Despite enthusiasm in Whitehall for heat pumps they not the best way to upgrade a rented property's EPC rating, a new report has claimed.

epIMS, the EPC and energy efficiency platform developed for landlords, says heat pumps are more energy efficient but more expensive to run.

This is because they use electricity, which tends to be more expensive than gas both in terms of raw energy prices (£0.2450 vs £0.0624 pence per kWh) and standing charges (£0.6099 vs £0.3166 pence per day).

Based on an average household and set-up, a gas boiler holds an efficiency (coefficient of performance) level  of 85% and uses 11,212 kWh in energy per year. In comparison, a ground source heat pump uses 2,383 kWh and boasts an  efficiency level  of 400%, whilst an air source heat pump is rated as being 300% efficient and uses 3,177kWh.

As a result, the total estimated annual bill for heating and hot water when using a ground source heat pump is £806, just £9 cheaper than a traditional gas boiler, whilst heating a home with an air source heat pump will set you back £1,001 a year on average.

The company has also revealed the number of heat pumps installed in UK homes so far. Some 113,555 government-supported heat pump installations took place across the UK over the last five years.

And during the second quartr of this year, some 9,871 were installed versus just 2,461 during Q2, 2019, with a 41% increase in the number of heat pumps installed in the last 12 months alone versus the previous 12 months.

The vast majority (99%) of these installations were air source heat pumps, with this remaining by far the most common option over the years.

EPC ratings

“Whilst an Air Source Heat Pump is more environmentally friendly than an efficient gas boiler and in the right circumstances can be less expensive to run, they currently don’t improve most EPC ratings,” says the firm’s COO Craig Cooper (pictured).

“As a consequence, landlords need to look carefully at what improvement measures contribute towards a C rating, which is widely expected to become mandatory by 2030.”