You thought this was going to be one of those Heat Pump bashing articles didn’t you? Well if that is what you clicked for, you might as well click away now. If you are interested in honest, unbiased, facts then please do read on.
First, a little fact-checking is in order.
Claim: Heat pumps are more efficient than gas boilers – True
Heat pumps ARE more efficient. We measure efficiency with what we call COP, Coefficient of Performance. An electric heater has a COP of 1, which means 1 unit of power in, 1 Unit of heat out. Modern gas boilers have a COP around 0.9, and Heat Pumps being anywhere between 2 and 5. You may see reference to SCOP which is an average COP taking into account seasonal variations in outdoor temperature, SCOP is what you need to use to make comparisons.
Claim: Heat pumps will save you money on your heating bills – Misleading
The fact is that this will vary from installation to installation so it is not possible to categorically state this. It also depends on the gas and electricity tariffs that you are on. Taking the current Octopus Flexible Plus Tariff with electricity at 29.94p and gas at 7.51p, for a heat pump to be cheaper to run you would need the heat pump to achieve an SCOP of around 3.6 to break even on running costs. This is possible and well installed systems can exceed this, though it can take a long time to pay back the higher install costs, which should also be taken into account.
Claim: Heat pumps do not work in very cold weather – False
Heat pumps work down to about -21c, some even colder. With Air Source, the colder the outside air, the less efficient they are, hence the need for SCOP to get an average for baseline comparison.
Claim: Heat pumps need a very well insulated house – False
There is nothing to stop you from putting an oversized heat pump in to heat an uninsulated house. It will be expensive to run, but it will keep you warm. When bringing insulation into the argument it is important to note that any insulation upgrades to make a Heat Pump work more efficiently would have exactly the same effect on a gas boiler, if you make your property more thermally efficient it costs you less to heat.
So now we have got that out of the way, let’s get to the lies and the damned lies coming from both sides of the debate. Earlier this afternoon Greenpeace UK tweeted (is it x’d now?)
“BREAKING: New research has shown HEAT PUMPS are TWICE as effective at heating homes than fossil fuel – meaning CHEAPER ENERGY BILLS.” showing without a shadow of a doubt that they either have not got a clue what they are talking about, OR, they are just plain liars. Firstly, if you are promoting heat pumps, why talk the technology down? An SCOP of 3 is easily achievable (that’s over 3x more efficient than a Gas Boiler. Secondly, if heat pumps are going to mean cheaper bills at twice the efficiency you would need an electricity cost of around 16p per unit. We can only dream of 16p per unit!
On the flip side, A well-known commentator posted: “I spoke to a heat pump expert today, turns out,they don’t work really well in cold temperatures. Turns out that below zero, they have a big problem.”
Define “cold”. It doesn’t get down as low as -21c in the UK very often, if at all in most parts. Any good heating engineer should design a system to work at the coldest possible temperatures, so if a heat pump does not keep a property warm, it is totally on the installer. Posting something along the lines of “they are expensive to run in really cold weather” would have been a fair comment though using average running costs is more accurate as the efficiency of an air source heat pump is a variable.
What SHOULD be happening, is that installers make sure that whatever they install works as efficiently as it can, be that a heat pump or a gas boiler. The installer should be calculating or measuring the heat loss of a property and comparing the running costs of any proposed system to the existing one so that homeowners go into it with eyes open.
THERE IS NO EXCUSE FOR LEAVING A CUSTOMER COLD BECAUSE YOU DID NOT CORRECTLY DESIGN THEIR SYSTEM! Likewise, there is no excuse for a customer getting an unexpectedly high electricity bill because you did not explain the running costs.
The problem is, we are seeing yesterday’s combi slingers move onto heat pumps chasing government grants. Many smaller installation companies have’t got the time or the inclination to undertake the box-ticking exercises demanded by MCS, preferring to concentrate on offering their clients quality workmanship. While there are some VERY good heat pump installers, for now they are few and far between. This is probably the source of the “heat pumps don’t work in cold weather” line. If we look at the difference between some of the big boys like Boxt, vs small one man bands in the boiler market, most of those one man bands would not fit a 37kw boiler when a 12kw is more appropriate and the heat pump market is no different.
Is the push to heat pumps really about decarbonising the grid? As things stand, clearly NOT. If the main aim was to decarbonise the grid, Air to Air heat pumps would also qualify for the grants. They are cheaper and faster to install. They also benefit from providing cooling in summer, however, the green lobbyist does not see this as a benefit because they would rather we all sat shivering or sweating in caves than use energy. Perhaps that is a slight exaggeration, but it certainly is how they come across sometimes. Air to air is a far easier sell than air to water in most cases because of installation cost. If the average air to water heat pump installation is £10-£15k, the average air to air installation is £3-£5k. Throw in the benefit of cooling in summer as added value and people would be far more interested, especially with grant assistance. After all, if the climate catastrophe rhetoric is to be believed, cooling is going to be essential.
What would be really good, is if people who know sod all about the subject stopped making silly claims that they do not understand. Environmental groups, commentators, and politicians are ALL guilty of this. What would also be good, is scrapping MCS altogether and bringing in a competent person scheme that is more concerned with the actual work rather than the paperwork. If decarbonising the grid is the goal, it needs to be led by the engineers, not the lobbyist. Bringing people with you is easy if you offer them a direct benefit, lying to them about efficiency being cheaper when you ignore fuel costs will have the opposite effect.
So the gauntlet is well and truly laid down to both sides of the debate. Will you continue to lie and find statistics that support your case ignoring all others, or can we start having grown-up conversations about the practicalities of various technologies and even if we have to scrap gas at all? If decarbonising the grid is the goal, it is the competent engineers who install the technology who know how to get this done, and they are the one group not being asked how we get this done. One thing is for sure, we cannot push people into poverty over a pipe dream built on lies, damned lies, and statistics.