Home » Far Infrared Heating. It’s heating, Jim, but not as we know it! (but you may need more power, Scotty)

Far Infrared Heating. It’s heating, Jim, but not as we know it! (but you may need more power, Scotty)

ACC HAUS founder, Jeff Rhys-Jones, shares his ‘experiences’ in the conversion of his 1920s home from gas to Far Infrared heating…

(**October 2018 Update**: we have added a Herschel Summit 2600 to our FIR ‘armoury’ in order to better fight the heat loss ‘battle’ in our main open plan living space! Full write up here)

It’s been a year since I completed the renovation work on our 1920s era home, part of which was a rather bold move to ditch the traditional gas central heating, and instead switch to a completely different type of heating, Far Infrared (FIR). It’s certainly been an interesting (in both a good and bad way!) project and so I thought I would share our experiences on this blog to help any other ‘conFIRts’.

Quite a few of the challenges experienced probably require their own blog but I thought I would kick things off with a err – ‘brief’ – summary of the pros and cons for those interested.

What is Far Infrared (FIR) heating?

Far Infrared comes in many forms these days – wall & ceiling panels, underfloor heating, and even domestic hot water (DHW) and ‘wet’ central heating systems. Whatever the form, they all use the same principle of generating FIR by passing electric current through a panel containing layers of carbon graphite polyimide, copper, nickel & nano silver to around 100c at which point long wave infra read / FIR is emitted. Unlike a traditional electric room heater, FIR is only absorbed by ‘matter’ and not air, so it does not rely on convection for heat transfer. The theory goes that as you are not heating air, but matter, far less energy is required to heat the same space than traditional electric heaters.

Is FIR really far better?

I can confirm that it’s true, FIR panels *do* emit a more natural heat sensation, the analogy used by many companies who sell FIR panels, is that of the sensation of feeling the sun on your face, on a cold winter morning, is a claim I can verify – though I’m afraid you can change back out of those Speedos – you won’t get a tan!

There are quite a few listed health benefits, mainly because without heat convection, there is less house dust in circulation, so people with asthmatic conditions, or simply just don’t like the drying out / ‘Bombay duck’ feeling of traditional central heating will find living in a FIR home far more comfortable. Our old central heating system somehow used to suck the life out of me like a Dementor from Harry Potter which would lead to constant ‘window open, window shut’ arguments with the wife every night.

We no longer have a gas boiler or any radiators, so because of that – there’s no requirement for gas boiler repairs, gas checks, pumps, valves, pipes, leaks and the pain of annual radiator ‘weeing’ as the wife used to call it. Being electric and with no moving parts, a FIR solution is essentially ‘solid state’ and therefore requires pretty much no servicing and panels can simply be swapped out by a home owner if they do break. So it’s certainly a far more resilient & ‘sold state’ type of solution. So there are certainly savings made on not having to service it.

Where To Put Them?

(above) 400w FIR panel on ceiling of upstairs hall. Always try to match panel ‘shapes’ to match the space you intend to heat – so in this case, a long thin panel was a better choice than a square one.

The best place to fix FIR panels is on the ceiling, so this means a huge amount of wall space in your house can be reclaimed that was previously taken by ugly looking radiators. FIR panels are an interior decorators dream. Perhaps you don’t want to put anything on the wall at all – and you can feel really good about having a pure white space to look at. Some do!


The images on this website of glass FIR panels placed on ceilings are not Herschel, but by another FIR panel vendor. Herschel do not recommend ceiling mounting with glass FIR panels for any of their products. Herschel glass FIR panels should only be wall mounted.

Please visit the Herschel website for more information on their ‘Inspire’ range of glass FIR products.

Being electric, together with smart home technology, you can create some highly customised, and efficient heating regimes. Heat rooms based on individual preferences, perhaps automatically turn down if movement is not detected for a number of days. It’s true that the £/KwH is more for electricity than gas, but with a wet central heating solution, you can’t simply ‘move’ a working radiator from one room to another. With FIR you can heat three rooms in rotation, using a fixed kWH budget – so a bit like getting a heater, heating a room for a bit, physically moving it to the next, and so on, until all rooms are up to temp. Once rooms hit the desired temp, they drop out of the loop, and thus ‘shortening’ it, so that the remaining rooms get more heat, until they in turn drop out, until all rooms come out of the loop and heating is off. So it’s a loop rotation system that ‘spread’ heat around the house. We have created a powerful Loxone program to do just this – we call it SLAM or Sequential Loop Active Membership.

