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Will A Heat Pump Improve My EPC Rating?

Will a heat pump improve epc rating

Well it depends

Over the last few years there has been a drive by the uk government to reduce our reliance on fossil fuels and reduce CO2 emmision in our homes.

Previous grant funding schemes such as the renewable heat incentive (RHI) for renewable technologies such as heat pumps and biomass boilers and now the newer Boiler Upgrade Scheme (BUS) incentivice homeowner to invest in these technologies by providing financial subsidies.

But with all this being said, will it actually improve the energy rating of a property and lower my energy bills?

Well it depends.

First we need to understand what metric the EPC uses to rate the property.

The metric it uses is the cost to provide heating, hot water and lighting in the home. So the lower the running costs, the better the EPC rating will be.

When you install a Heat Pump you will be changing from whatever fuel source you currently have be it gas, oil, lpg etc to electric.

How Efficient Are Heat Pumps?

 

Heat pumps, and we’re taking about air source heat pumps here, are between 250% to 380% efficient, depending on make and model.

This means for every 1Kw of energy the heat pump uses, it outputs between 2.5 to 3.8 kw of usable energy in the form of heat.

This is extremely efficient, compared to a good condensing gas boiler which is only 90% efficient at best.

However, that’s not the whole story. Unfortunately because of the cost of electricity, it will still cost more to heat and provide hot water to a home with a heat pump than it would with a gas boiler.

So if you’re changing from a gas boiler to a heat pump, it will definately lower your epc rating and increase your energy bills.

Ground source heat pumps are even more efficient at around 400%. It’s only at that level is it a comparible running cost equal to or better than gas. However, ground source heat pumps are significantly more expensive and will be a subject for another article.

Under the governments previous renewable heat incentive scheme, in their guidance document it said:

Although the Domestic RHI scheme is for homes both on and off the gas grid, the latter are usually more expensive to heat and have higher carbon emissions. Those without mains gas have the most potential to save on fuel bills and decrease carbon emissions.

So in their guidance note above, it’s saying in a roundabout way that installing a heat pump may not be the best option for everyone.

The main driver for government is to reduce CO2 emmisions. This a heat pump will definately do.

Why heat pumps are more suitable for newer properties

In the new building regulations which came into force from June 2022, there is a new CO2 emmisions target for each new home and that target can only be met by installing either a heat pump or solar photovoltaics.

But with new homes being super insulated and air tight, the running costs are very low and any cost differentials between using gas and electric for a heat pump are a lot smaller.

However, this is not always the case for a lot of the existing housing stock.

So the main answer to will a heat pump lower my energy bills and improve my epc rating is really dependant on the fuel source you are moving from.

We will look at some examples below. Here we take a deep dive into the EPC software to show you some comparisons using different fuel sources.

Examples and comparisons of moving from different fuel sources to a Heat Pump

Before we look at the examples, there are 2 important terms we need to understand about heat pumps they are:

  • Coeffiency of Performance (COP)
  • Seasonal Performance Factor (SPF)

What is Coeffiency of Performance (COP)?

Coefficient of Performance (COP) is a number that shows how much heat a heat pump can produce for each unit of electricity it uses.

Imagine you have a heat pump in your home that is used to heat the air in the winter. If the heat pump uses 100 units of electricity to produce 300 units of heat, the COP would be 3 (300 heat units / 100 electricity units = 3). This means that for every unit of electricity used, the heat pump is able to produce 3 units of heat. So, the higher the COP, the more efficient the heat pump is.

Seasonal Efficiency Performance (SFP)

Heat Pumps Seasonal Efficiency Performance, or SFP, is a measure of how efficiently a heat pump can heat a home over the course of an entire heating season.

It is typically expressed as a ratio or percentage, with a higher number indicating more efficiency.

The SFP takes into account factors such as the outdoor temperature, the heat pump’s performance at different temperatures, and the amount of time the heat pump runs.

A heat pump with a high SFP will be able to heat a home efficiently even when the outdoor temperature is very low.

For an Air Source Heat Pump a typical SPF is 2.8 and for a Ground Source Heat Pump a typical SPF is 4.0.

As Air Source Heat Pumps are by far the most common, our examples will be using an SPF of 2.8.

Comparison Examples Of Moving From Different Heating Sources

In the following epc ratings and running costs comparisons, we are going to show the epc rating and the running costs moving from the following fuel sources:

  • mains gas boiler to a heat pump
  • oil boiler to a heat pump
  • storage heaters to a heat pump
  • LPG boiler to a heat pump

All the examples, if there is a boiler, will be moving away from a high efficiency condensing boiler.

I should also mention, these are actual comparisons entered into the actual EPC software.

There are many discussions on the internet whether the EPC methodology accurately reflects the impact of heat pumps.

