All you need to know about heat pumps
The Government is offering a £7,500 grant towards an air source heat pump via its Boiler Upgrade Scheme. Here we take a look at how the pumps work and why they are eco-friendly.
WITH Government steering us towards net zero by 2050, the days of gas-powered boilers are numbered. That’s because UK homes emit more
CO2 than the nation’s cars, which makes home heating a primary part of the UK’s carbon reduction plans.
The competing concerns of climate change and affordability for householders have already caused several policy shifts but as things currently stand, non-renewable heating installations will be illegal in new-build homes from next year. This looks set to be widened to all homes from 2035.
It doesn’t mean you will have to scrap your gas or oil-powered heating system immediately but when it expires homeowners will have to replace them with renewable alternatives.
This puts the focus squarely on heat pumps, which offer the most efficient low-carbon alternative to gas-fired boilers.
The Government has an ambitious target of 600,000 annual heat pump installations by 2028, hoping that a grant of £7,500 via its Boiler Upgrade Scheme will drive take-up.
But how can you tell if the new funding makes a heat pump a good investment now and how do you know whether it is the best solution for your home? Then there is the conundrum of which type of heat pump you should choose.
A heat pump can work in virtually any home with outside space and you can choose between an air source heat pump and a ground source. The latter are more expensive but very efficient.
Sheffield homeowner Rob
Ritchie recently opted for an air source heat pump in his threebedroom, 1920s detached house to regain control of spiralling energy bills.
He says: “Most UK heat pumps are down South where temperatures are three degree Celsius warmer, and my house is not modern but we are operating towards the top of all installations nationally. If you can do it here in my home, you can do it anywhere.”
With solar photovoltaic panels and energy storage batteries in the mix too, he now pays nothing for heating and hot water and generates income by selling excess electricity to the grid.
His Viessmann Vitocal 150-A heat pump runs at an impressive CoP of 4.95, which stands for Coefficient of Performance.
In Rob’s home it means that for every kilowatt of power used, the air source heat pump generates 4.95kW of heat.
To work efficiently, heat pumps need highly insulated buildings as excessive heat loss means a larger, more expensive appliance, costing more to run.
Air source heat pumps also work best with lower temperature heating systems like underfloor heating or large radiators, plus they must
adjust operating temperatures to outside conditions for maximum efficiency.
Getting a qualified, experienced installer to do a heat-loss calculation is a crucial first step when considering whether to invest in a heat pump.
This involves measuring rooms and windows and assessing insulation levels to identify the correct size and type of heat pump and associated running costs, so you can
forecast when you’ll get a return on your investment.
Your installer should advise on any changes needed to make your property heat-pump ready. That might include wall or loft insulation, double or triple glazing, radiator and piping upgrades or underfloor heating.
While ground source is often the most efficient choice in very cold areas, unless you have 600-1200m2 of land to lay horizontal pipes, you will need to drill a deep bore hole, e.g. 100m is an average depth.
The expense and disruption of either scenario often rules out this option. So air source will likely be your most viable solution.
That requires sufficient room for both indoor and outdoor units on an outside wall. They are similar in size to washing machines. You will also need an indoor hot water cylinder, accessible for servicing.
Finding an installer with the necessary expertise is essential, so do your research. “Just because someone fits boilers, it doesn’t mean they can install a heat pump,” says Rob Ritchie. “There’s more science involved.”
He selected Sheffield-based specialists Blakemore Plumbing, Heating and Renewables, following a recommendation from another local heat pump owner.
“It was a great choice. There’s massive advantages to becoming energy independent. My carbon footprint is virtually nothing and I definitely have no regrets.”
A typical air source heat pump installation is around £14,000, according to www.energysavingtrust. org.uk/advice/air-source-heatpumps. www.blakemoreplumbingandheating.co.uk