Read our Loxone setup guide


Above: A basic demo of our Loxone SLAM program. Naturally SLAM works for any devices you want to run in a dynamically changing sequence…

FIR heating is quite responsive, unlike underfloor heating which can take quite a while to get going, you can ‘boost’ a FIR room back up to comfort temperature in a very short time. Likewise, if a room was ever to get too warm with FIR, the panels can simply be turned off.

The panels are very nearly 100% efficient. With no heat loss though boiler, pipes and other heating paraphernalia such as pumps.  It takes 600 watts to run a 600w FIR panel, and all of this energy is transferred to the room – so there is virtually no loss at all aside from minimal resistance in electric copper cabling.

Finally, they can be powered by the sun. It’s going to be a while until a household can viably generate its own gas, but you can use solar to  generate your own electricity. On a sunny winters day, if you have a large sized PV system on the roof (we have a 4KW system), you’ll likely not have to pay anything for your heating at all.

FIR – The Considerations

Any technology which is powered by electricity is going to be more expensive to run on paper, than gas, simply because the cost / KwH of electricity is far higher than using gas. So the key factors to a successful FIR deployment are as follows:

Insulation, insulation and insulation!

As with any heating solution, the better insulated your house, then the better it will retain its heat, and therefore the less time it will need to be on. If your house has poor insulation then the W/meter cubed required to heat your home will be higher, and therefore so will your electricity bill. Just with anything electric, it will be considerably higher! So work our your w/ meter cubed first, that will help you estimate your worst case scenario electricity bills.

Panel type and placement

This is rather crucial. Panels should be placed as central to a room as possible, and remember that FIR cannot pass around corners, so any strange shaped rooms would be better suited to multiple smaller panels, rather than a large central one.

At ACC HAUS we have partnered with and recommend panels from Herschel Infrared, who offer a great range of FIR panels for all budgets. The crucial factor with Herschel panels (for the UK market specifically) is that they are supplied with UK rated elements, and not EU rated. Calm down, this is nothing about Brexit (after all our Smart Home system vendor is Loxone – from Austria!) but actually about voltage, and how the panels perform. We mention this a few paragraphs down, but as Herchel supply panels with heating elements specifically designed to run at 240V, the output wattage exactly matches the specified wattage. If you were to buy a FIR panel with an EU / 230V element, your 600W panel would actually run at something like 640W. You may think more wattage = better, but actually it’s quite the opposite.

So this is why if you are in the UK and considering buying a FIR panel, you should make sure it’s Herschel.

Thermostats / temperature sensors

They more you have the more you can manage and optimise. Because FIR heats matter and not air (which is what thermostats measure) you would typical set a thermostat a few degrees lower for FIR than for traditional central heating. So 19.5c rather than 21.5c. Using smart home management systems such as the Loxone system which we use and recommend, you can even feed multiple temperature sensors into a room control system, so take readings from different parts of a room and from this calculate an average.

Smart Home Management Plans

This is certainly a topic in its own right, but basically, if you are thinking about FIR you really should also consider deploying it with full smart home integration, monitoring and reporting in order to control running costs. For our project we used the powerfully and highly functional Loxone Smart Home solution. ACC are a fully qualified / certified Loxone Silver partner – so please contact us about any Loxone requirements!

Secondary / Alternative heat source

(above) A RAIS 2:1 double sided integrated stove in use as a supplementary / alternative heat source)

To take the ‘heat’ out of deep winter bills, I would recommend building an additional high power heat source that uses and alternative energy source from electricity, a wood burning stove with passive heat circulation to other rooms in the house is a great choice – and something we installed. It means in a power cut, we don’t freeze!

Wiring & fixing points

I would caution anyone trying to retrofit FIR room by room, rather than part of a full refurb. If you have one room which is not on your central heating, then fine, but doing the whole house – that’s a big job. If you are refurbishing anyway, as we were – then this is the time to think about it. Make sure you isolate your panels to their own ‘rings’ and carefully calculate the max potential load on each ring.