That discussion is for another article. What we are demonstrating here is the actual output from the EPC whether we agree with it or not. 

I will be using 2 properties of different thermal values. The only changes that will be made to the properties in the examples below will be the heating system.

Modern property built 2005

Property 1 - Detached House Built 2005

This property has good levels of insulation in the walls, floors, roofs.

1900 detached house

Property 2 - Detached House Built 1900

This property has 250mm insulation in the loft but no other forms of insulation in the floors and walls.

Mains gas to a heat pump

Detached House Built 2005

Fuel Source
From Gas Boiler
To Heat Pump
EPC rating
C 75
C 71
kwh
13,440
15,298
Running Cost
£1,486
£2,099
41% Increase

Detached House Built 1900

Fuel Source
From Gas Boiler
To Heat Pump
EPC rating
E 52
E 42
kwh
22,366
29,270
Running Cost
£2,474
£4,015
62% Increase

Oil to a heat pump

Detached House Built 2005

Fuel Source
From Oil Boiler
To Heat Pump
EPC rating
D 64
C 71
kwh
13,440
15,298
Running Cost
£1,314
£2,099
60% Increase

Detached House Built 1900

Fuel Source
From Oil Boiler
To Heat Pump
EPC rating
F 31
E 42
kwh
22,366
29,270
Running Cost
£2,187
£4,015
84% Increase

Storage heaters to heat pump

Detached House Built 2005

Fuel Source
From Storage Heaters
To Heat Pump
EPC rating
D 64
C 71
kwh
14,739
15,298
Running Cost
£1,441
£2,099
41% Increase

Detached House Built 1900

Fuel Source
From Storage Heaters
To Heat Pump
EPC rating
F 35
E 42
kwh
25,839
29,270
Running Cost
£5,943
£4,015
-32% Decrease

LPG boiler to a heat pump

Detached House Built 2005

Fuel Source
From LPG Boiler
To Heat Pump
EPC rating
F 32
C 71
kwh
13,440
15,298
Running Cost
£3,566
£2,099
-41% Decrease

Detached House Built 1900

Fuel Source
From LPG Boiler
To Heat Pump
EPC rating
F 22
E 42
kwh
22,366
29,270
Running Cost
£5,934
£4,015
-32% Decrease

In the spreadsheets above you will notice that the heat demand in kwh for the property increases if a heat pump is installed.

This is due to the fact that a heat pump runs at a lower temperature and therefore has to be running for a longer period of time.

A similar situation occurs if the property uses storage heaters.

Source Of Fuel Costs  

The costs of the varying types of fuels have been calculated by Nottingham Energy Partnership, who compare the cost of all fuels types on a monthly basis.

Stop guessing EPC rating

Summary

Customers are often disappointed when they’ve spent a lot of money on an air source heat pump only to find that their EPC rating has dropped.

This is because the EPC is measuring the cost of heating the home as the main rating factor, not the CO2 emissions.

So in general, if you are moving away from gas or oil to a heat pump, your EPC rating will be lower.

If you are moving away from storage heaters or lpg to a heat pump, then your epc rating will be higher.

5 Comments

  1. Rickie Dickson

    Hi Paul
    Thanks for your comments.
    It would be an interesting if you could show as a comparision how having a heat pump has worked for you.

    Reply
  2. MR ALAN LEE

    What if you are moving from a non-condensing, non-combi gas boiler to a heat pump or a modulating , weather compensating electie barewire boiler?

    Reply
  3. Tim Tucker

    If he house, , built in 2008, has solar PV and battery back up, then the advantage swings to air source heat pumps surely?

    Reply
    • Rickie Dickson

      Yes Tim, I would agree you.

      Reply
  4. John Tyne

    This article is interesting, but there are some elements that do not make sense to me, and I am dumbfounded by the statement:

    “Customers are often disappointed when they’ve spent a lot of money on an air source heat pump only to find that their EPC rating has dropped. This is because the EPC is measuring the cost of heating the home as the main rating factor, not the CO2 emissions.”.

    In the example for the well insulated 2005 detached house on a gas boiler:
    – the EPC rating is C 75, 13,440kwh, £1,486pa running cost.

    In the example for the well insulated 2005 detached house on storage heaters:
    – the EPC rating is D 64, 14,739kwh, £1,441pa running cost.

    In conclusion:
    If the owners of the detached house moved from a gas boiler to storage heating, even though the running cost is comparable and they are not burning gas in their home, their EPC rating would drop down to a D. This is ludicrous.

    Many energy providers such as Octopus, Eon, etc provide renewable electricity (although I’m sure it is not exactly 100% renewable, but they say it is), and so this has got to be way better than being on gas. Despite this, the owners would get punished for it.

    This article is telling readers to stay on gas, burn fossil fuels and create more C02, and be rewarded with a higher EPC rating.

    Reply

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