Heat Pump
Discover the perfect balance of comfort and efficiency with our advanced heat pump systems built using quality HVAC parts. Designed to provide both heating and cooling, our systems deliver consistent performance, lower energy costs, and year-round reliability.
Designing Heat Pump Systems for a Low-Carbon Future
Heat pumps are now in the limelight thanks to their recognition in government-backed schemes such as the Green Homes Grant and the Renewable Heat Incentive. With zero emissions at point of use, there is no doubt that they are perfectly placed to help drive down carbon emissions from domestic heating. However, it is essential to design a heating system with ground and air-source heat pumps correctly to enable them to deliver the carbon and energy savings promised. What’s more, it is important to understand how these systems can be taken one step further so that their carbon-reduction potential can be maximised for future residential developments.
Size matters
Many crucial aspects of heat pump design are related to the low and medium flow temperatures of these systems, such as sizing and controls. Unlike traditional solutions which operate at anywhere between 60 to 85 degrees, any flaws in the design of a heat pump system will result in more noticeable consequences, such as higher electricity bills and lower levels of comfort.
This is why extra attention is needed when calculating pipe sizing and flow rates. Lower flow temperatures and lower temperature differentials for heat pump heating systems mean that more water going through the pipes is needed to ensure sufficient heat transfer. Correctly calculating the system will ensure that the pipework and heat emitters such as radiators will be appropriately sized so that a space is warmed to the desired temperature.
A balancing act
Because water takes the route of least resistance, it wants to flow to the first radiator and not the last in the hydraulic circuit. This is why it is crucial to correctly carry out hydraulic balancing at the commissioning stage so that all heat emitters in a property get the required amount of heat, including the last. Unbalanced systems can lead to higher system return water temperatures, reducing the operational efficiency of the heating system and can also impact on the customer’s comfort.

In essence, hydraulic balancing ensures the flow of water is balanced across all radiators in the system, so that each one receives the right amount of water and therefore heat. It is the final piece of the puzzle in delivering a well-designed, installed and commissioned heating system.
Stay in control
With a traditional high temperature system, the boiler fires up to heat a building to the required temperature quickly. Heating solutions designed to run with lower flow temperatures need to be on for longer, which is why setting up the controls in the correct way is paramount to enable the system to perform efficiently. We recommend using ‘comfort’ and ‘set back’ temperatures. The former is usually around 20-21oC, the latter for night time or when occupants are out of their home or building, at around 16-17oC. Using controls with load or weather compensation will also ensure that a heating system is only on for long enough to maintain the right temperature. So, if only a small increase in energy is required to meet the set temperature, the heating system will work at a reduced output to use the minimum amount of energy needed.
More Hot Water
Most heat pumps in the market operate with lower temperatures, which means that a back-up heater (direct electric immersion heater) is required in the hot water cylinder to store hot water above 60oC – the point at which legionella bacteria is killed. However, the recently launched aroTHERM plus uses natural refrigerants which can produce higher system temperatures. This means that the flow temperature into the cylinder, directly from the heat pump, can be up to 75oC. As a result, the use of a direct electric immersion heater to protect occupants from legionella is not necessary, and users can take advantage of a more effective system which can deliver more useable hot water at point of use.This is why extra attention is needed when calculating pipe sizing and flow rates. Lower flow temperatures and lower temperature differentials for heat pump heating systems mean that more water going through the pipes is needed to ensure sufficient heat transfer. Correctly calculating the system will ensure that the pipework and heat emitters such as radiators will be appropriately sized so that a space is warmed to the desired temperature.
Heat networks
In apartment blocks, heat pumps are now commonly used as centralised heat sources within low-temperature district heating networks or ambient loops. A central heat pump supplies heat to a buffer tank, from which individual apartments draw energy through smaller connected heat pumps. This setup improves efficiency, reduces heat loss in common areas, and cuts insulation costs, as heat is only generated where needed.
Future connectivity
Fundamentally, designing and installing a heating system with a heat pump doesn’t differ a great deal from a boiler installation. Everything you should do for the latter – getting flow rates, sizing and water quality right – you have to do with the former. Systems with heat pumps may be less forgiving to faults in their design and installation, but with greater potential to deliver heat with zero emissions at point of use to many more people, they are paving the way towards decarbonising heat in our homes of the future.