Temperature Sensor Placement

This needs to be carefully thought out. If your sensors are too close to your panels, the entire room will not get up to heat, but conversely, placing them too far from the panels, you may find your panels are on more than they need to be. Thankfully Loxone make a wireless light switch with built in temperature and humidity sensor, so this gives you the ability to move it around to get the best placement.


A FIR BIGGIE! If you are buying FIR panels, you need to check with the panel vendor that the heating elements in the panels are rated to run at your local voltage, in, in the UK, this is 240v. We were unlucky enough to ‘learn’ this important fact only after we found our now recommended FIR panel vendor of Herschel Infrared.

We made the mistake of purchasing FIR panels with elements rated for 230v, because pretty much like everything else in the house runs fine. This is totally legal, however, for ceiling panels in particular – can cause major problems, because UK voltage is 240v – all of our FIR panels were running over wattage. Yes, they will give out more heat – which you might think is good – but not so. To prevent them overheating, FIR panels have a built in overheat cut off safety feature, and up on the ceiling where it’s warmest, a panel that is supposed to run at 230v and 600w, on 240v will likely run at around 640w. Doesn’t sound like a lot, but this WILL cause the panels to run hotter, overheat, and constantly switch off (you will hear constant clicking sounds as this occurs). This is in no way dangerous, (quite the contrary it proves the safety feature works), it’s just that with all the clicking off, cooling down, and then heating up etc, this completely disrupts the generation of FIR and therefore means you won’t be getting uniform output.

This was exactly the case for us, strangely, more so in some rooms than others. FIR panels were never getting a long enough ‘burn’ because they were constantly clicking off and on. But we had purchased and fitted all our FIR panels (all 28 of them!) and there was nothing technically ‘wrong’ with them. Some lateral thinking was required!

The (rather ingenious I might add!) solution was – rather than return and replace all the panels, and likely have to re-do all the mounting points (lot of work) – was to purchase in a VO or ‘Voltage Optimiser’ which enabled us to down step the voltage in the house from 240v to 226.5v – so very nearly 230v. This was only possible because we have all the panels on their own dedicated power rings, so we simply moved the FIR rings over to the VO and the problem was solved. It’s not really what at VO is supposed to do, but it really saved our bacon!

The take away from all of this, is hopefully on reading this blog you will not fall into this same trap as us, and you will make sure your FIR panels are 240v rated elements – which if you buy from Herschel Infraredwill be the case.

EPC Rating

Another biggie. If you are doing a retro fit, then prepare for your EPC rating to drop like a stone. You will be subjected to a type of EPC check called an ‘rdSAP’ (residential SAP) type of assessment. This type of EPC check has many assumptions, and also, there is no ‘category’ for your FIR panels, so the rdSAP assessor will simply put them in as ‘Electric Panel Heaters’ which will result in an awful rating.

To get around this, you need to embark on something called ‘Full SAP’ – something usually done for new builds only. However – thanks to a brainwave by Mark Hunt at MH Energy Consultants – if you change your primary heat source (as we did) plus you have full architect’s drawings, so floor plans, elevations and importantly cross sections. So this is a much more accurate figure can be calculated by a Full SAP assessor. The difference is huge. After rdSAP – for our renovated home, they came back with a rating of E, and very nearly nearly F (awful). Full SAP, the house was upgraded all the way to C. After the rating was awarded, ominously the powers that be (presumably surprised that an electric powered house could obtain a C rating) demanded a full EPC audit. That came back… with 100% accuracy – so C it was – and I have a strong suspicion that we own the only 100% FIR heated 1920s era property with a C rating in the UK – and who knows, perhaps Europe too?! With feed in tariffs (FITs) kicking in from D and better, you can see getting the Full SAP was important. Even without FITs – your EPC figure will no doubt be printed on the estate agents details about your home if you ever decided to sell, so a bad rating might make the property less attractive. New regulations coming in to force in 2018 could also prove extremely troublesome (you will not be able to let the property for rent!) if your EPC ratings are below E.

Is FIR cheaper than gas central heating?

For us, I’m pretty sure, no. At the moment, gas is seriously cheap compared to electrics, and boilers are getting more and more efficient all the time. We were one of the last households to scrape in with a FIT before the end of the year (last few days of 2015) We will be generating and earning much better yields from our 4Kw array through the summer, and we’ve estimated this will offset over the additional amount spent during the winter. There is still quite a bit of optimising to do in the house, plus some internal & external insulation that can be added to older external walls, plus we will have a much larger log store to enable us to buy wood in bigger bulk during the summer when it’s cheaper.

