Renewable Heating FAQs

Renewable Heating FAQs

Your guide to understanding Renewable Heating FAQs

Air Source Heat Pumps FAQs

  • What is an Air Source Heat Pump? 
    An air source heat pump is an energy efficient method of heating your home or building, replacing the conventional gas or oil fired boiler. It is classed as a source of renewable heat.
  • Does the Air Source Heat Pump work all year round?
    The system performs down to air temperatures of -15°C, which means that they are more than suitable for installations within the UK. Hot water and heating can be provided 365 days a year. The hot water is produced without the aid of electrical immersions and at 55°C is more than hot enough for baths and showers.
  • How much do they cost?
    Air Source Heat Pumps cost a little more than a boiler but you will benefit from both energy bill savings and RHI income. 
  • How much will I save using an Air Source Heat Pump?
    Savings you might make every year when replacing an existing heating system in an average four-bedroom detached home with an average ASHP installation vary from around £290 to £1845 depending on the fuel type you currently use.
  • How green are Air Source Heat Pumps?
    A reduction of CO2 emissions you might make every year when replacing an existing heating system in an average four-bedroom detached home with an average ASHP installation vary from around 1.4 tonnes to 10.6 tonnes depending on the fuel type you currently use.
  • Will my Air Source Heat Pump require any special maintenance?
    A yearly check by you and a more detailed check by a professional installer every three to five years should be sufficient. The installer should leave written details of any maintenance checks you should undertake to ensure everything is working properly.
  • Are there any government incentives?
    You may be able to receive payments for the heat you generate using a heat pump through the government’s Renewable Heat Incentive (RHI). 
  • Do I need to worry about the noise level?
    The air handling unit is located outdoors and generates a similar level of noise as an American style refrigerator. For this reason, the air unit for this system is best situated a number of metres away from windows and doors to minimise any effect on neighbours. Placing the unit on a noise absorbing base will also help to reduce the problem. It should be remembered that the unit will not run as much in the summer so should be less of a problem when people are most likely to be using their gardens or have their windows open. 
  • Can I keep my existing radiators?
    If you have the opportunity, underfloor heating can be more efficient than radiators because the water doesn’t need to be so hot. If underfloor heating isn’t possible, use the largest radiators you can. Your installer should be able to advise on this. 
  • Can I heat my swimming Pool with an Air Source Heat Pump?
    For new pools an Air Source Heat Pump is ideal. For existing swimming pools the current heat exchanger would need to be changed.
  • Do I need planning permission?
    Air source heat pump installations In Wales and Northern Ireland require planning permission. In England and Scotland they may be considered Permitted Development, in which case you will not need planning permission, but the criteria are complex so it is always a good idea to check with your local planning office.
  • Can Rexel recommend the right Air Source Heat Pump for my property?
    Yes, we have dedicated teams who can calculate this for you. Please contact our Renewables Office 020 8596 7483 for further details.

Ground Source Heat Pumps FAQs

  • Do ground source heat pumps still work in the winter?
    Yes. The temperature beneath the earth's surface stays fairly constant all year round, meaning ground source heat pumps are effective throughout the year.
  • How is the pump powered?
    The ground source heat pump is driven by electricity, with up to four units of heat produced for every one unit of electricity needed to power it, subject to the flow temperatures and system design.
  • Are ground source heat pumps environmentally friendly?
    Ground source heat pumps can offer considerable long-term environmental advantages compared to other heating sources like electric storage heaters and oil boilers. Although they run on electricity, the heat they absorb from the ground is constantly replenished naturally.
  • Are ground source heat pumps efficient?
    A ground source heat pump is in general more efficient than an air source heat pump 
  • Are ground source heat pumps eligible RHI Payments?
    Yes , ground source heat pumps are eligible under the Government's Renewable Heat Premium Payment scheme.
  • What about servicing and maintenance?
    Like most heating systems they do require regular scheduled maintenance. A yearly check by you and a more detailed check by a professional installer every three to five years should be sufficient. The installer should leave written details of any maintenance checks you should undertake to ensure everything is working properly.
  • How do I know if a ground source heat pump is suitable for my home?
    In general, heat pumps are most suitable for people with a garden suitable for the ground loop, living in a well-insulated, off-gas property or in a new-build property. Please contact a dedicated Rexel customer service team member who will be able to assist you.
  • Who can install ground source heat pumps?
    Installation work should only be carried out by a Microgeneration Certification Scheme (MCS) accredited installer.

Solar Thermal FAQs

  • How much will a Solar thermal installation cost?
    This depends on your exact requirement but typically between £3000 and £5000.
  • Will I need to replace my hot water cylinder?
    In most households the cylinders do not have a spare solar heating coil, meaning a replacement would be required.
  • Does my roof need to face south?
    A south facing roof with an angle of 30 degrees offers the best annual output. However, east or west facing roofs can function well, the solar radiation in these aspects is reduced by 15–20%. In installations such as these, the collector area may be increased to compensate for the reduction.
  • Do solar thermal systems produce hot water on a cloudy/overcast day?
    Solar thermal systems would be able to provide a degree of water heating during cloudy or overcast days, but may require the use of traditional gas or electric heating systems to produce the required temperatures.
  • Do I need planning permission?
    In England, Wales and Scotland, you don't need planning permission for most home solar water heating systems, as long as they're below a certain size - but you should check with your local planning officer, especially if your home is a listed building, or in a conservation area or World Heritage Site.
  • Does the system need regular maintenance?
    Maintenance costs for solar water heating systems are generally very low - most solar water heating products come with a five-year or ten-year warranty and require little maintenance.  A periodic (3-yearly) check is recommended to check the Glycol levels and ensure everything is working properly. Once fitted your installer should leave written details of any maintenance checks, ensuring everything is working properly.
  • How long will an installation take?
    A typical domestic solar installation will take place over 2-3 days but this may vary due to many factors . Depending on the building we access to erect and remove scaffolding will also be required. Your installer can advise the specific details for your property in his quotation.

Biomass Boilers FAQs

  • What is a biomass boiler? 
    A biomass boiler is a boiler designed to burn solid fuels classed as biomass. 
  • Can a biomass boiler work fully automatically? 
    All but the smallest of biomass systems can be configured to work fully automatically. Typical automated features include time switch or optimum start/stop.
  • Does the government offer any grants or financial incentives?
    Yes. Biomass installations are eligible under the Government's Renewable Heat Premium Payment scheme.
  • How much could I save with a biomass boiler?
    Savings in carbon dioxide emissions are very significant - up to 14.5 tonnes a year when a wood-fuelled boiler replaces a solid (coal) fired system or electric storage heating. Financial savings are more variable - if you replace a older gas heating system with a wood-burning system you might save up to £80 a year, but if you are replacing an old electric heating system you could save as much as £650 per year assuming you are installing pellet central heating in a typical four-bedroom detached house with basic insulation. 
  • How big is a biomass boiler?
    Wood boilers are larger than gas or oil equivalents. You will also need space to store the fuel: somewhere that's handy for deliveries but also appropriate for feeding the boiler.