The role of the heat pump in the journey to net zero

With rising energy tariffs and increasing awareness of our environmental impact, maximising energy efficiency plays a key role in helping to lower operational costs and meet the required regulations.  While it is, without doubt, a difficult time, some steps can be taken, which can also help to accelerate the transition to the UK government's Net Zero goal for 2050.

Regulation driving change

The ‘Heat and Buildings Strategy’ launched in October 2021, is the UK Government’s plan to decarbonize heating as much as possible in all buildings and is fundamental to the Net Zero goal. At the heart of this low-carbon heating strategy is phasing out the use of fossil fuels to heat buildings by 2035, whilst increasing the application of low-carbon products, fuels, and energy sources.  

The uplift of Building Regulations ‘Conservation of fuel and power: Approved Document L’, introduced in December 2021 and in force as of June 2022, is the legislative method adopted to ensure new commercial buildings will be fitted with low-carbon heating and high levels of energy efficiency achieved. Under the new framework, decarbonising heating is key to cutting emissions across commercial buildings.  

If we look past the fabric and focus solely on the building heating system, one of the main points highlighted in the latest regulations states that a heating system must be designed to work at 55ºC flow. This new legislation is a big contributor to the Net Zero goal and will effectively mean an end to like-for-like commercial boiler replacements and will eventually phase out the use of non-condensing units in new and existing buildings altogether, except under exceptional circumstances. This means that only high efficiency condensing gas boilers will meet the minimum requirements. However, when it comes to sustainability, there’s no doubt that heat pump systems play a key role towards achieving the Net Zero goal.

How do commercial heat pump systems work? 

Air source heat pumps gather heat energy from the surrounding air which, via a heat exchanger, is transferred into the heat pump’s refrigerant and turned into vapour. The vapour is passed through a compressor and turned into high pressure, high temperature refrigerant, raising the temperature to a point that can deliver heat throughout a building's heating system. Air Source heat pumps don’t require high external temperatures to function; they can continue to operate with external air temperatures down to -20ºC. 

What makes heat pump technology energy efficient?

Heat pump systems are up to three times as efficient as a gas boiler. Heat pumps change low grade heat into useable heat, with the most popular type being the Air Source Heat Pump. This uses a small amount of electrical energy to transfer the ambient heat in the air outside of a building and move it inside, where, at a higher temperature it can then be used for the building heating system including underfloor heating, radiators, or maintaining a supply of hot water.

Delivering up to 4 kWh of energy for every 1 kWh of electricity used to power it, air source heat pumps can be 300 to 400% more efficient than electric heating alone. But the benefits don’t end there. In addition to providing a controlled climate with improved air quality, once correctly installed by a qualified commercial heating installer with maintenance in line with manufacturers recommendations, a heat pump could last between 10-25 years, or more.

Different types of heat pump systems 

Air source heat pumps are divided into two types: split and monobloc units. A split heat pump has both an outside unit (incorporating the heat exchanger and compressor with pipework containing refrigerant connecting to the internal hydrobox). A monobloc heat pump contains all the refrigerant components in the outdoor unit, leaving more space inside the property. The benefit of this means monobloc heat pump units are easy to install and maintain.

Features to consider 

Accurate control of any heating appliance is crucial to efficient operation, so ensuring appliances are sized to meet the correct load requirements of the building is the first step.  

In terms of efficiency, we also need to consider the COP (Coefficient of Performance) of an air source heat pump. The higher the CoP, the more efficient the heat pump, which equals lower cost operation

Controls are another important feature, particularly when it comes to unpredictable UK weather. Here, a monobloc heat pump with an inverter controller compressor will adjust accordingly and accurately meet the heat demand of a building.

Refrigerant is also a vital component of a heat pump and is an important factor to consider when it comes to determining sustainability. Heat pumps that use refrigerants with a low Global Warming Potential (GWP) should be a priority. The Tyneham range of monobloc air source heat pumps from Hamworthy Heating, for example, uses R32 refrigerant which has a very low GWP and a zero Ozone Depletion Potential (ODP), R32 refrigerant, compared to other traditional refrigerants.

Lastly, when it comes to specifying a heat pump, consider brand reputation and look for a manufacturer that provides backup and long-term reliable technical support and customer service.

For more information on the basics of heat pumps, contact your Area Sales Manager about completing our CIBSE approved CPD: Intro to heat pumps - technology and principles