So next year I’m hoping we will be running a much tighter (and warmer) ship. Realistically though I think we will be paying pretty much the same.



Energy Usage & PV With FIR

Take a look at some of the following charts.

Firstly, lets look at the total FIR use for the house, which is approx 100sq meters downstairs, and the same upstairs – so we need to heat approx 200sq meters:

So – this time of year (Early April), outside temperatures are ranging from 5c at night to a high of 14 day time. The house needs from 15kWh to 33kWh to heat it.

Next lets take a look at the power generated by the PV system over the same period – which is 4KW:

You can see that clearly, the 10th and the 12th of April were quite sunny days. This time of year, due to the angle of the sun, you’re not going to get the full power out of your PV array, but 17.5kWh is not bad for April.

The next chart shows the amount of energy used by the FIR system, whilst the PV was working. It’s not simply a case of subtracting PV from FIR, because these are per day figures, and it’s possible that some PV power was generated when FIR panels were off. But in any case, it gives you a nice indication of how much FIR power was being used after the PV had been taken off:

So aside the 7th, we are around the 20kWh per day mark at this time of year. This still make some people wince, however remember that in addition to the PV energy we are using, we are at the same time getting a good generation tariff too – and this more or less than covers the cost of what’s left to pay. Finally in the main summer months when FIR is not needed at all, we will also be exporting power into the grid so we’ll get a little extra for that too.

So…. Is FIR for you?

As mentioned above like with most things in life there are benefits and considerations.

The main takeaway point is that a FIR solution is not something that should be done on a whim and should be properly planned, and done as part of a major house refurb as there is quite a bit of wiring to do. There are also quite a few ‘gotchas’ such as panel transformer voltage issues and placement so it’s definitely a project which has the potential to go horribly wrong.

It should also be done in combination with Solar generation and perhaps wind too. Yes it’s likely that in the coldest parts of the year, there is not going to be much sun to power your FIR, but in the Autumn & Spring you will find that plenty of days (like this week!) are sunny but chilly. So your heating for free during the day, good home insulation will keep much of that day time warmth in so you’ll just be needing room by room top ups throughout the night. Today is a very sunny but chilly day, and I can see from the house computer that we’re not using anything from the grid, the house is nicely warm, and there is not a leaky valve or noisy pump in use. Mission accomplished!

Final Word

Quite often in life, the cheapest isn’t always the best. Lifestyle is important. Going FIR for us was less about creating the cheapest possible heating solution, (for that we might have decided to go underfloor heating which I have a passionate hatred of) but more about creating the best quality of heat. Yes that’s right – heat has quality! I just really like the type of heat these FIR panels give out, and the simplicity and room segment control that FIR panels give you.

As the developed world tries to wean itself off fossil fuels, I do feel a little satisfaction that my home is not (directly anyway) heated by them. As mentioned above, on some days, it entirely heats itself for nothing.

The future of heating your home is electric – in my opinion, that’s a cold certainty.

The big question is how little can you get away with using, and are you able to generate and perhaps store, any of it yourself.


  1. Roger Baker says:

    Very interesting article, and informative. Clearly, if you want to retrofit, then you really need to do the sums. A dedicated wiring circuit can be intrusive to install and expensive. The fact there is a ‘conflict of interest’ relating to the voltage rating of the product and the UK rating of a domestic circuit, is important to consider and resolve. As I have an ‘ancient’ warm air C/H system, I have been looking at skirting heating systems, which appear not to be intrusive, unlike traditional panel radiators. Yes, I still require a gas boiler, but these are highly efficient these days, and as the author points out, gas in much cheaper than electricity. And when the ‘lights go out’ (I’m a pessimist) neither system will work anyway!

