential)
• Clients with net zero commitments
• Buildings with Part L requirements

Any commercial building can benefit from a heat pump as long as it has effective insulation, external space for the heat pump unit, and the unit is correctly sized, as well as having access to a sufficient electrical supply.  Thermal insulation is key here as without it the system will need to overcompensate to maintain a steady temperature.

Another important consideration, is the radiators. Heat pumps operate at lower temperatures to gas boilers, so ideally larger radiators are required to get the best efficiency from the heat pump and to effectively heat the building.  This may mean replacing the radiators, which is a cost that needs to be factored in.

What are the benefits of a heat pump for commercial buildings?

Heat pumps have many benefits when it comes to commercial properties.  Let’s look at each of these in turn:

1. Heat pumps are very energy efficient.  Heat pumps can be up to 500% more efficient than traditional boilers.  That means they can operate up to almost five times more efficiently, and have the potential to produce up to five units of heat for every one unit of electricity that they use.
2. Heat pumps produce renewable heat.  Heat pumps utilise the free energy in the air to heat water in your heating system.  The heat from the air is transferred rather than generated.  When they are partnered with a renewable electricity supplier, heat generation is 100% carbon neutral.
3. Heat pumps have significantly reduced carbon emissions.  Heat pumps use a small amount of electricity to power the transfer of heat from the environment to the building, and as a result emit no direct CO2 compared to traditional gas boilers or direct electric appliances. It is estimated that this reduction in carbon emissions is around 65-70% in commercial buildings.
4. Heat Pumps require little maintenance.  Heat pumps are a closed loop system and rarely require maintenance.  When installed correctly, a commercial heat pump system can easily last for several years.

Ideal Heating’s range of ECOMOD monobloc air source heat pumps have been specifically designed for use in commercial applications.  They are available in a choice of refrigerants – R32, R290 and R744 – and can be used alone or cascaded to meet the heating requirements of larger buildings. Each model in the range will suit commercial situations more than others, whilst also combining with alternative Ideal products, such as the EVOMAX 2 and the IMAX XTRA 2 commercial condensing boilers, to build a low carbon hybrid heating system.

Are you interested in learning more about air source heat pump commercial? Contact us today to secure an expert consultation!