In last month’s EM, John M Armstrong, head of operations – city energy at E.ON, shared his thoughts on the key drivers for the low up-take of heat pumps in UK homes. Guy Ransom, Commercial Director of Finn Geotherm, one of the UK’s leading heat pump companies, explains why he believes heat pumps should not be overlooked.
While it is true that the cost of oil and gas has come down compared to the high prices we’ve seen in recent years, it is important to remember that oil and gas are fossil fuels. As such, the prices will still fluctuate as they are affected by volatility in the market. While there is simply not enough green gas available to fuel boilers in every home, the electricity used by a heat pump has become greener than ever in recent years. We’ve even had some customers running their heat pumps using their own solar or wind generated power!
It is an obvious fact that any building can be heated by matching the energy loss at a given target temperature with energy input. A heat pump is simply an efficient means of supplying a given amount of energy. As such, the system can be scaled to meet the needs of a one-bedroom bungalow, perhaps 5kW, or a 27-bedroom stately home, perhaps 120kW. The key then is not the source of the heat, but the appropriate means of distributing it.
A well designed heat pump system can ably heat properties of all ages and sizes. Low EPC ratings and levels of insulation are not a barrier to a heat pump installation. Finn Geotherm has been installing heat pump systems since 2006 and includes several large, listed stately homes within its project portfolio. It is a fact that, despite the age, low EPC rating and lack of insulation of these large country houses, the occupants have been more inclined to complain of being too warm following their heat pump installation than too cold!
Heat pumps work most effectively at a lower operating temperature than combustion boilers – typically 50°C versus 80°C flow. They are also however designed to work with longer duty cycles so, rather than providing a rapid inrush of heat, energy is delivered steadily over a longer period than traditional boilers (we are very familiar with this principle in underfloor heating). In the case of older properties with thick single-skinned walls for example, a heat pump actually utilises the thermal mass of the property to heat up the entire building, effectively turning it into a giant storage heater. Safety is also worth considering here too as radiators with 80°C flow temperatures are scolding hot to the touch and so can present a risk, particularly among children and older or more vulnerable residents.
The correctly sized radiators are totally effective in working with heat pumps to maintain desired room temperatures, even in the draughtiest of buildings. Most heat pump installations do not need an entire set of new radiators – we are typically able to retain at least half of those already installed. Some customers do choose to replace old radiators anyway as part of their heating renovation project. Heat pumps work effectively with both radiators and underfloor heating.
Putting in extra insulation is not always necessary and in some properties, such as listed buildings, it is simply not viable. The Government’s latest insulation regime, which has been designed to help reduce emissions by reducing heat loss can only have a limited impact. Additional insulation and cladding can only save up to around 50% in the best possible cases. However, if we examine the system actually producing the heat and therefore the emissions instead, there is so much more potential to make a real difference. By replacing electric or gas heating with a heat pump, energy consumption can be reduced by around 75%, meaning that emissions are also reduced at the same rate. In addition, schemes to provide insulation do not deliver any additional benefit to the property owner, whereas the RHI does – and will do so for seven or 20 years.
It is true that the installation of a ground source heat pump system will be considerably more expensive than installing a traditional oil boiler, perhaps three times as much. Given the fact that a heat pump will last typically three times as long as a condensing boiler and that, during every year of its life, it will generate significant savings on heating, this additional upfront cost is more than paid for during the system’s lifetime. Coupled with the additional benefit of the RHI which is currently available, heat pumps have a relatively short payback period.
Under the DECC Energy Act 2011, landlords must ensure private rental properties have a minimum EPC rating of E. Properties which are heated properly will have an increased marketability and value so installing a good heating system is always in the landlord’s best interests. In cases where a landlord owns more than one property in one location – for example, a series of terraced houses or a set of flats, there is a great opportunity to install a district heating system. District heating enables two or more homes to be heated using a heat pump and as such will qualify for the 20 year Non-domestic RHI. We have proven with our installations for housing associations that this is also an ideal way to ensure affordable heating bills for tenants. In addition, district heating provides great benefits for the landlord in terms of servicing and maintenance as the heat pump system can be serviced without disturbing tenants. Indeed, the incidence of failure is significantly reduced too compared to fossil fuel boilers, as a district heating system uses two or more heat pumps working in tandem, so there is always a back-up in the unlikely event of a breakdown.
The ideal of selling heating as a service is actually already operating in district heating schemes such as those we have installed for Flagship Group in East Anglia. Tenants are simply charged for the heat they use. If we are to start making an impact on the climate emergency, we need to shift our mindset to new ideas – although buying water and electricity has been done in this way for years!
We have to end our love affair with high temperature heating and stop simply replacing one condensing boiler with another one as this is what we’ve always done. Heat pumps are not new technology (they were invented in 1945!) but we must start dispelling the myths and changing perceptions on these systems to get them installed right now.