    • Hi Roger, and thanks for your kind words! Retrofit FIR is certainly a challenge, but maybe you are on to something with regards to the skirting heating system – what about sticking a ring behind coving and then running a small amount of conduit to the panel? Check regs but this would put cables (properly protected etc) within a 125mm ‘safe zone’. So you could run FIR cables around the top of the walls. From what I have learnt looking at the installation cost & work required should be a 2ndary consideration to estimating the running costs. There is no point even considering FIR if you live in a large poorly insulated house – unless you don’t mind big bills. So I would always recommend looking at the building heat loss characteristics FIRST and then from this find a suitable technology to match. Gas is currently the cheapest so you can afford to lose your heat and keep replacing it – and still be cheaper that a FIR solution. Another idea is to consider a system like ESPs Heliotherm ASHP (same company that make the amazing EcoCent system we mention on this site). Paired with special rads, this system will chuck out 4 X the KWs than you put in, even down to -7c. And being an ASHP – these same rads can provide cooling in the summer. As Gas is 3 x the price of electricity, with a 400% efficient system – that, in my view is a game changer. I am actually considering one of these systems for my existing FIR converted property – not to replace, more to use in conjunction and for demos. Personally, I think a FIR / small sized ASHP combo might be a winner – as FIR is much easier to retro fit on the 1st floor as you can drop cables down from the loft….. so using FIR upstairs means you only have to get rads for downstairs, and a much smaller, cheaper ASHP solution. The only snag to this idea is that as a hybrid / mixed system you would not get any subsidy than if you ran your entire home on it….Watch this space!Jeff

  2. Chris says:


    This is a fantastic analysis and thank you for sharing. So I’m in the States and considering doing the same on a 4,000 sq. foot home (although part of that is a rentable apartment (roughly 1000 sq. ft).

    My question is this – it is a new build with pretty much full day sun to a solar array. I want to heat it via:

    1) The primary infrared ceiling panels which I would oversize to each room (that seems to be a common recommendation)
    2) Building will be done with SIPs and hyperinsulated. R38 walls, R49 Ceilings.
    3) Wood burning stove in main kitchen/living/dining area
    4) Passive solar will also play a role but true solar doesn’t kick in till about 10:30am – 5/8pm.

    My question is with the above in mind what would your recommendation be for a solar array. The house is big at 4k sq. feet, but what would be a good recommendation for solar array to truly offset.
    I am looking at the 6-8kw solar array (probably max of the roof I have that is South is 8kw).


    • Hi Chris, thanks for your kind comments about the blog!

      First of all can I say how envious I am that you are using SIPs for walls and ceilings – as mentioned in the blog, you need to conserve as much heat as possible to ensure that your FIR panels are burning away for as little as possible.

      Sizing the solar array is a bit of a tricky question, as your primary size requirement is to get it to offset FIR usage.

      I’m not familiar with the US solar market – are there an subsidies given to those generating solar? In the UK we have generation and feed in tarrifs – so the income from these ‘offset’ a little against FIR use. So that can be taken in to the equation.

      The main ‘offset’ is that you want to use energy from the roof to actually run as much of (or all) of your FIR requirement. To do this we therefore need to work out what will be your average ‘live’ FIR use – so not the total KW usage over 24 hours, but the max load at any one time in your solar generation window – so from 10am to 6pm say. Estimating FIR usage is a critical part I think of implementation, and any decent FIR panel vendor should be able to provide you with all the calcs based on your unique property situation. Your geographic position / winter climate, aspect (and number of windows facing the sun), insulation materials, room size (including height) – heating regimes (for instance, 19c in hallways, 20c in bedrooms, 21 in living spaces etc). I think only when you have all this data, can you work out what your typical FIR load is going to be during the cold season.

      FIR heating is notoriously difficult to control via thermostats as thermostats monitor air temp, which FIR panels do not heat, so as also mentioned on the blog, position of stats is important. They may require adjustment, or if it’s possible , use multiple stats in a room and take an average and use this average to control your FIRs.

      We ended up basically giving up on precise control, and instead used our ‘SLAM’ system to sequence panels around and set the room temps higher, so the sequence is basically always on, unless there is serious cold and then panels over ride and come on independently. Using SLAM our FIR usage will never be more than 1/3 of the total KW output of all panels put together. We have 25KW of FIR panels here for a 200m2 house, and a such the maximum draw never exceeds 4KW when SLAM is in operation. Typically it is nearer 2KW because some SLAM strings are not active. This is extremely temperature dependant for us as we have a old style house partially built with solid wall (no insulation at all!). So with a SIPs house, I would expect KW usage to be far far lower.

      So not really a definitive answer I’m afraid – but hopefully useful?

