Do you need new radiators when you have a heat pump installed? Here we explain the common scenarios.
- Do you need new radiators with a heat pump?
- Heat Loss Calculations
- Cost of New Radiator Installations
- Choosing the Right Radiators for a Heat Pump
- What About Underfloor Heating?
- Heat Pump Radiators FAQs
- How long does underfloor heating last versus radiators?
- How much larger should radiators be with a heat pump in most cases?
Before having a heat pump installed, one consideration to take on board is whether your existing radiators are suitable.
In many cases, new, larger radiators will be required to enable a heat pump installation.
But why would this be necessary and how can you tell whether or not your home will need new radiators?
Let’s dive in...
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Do you need new radiators with a heat pump?
Since heat pumps work at a lower flow temperature than boilers, they require a larger overall radiator surface area in order to sufficiently heat a home.
Therefore, you may find that you’ll need larger radiators in order for a heat pump to do its job properly.
Whether or not you will need larger radiators will depend on a variety of factors, however, there are ways of determining this with the help of a qualified heating engineer.
It’s also worth mentioning that should you require larger radiators, you may find it more appealing to opt for underfloor heating instead, but we’ll discuss more of that later.
Heat Loss Calculations
Heat loss calculations are used by professionals to determine the size of radiators needed for given spaces.
This will help you figure out whether or not you’ll need larger radiators. You should not attempt this DIY, however, and should leave it to a professional.
The initial calculation required is U Value x Wall Area x Delta T.
Without getting too technical, Delta T is determined by the difference between the ideal temperature of your home and the average lowest geographic regional temperature (i.e., outdoor temperature) in the wintertime.
The U Value relates to insulation. First, another value known as the R-value must be determined.
To give an example, an uninsulated residential wall may have an R-Value of around 4 whereas if this wall was well-insulated, the R-Value would increase to approximately 14.
The U Value is then calculated by 1/R Value. A U Value in relation to a well-insulated wall may end up around 0.07.
Further calculations are needed to ultimately determine the BTU requirement of radiators for a given property.
Watch Our Air Source Heat Pump UK Case Study in the video below:
Air infiltration heat loss plays a role toward the end of the process in ultimately providing the total heat loss.
Again, you’ll need to hire a qualified heating engineer to make these calculations to ensure that you get the right radiators for your home.
Of course, you’d have to hire an engineer to install your heat pump anyway, so you may find it best to hire them for making the calculations and replacing your radiators too (if required).
With a bit of luck, you may, in fact, not need any new radiators, however, in many cases, radiator replacements will be a requirement.
But how much would this add to your bill?
Cost of New Radiator Installations
Depending on the type of radiator you opt for, you’d be looking at spending approximately £200 to £400 per radiator replacement.
This would include both the labour and supply costs.
The total price of having new radiators installed can vary depending on a wide range of factors.
For one, you may only need several radiators replaced, whereas, in properties where their current setup is far from sufficient, all radiators may need replacing.
Beyond that, your bill will also be influenced by the type and quality of the radiators being installed as well as your location.
Your property location will be relevant to the cost of labour and heating engineers charging different rates across the UK.
For example, on the one hand, labour prices tend to be lower in northern England, Scotland and Wales than say southern England.
All in all, you’d be looking at paying the approximate following costs depending on the number of new radiators you’d require:
Number of Radiators Being Replaced | Total Cost |
1-2 | £200 to £800 |
3-4 | £600 to £1,600 |
5-6 | £1,000 to £2,400 |
7-8 | £1,400 to £3,200 |
9-10 | £1,800 to £4,000 |
11-15 | £2,200 to £6,000 |
16-20 | £3,200 to £8,000 |
21+ | £4,200 + |
Choosing the Right Radiators for a Heat Pump
An important consideration to take on board is ensuring that you find the right radiators to go with a heat pump.
Finding the exact radiator models that would best suit your property would depend on a variety of factors including whether you are having a ground source heat pump or air source heat pump installed.
However, in general, relatively large aluminium radiators are a fantastic choice for heat pumps.
This is because aluminium is a highly effective conductor meaning that it can warm up a space much faster than say cast iron or steel radiators.
Aluminium radiators are well-suited to a heat pump instalment.
After all, given the low flow temperature offered by a heat pump, it’s important that as much of this heat is distributed via your property as soon as possible.
When it comes to finding the best radiator models to go with a heat pump for your property, you should consult with your heating engineer.
This way, you can both run through a range of ideas before deciding what radiators should make the final shortlist.
Once this is achieved, you’ll want to weigh up your preferences and priorities, whether in relation to your budget, the BTU of the radiators or their look/design style.
What About Underfloor Heating?
Underfloor heating is a great alternative, not least because it may not cost much more (if at all) than having all your radiators replaced.
While having underfloor heating would be way more disruptive than simply replacing your radiators, you can probably have an electric underfloor heating system installed for around £4,000 to £5,000.
The cost would rise to approximately £10,000 to £11,000 in the case of a water-based system.
It should be noted that the above prices assume that you are having your existing property renovated.
That is because it is significantly cheaper to have underfloor heating added to new build property.
In the case of a new build, you’d be looking at a price tag of £2,000 to £2,500 for an electric system or £5,000 to £6,500 for a water system.
Underfloor heating offers a wide range of benefits including a high level of energy efficiency, longevity, a warm underfoot, and the ability to free up space.
By having all radiators removed and underfloor heating installed, you’ll have plenty more wall space and room surrounding your walls to utilise for other reasons or simply to create a more open look throughout your home.
Lastly, you may be interested in opting for a hybrid system, whereby you use underfloor heating and radiators.
For example, you might choose to have large radiators installed upstairs while having your radiators swapped out for underfloor heating downstairs.
This may be a more viable option in some properties where adding underfloor heating on the second floor is especially difficult or downright impractical.
Heat Pump Radiators FAQs
How long does underfloor heating last versus radiators?
Since underfloor heating may last up to 50 years or even longer, it is clearly a far longer-lasting option than choosing to have your radiators replaced.
While underfloor heating may end up costing longer (though that’s not guaranteed as prices can vary from property to property), it certainly offers more value for money.
If you want a great long-term investment, then you should give serious consideration to opting for underfloor heating over having new radiators installed.
How much larger should radiators be with a heat pump in most cases?
On average, replacement radiators may need to be x2.5 times as large as existing radiators if having a heat pump installed.
However, this will depend on a variety of factors including the current size of your radiators and your heating/hot water needs.
As mentioned earlier, you may not require new radiators at all. It’s really determined on a case-by-case basis.
