Renewable Energy Heat Pump Experts
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Top tips

Insulation is King

APS Energy Solutions can provide heat pump advice on how a heat pump works and best installation practice, including top tips for self builds and renovations. For a good ground source heat pump installation on a new build property, insulation is key.

For renovation projects in particular, the better insulated your home the more efficient it is to heat, which means smaller energy bills. Your home’s efficiency will also impact the size of the heating system you require – the lower your heat demand, the smaller and cheaper the heating system, and the less work it needs to do, which all in all means a far cheaper to run home.

Insulation is the single most important aspect of any building. It is the easiest way to reduce any buildings heating costs and as energy prices spiral, fitting good quality insulation will save energy, reduce fuel bills and reduce carbon emissions.

Reach for the stars

Selecting whether you have underfloor heating or radiators, and what floor covering you use, can all effect what the industry call your ‘system star rating’. The more efficient your selections, the higher your star rating, which ultimately means lower fuel bills.

Typically well insulated homes with underfloor heating downstairs and radiators upstairs (oversized if a renovation) return the best results.

Sizing it right

In in order that an accurate ground source heat pump sizing can be determined all properties, regardless of the insulation levels, will need a full MCS heat loss calculation.

For this process at APS Energy Solutions costs around £150 – £200. If a heat pump is too small then the running costs will increase, too large and the heat pump could cycle on and off.

Our MCS service includes a full MCS heat loss calculation.

Can't insulate? Go bi-valent

If there is no opportunity to improve the fabric insulation of the building a supplementary heat source could be used. This is known as a bi-valent installation, (or bi-vailent as it can be spelt), where the existing boiler is retained to meet the peak demand of the building at the coldest times. 

As the boiler operates at a higher flow temperature, when in operation it will take the full load of the property effectively holding off the heat pump until it is capable of providing the level of comfort required. 

This can be done manually through time clocks or a more sophisticated automated system could be employed using external thermostats.

Bi-valent installations can be effective, however a great deal of consideration needs to be given to the value of installing the heat pump in un-insulated buildings due to the capital cost involved, considering the running cost savings are likely to be marginal and the system performance may decrease in comparison to the existing boiler system due to the lower flow temperatures in the radiators.

Working with radiators

Most retrofit applications will have a night storage or radiator heating system. In order to obtain heat from a radiator the outlet temperature of the heat pump needs to be increased to approximately 45°C – 50°C, which can often mean a larger heat pump is required. 

This is because as the outlet temperature of the heat pump increases, its efficiency decreases. The reduction in efficiency will reduce the running cost benefit of the heat pump.
As radiators in retrofit properties are typically sized for a flow temperature of 71°C – 82°C, they may well be undersized to work with a ground source heat pump (which requires a flow of around 50°C). Therefore the radiators might need replacing.

To understand what the maximum output of the radiators are at the reduced temperature and whether they are large enough.

Things to note:
- Any microbore pipe to the radiators would need to be replaced.
- Off peak tariffs cannot generally be fully utilised as radiators do not have any storage capabilities.

Kensa umbrella

APS Energy Solutions are approved partners of Kensa with full MCS accreditation