      You didn’t mention ventilation, I’m sure as you are using SIPs you will be wanting high levels of air tightness, so you will be looking to use some sort of heat recovery system?

      For your wood burning stove, I would recommend getting one that can take an externally fed air source for this if it’s possible – otherwise you will get air pressure issues with tightly sealed houses. So our wood burner gets it’s air supply from the outside which runs under the floor via a 200mm pipe and then rises up and connects to the underside of the stove. Try to avoid systems that ‘pump’ air in via smaller 22m pipes as these will not work if you ever suffer a power failure… with a FIR powered house at night – that stove will be much appreciated – good call putting that in! Our stove was also designed to feed heat to part of the upstairs – which is super simple (basically an heat exchanged air pipe) but quiet effective!

      Kind regards,


  3. Stuart Mealing says:

    Thanks for an interesting article. I’ve been looking at FIR for an old detached stone sail loft at our new property which my partner and I will be using as artists’ studios but can find no-one who has such a system installed to ask about them. There’s plenty on the internet but usually from someone with an interest in promoting FIR and the electricians I’ve spoken to tend to hold opinions but without first hand experience. Unfortunately electricity is our only practical choice (and being in a conservation area rules out solar or wind generation) but FIR looks as though it might work for us. We expect to be be using the space (three rooms, each about 11×17 feet – two studios with high ceilings and one low room for storage/preparation) intermittently and just want to keep ourselves warm when working and keep the structure of the building dry and sound. A local company has recommended two heaters totalling around 2kw in each studio and 1kw for the storage area with thermostats in each space. We don’t need the spaces to be cosy but want the heating to be fairly immediate. Any thoughts you have would be welcome. Thanks again.

    • Hi Stuart, thanks very much for your feedback, and welcome to our ‘Haus’!

      This is mentioned in a number of blogs / articles we have on FIR around our site, but I would recommend the following:

      1) Get a good FIR panel provider. We recommend Herschel, and not just because they are better panels and rated for the UK, but also because they offer pre-sales service that is vital to FIR projects – so will help you with 2)

      2) You need to approach a FIR solution somewhat a little more scientifically than say gas CH. A good panel vendor like Herschel will do all of the maths for you, select the right sized panels, place them properly, place thermostats and then calculate average heating bills, based on your working habits. You really want to know what sort of heating estimate you are going to be expecting before you start. Draw up a plan, give them as much info about the space as possible (even down to estimating the thickness of walls, which walls are south facing, rooms with external walls etc – as much as you can. These details really matter.

      3) Control – of course we are a smart building specialists (and in particular with FIR control) so naturally we would recommend controlling your FIRs using something like our Loxone solution, and if possible adding on extra ‘smarts’ too. Doing this will enable you to keep on top of usage, enable you to do clever things like activate panels only on motion, and also ‘tune’ it better. Don’t worry about wall thickness and the wireless controllers, we have ways of solving that problem (we have a case study of a circa 1900s house in France with thick internal sold stone walls).

      Fitting a FIR system is not difficult, any competent electrician should be able to do do this. There’s a blog on our site (see related column to the right) about how a small flat is done. Might be useful. It’s simply a case of giving them a plan of where to place the panels and telling him what wattage they are.

      High ceilings in particular are ideal for FIR – heat is not ‘lost’ through air or relies on convection. This is why you will see FIR used quite a lot in warehouses, mounted on the ceiling so the heat literally ‘beams’ down.

      If your rooms are rectangular and no odd nooks (that FIR can not get around) – 11 x 17ft is 187 square and therefore around 17sq meters. But then you have building fabric to take into account. Total wattage of FIR per room is likely to be around the 750W size, however, if you want to direct heat better over working area, it might be better to split this into 2 X 550W – suspect you will need to over rate due to the solid walls. But I would defer to Herschel on this!

      This is why it’s important to supply a company like Herschel with plans so everything can be worked out – you want to be looking at the the cost to implement and then also the cost to run over the heating year too. My suspicion is that a ‘traditional’ electric heater system would be cheaper to implement but will be far more expensive to run over the years as they use more juice. They will also be far more likely to break down, with exposed elements…. we have nearly 30 FIR panels in our own properly, we have not had a single fault on any panel yet. Zero maintenance cost over four years!

      If you would like – I can get in touch with someone @ Herschel for you?

