When investing in a ground source heat pump system you’ll want to make sure it runs as efficiently as possible. James Coe at Kensa Heat Pumps shares how to get the most out of your low-carbon heating installation

WHAT FACTORS MAKE A GROUND SOURCE HEAT PUMP INSTALLATION EFFICIENT? 

Heat is better contained inside an insulated building because the heat loss to the outside is lessened, reducing energy demand. Any heating system will operate better in an insulated home, however, ground source heat pumps (GSHP) will also operate in properties with lower insulation levels. It is important that the pipework is insulated, so the heat isn’t lost before it gets to radiators or underfloor heating.

Another factor is ensuring you use a well-designed system – and that you install it properly. The focus should be on the design and commissioning of the ground arrays and collectors. Ground source heat pumps operate most effectively with low-temperature heating distribution systems.

The heat source used also determines its efficiency. Shallow (ground array) trenches are usually an ideal source for properties in rural areas or any building with a decent amount of surrounding land. Vertical boreholes are particularly good for properties like tower blocks, flats, businesses, or homes with limited useable garden space. Water can be one of the most efficient sources of heat transfer and is suitable for any property close to a water source, including lakes, ponds, rivers, the sea, and even aquifers.

The heating distribution system and its size is another factor. Ground source heat pumps deliver heat through a variety of heating systems. Underfloor heating is a very effective way to heat a property and works especially well with a ground source heat pump; systems have a large surface area and therefore can operate at lower flow temperatures. Radiators can also operate with ground source heat pumps, however they do need to be correctly sized to operate at the lower flow temperatures which the heat pump requires (45ºC -50ºC).

HOW EFFICIENT IS A GROUND SOURCE HEAT PUMP COMPARED WITH OTHER HEATING SYSTEMS? 

As an eco-friendly alternative to fossil fuels, a ground source heat pump delivers the ideal low-carbon heating. Air source and ground source heat pumps differ in efficiency, running costs, carbon savings and durability.

The inherent efficiency of ground source heat pumps means they can deliver the lowest running costs of any type of heating system. As the ground temperature remains constant all year, between 8°C and 12°C, there are no unexpected spikes in electricity use as there would be with an air source heat pump on a cold day. The initial upfront cost savings of an air source heat pump could be quickly negated by higher maintenance and running costs due to lower efficiencies and shorter lifespan.

Modern condensing boilers can be over 90% efficient, however, ground source heat pumps can achieve efficiencies of 400%. The difference in efficiency is significant because, unlike boilers, heat pumps deliver more energy than they consume – specifically from electricity.

HOW CAN AN EFFICIENT GROUND SOURCE HEAT PUMP SAVE ME MONEY?

Systems that deliver much more heat energy than they consume will provide households with the lowest running costs. Government funding can also be used to offset the additional cost of installing a heat pump in domestic projects. Ground source heat pumps can also save money by utilising time-of-use tariffs and specific control systems by consuming power when electricity is cheapest, due to their unique ability to ‘load shift.’

HOW CAN AN EFFICIENT GSHP SAVE CARBON? 

Efficient ground source heat pumps can deliver over 4 kW of renewable energy for every 1 kW of electrical energy they use. If you can use electricity from renewable sources, you have the ability to cut carbon emissions completely.

Ground source heat pumps emit no point-of-use carbon emissions or air pollution, and their load-shifting capabilities mean that they can move their consumption to not only the cheapest time but also the lowest carbon.

WHAT ARE THE TOP TIPS FOR AN EFFICIENT GSHP INSTALLATION? 

For most system installations, improving efficiency starts with insulation. The more insulation a property has, the better it will be at retaining heat. Modern homes already have insulation, which helps save on energy bills.

Underfloor heating and radiators can have an impact on the efficiency of a heat pump. Underfloor heating works efficiently with a heat pump because larger surface areas are compatible with low flow temperatures. And the lower the temperature required of the heat pump, the less work it has to do to get there.

When well designed, heat pump systems will provide an efficient, cost-effective heating solution for all your heating and hot water needs – however their design is key, so do engage with your heat pump specialists and other renewable system manufacturers (if required) at an early stage to ensure all details are discussed and addressed early on.

James Coe is sales manager at Kensa Heat Pumps