      Kind regards,


        • Thanks for the comment Hugh. I guess this does depend on the size of the panel and also the make of the panel.

          For instance, the article you reference states that the service of panels gets to around 80c – this is on the low side, but might just be the type of panel that was tested. They do say later in the article “If you have higher ceilings, please give us a ring and we can discuss appropriate models to use in this instance.” So yes I would always check with the FIR vendor first, room plan, ceiling height etc and they will recommend the best panel make up. It might end up being a mix of ceiling and wall panels depending on the design of the room.

          Certainly there is no one side fits all solution…. this is why working with a reputable FIR vendor, who will work with you to get an optimum setup, and then also give you running costs – is so important.

          Kind regards,


  4. Ken Windsor says:

    We’re renovating an old chapel approx. 29’x14.5′, 9inch solid brick walls, large single-glazed windows and a max ceiling height of 14.5′. We’ve considered electric panel /convection but thought that the high ceiling would rule it out. FIR seems as though it might suit – approx. 4.5 kw being the estimated need for the space. There is no gas supply and oil is out of the question. We’d prefer to install FIR panels at radiator height to avoid running electric conduit up the walls but I’m very unclear about how FIR would perform; in effect the panels would aim into around a third of the floor area, most of which would be unfurnished as the room will be used for music teaching most of the time during the day. Also thoroughly confused about FIR’s ability to keep the room warm overnight. Presumably the wooden floor (oak planks on battens with 250mm insulation between) would warm up??
    Grateful for your views and advice on whether I’m going in the right direction by thinking FIR is the correct choice.

    • Hi Ken, thanks for getting in touch. I have had a good think and suspect that you may have rather underestimated the KW requirement due to the physical characteristics of the building. Having part of my own property being solid wall, I am not sure if FIR is going to be a good match either. I have had a talk with Herschel about this and they have some ideas which I think might be of interest to you. I will send you their contact details by mail along with a request for a little more information about your building. Kind regards, Jeff

  5. Bryan Poole says:

    It was/is great to read a blog on this subject from someone who has ‘done it’ – thank you. I will shortly be beginning a ‘new -build’ (preparing for retirement!!) and trying to decide on what ‘heating’ I will need (the house will have high insulation levels). I had/have been thinking about ‘combination style’ heating – Infrared Panels for occasional use rooms e.g. Bathroom; Bedroom etc supported by Solar Panels and Underfloor heating for open-plan living area (either via Gas or Air Sourced Heat Pump). Much of the information that I’ve read has, understandably, come from companies/people involved in ‘selling’ their product and it has proved much more difficult to read a ‘user’s story’ – like yours who are likely to be more objective. You indicate in your blog a ‘dis-taste’ for underfloor heating – I wonder if you were able to expand on that a little? For example is your distaste based on personal experience; or the over-selling of underfloor heating. I’d be very grateful if you could expand on your reasoning which might be helpful in my final decision. Many thanks and thanks again for taking the time to write the blog.

    • Thanks for the kind comments Bryan!

      Certainly for our project, FIR has been much less expensive to run upstairs – the bedrooms are mainly in the more modern sections of the house. The larger more open plan sections, are always going to be quite expensive to heat with FIR simply because you are paying / KW / Meter cubed. As for underfloor, perhaps It’s simply down to my experience with particular implementations I have experienced. I am personally quite ‘heat sensitive’ and so it does not take much for me to complain about being either too warm or too cold! Just when you get the temperature right downstairs, it’s way too hot upstairs so you end up opening a load of windows. I’m also a bit of a worrier so I think I would be constantly worried about it breaking / leaking or wanting to ‘re-arrange’ things, and end up and having to dig the floor up. Up to now I have been running FIR programming essentially on all the time, the panels simply switch on and off to maintain temp. For large open plan, especially higher heat loss spaces, this strategy can turn expensive. So an alternate idea is to consider much higher power FIR solutions and ‘flash heat’ zones but only at the times of day they are used. I am currently doing the sums on a solution that will do just this at the moment. I will be posting something up on the results of this update soon.

      For the long term, I might consider looking at ESPs Heliotherm ASHP coupled with a few strategically placed Thermovec rads. The nice thing about this solution is that it can deliver both heating AND cooling – something not possible with a UFH only setup. Perhaps you could combine to two and have the Thermovecs upstairs where it would be hotter in the summer? Heliotherm is not cheap and hence that will be a long term aspiration. For now, cooling is provided by the Ecocent hot water solution, which if you going to look at a non gas UFH solution – Ecocent would would fit nicely.

      As I mentioned on the blog, the benefits of FIR, the low maintenance costs, space saving by ceiling mounting, and just the sensation of getting heat from above.. because I’m a bit of a ‘heat snob’ FIR is definitely my favoured ‘kind’of heat – but it’s definitely not the cheapest!

  6. Martin says:

    Interesting article, but I can’t understand why you keep stressing the importance of UK and EU voltages being different.
    They WERE 240V & 220V, respectively, but I understand that it was mutually agreed that they be harmonised at 230V, way back in 2003! And that is now the case, surely?

    • Hi Martin, thanks for the comments!

      The matter of voltage is extremely important when it comes to FIR. A FIR panel designed to run at 230V but is connected to a 240V supply WILL output a higher wattage and MAY cause over heat tripping issues. This was a problem that I myself experienced in my own property and could only rectify by buying a VO (voltage optimiser) to take down the voltage of my property from 240v to 230v. Yes you read that right, my mains voltage here is 240v, and actually it fluctuates quite a bit depending on the time of day / local demand. Sometimes it’s 235V. Sometimes it’s 245V. I suggest you check your own and you will see!

      The harmonisation of electricity was an nice idea but never really worked out. In the end it was more about creating a single voltage that all appliances could be used ‘with confidence’ with because they were within tolerance. But a device designed to run at 230V ideally should be used on the continent and a device rated for 240V should ideally be used in the UK.

      You can read a bit more on this here : https://www.schneider-electric.co.uk/en/faqs/FA144717/ – these guys know a think or two about electricity.

      You don’t really notice a problem with a washing machine, tumble dryer, cooker, or even kettle.

      But when a FIR panel designed to output 600W @ 230V is placed on the ceiling and it actually supplied 240V (or more) this panel is now going output a higher wattage, and therefore get hotter because of this. You might think being a heater that more heat = good but for FIR panels, it is not the case. It’s actually very BAD. Because the panels have a safety feature that is designed to ‘trip’ if they go over a certain temp, your FIR panel will trip more often, and rather than get longer periods of sustained FIR power output you will end up with constant heat up / trip / cool down / heat up / trip etc. So your panels are pretty much always in a heat up or cool down cycle and FIR production would be much reduced. You pay a lot… to NOT heat a room basically.

      It’s an easy problem to detect because you will heat the panel ‘click off’ continuously.

      This is why it’s important when you are looking for FIR panels, to source from a UK vendor, that has heating elements that are rated for 240V – we recommend Herchel so you avoid this problem, WITHOUT having to go through the pain and cost of fitting a VO – like I had to! You live and learn!


      • Bill Green says:

        Well you have certainly emphasised this issue a lot.
        In fact it sounds like a potential nightmare and something I have never had to consider with a gas central heating system. We installed a Worcester 24 cdi in 1997 which has never had an ‘annual’ maintenance undertaken and still runs like a dream, very quiet. We have had a couple of things replaced that we thought were faulty but further research on my part suggests that was most likely not necessary. Now we will run this till it stops working and replace it with another. We burn about £800 on gas in a large 3 bed detached house for heating, hot water and cooking.
        I found this on the web on the latest UK elec regs:
        For many years the supply voltage for single-phase supplies in the UK has been 240V +/- 6%, giving a possible spread of voltage from 226V to 254 V. For three-phase supplies the voltage was 415 V +/- 6%, the spread being from 390 V to 440V. Most continental voltage levels have been 220/380V.

        In 1988 an agreement was reached that voltage levels across Europe should be unified at 230V single phase and 400V three-phase with effect from January 1st, 1995. In both cases the tolerance levels have become -6% to +10%, giving a single-phase voltage spread of 216 V to 253 V, with three-phase values between 376V and 440 V. It is proposed that on January 1st, 2003 the tolerance levels will be widened to +/- 10%.

        Since the present supply voltages in the UK lie within the acceptable spread of values, Supply Companies are not intending to reduce their voltages in the near future. This is hardly surprising, because such action would immediately reduce the energy used by consumers (and the income of the Companies) by more than 8%.

        In view of the fact that there will be no change to the actual voltage applied to installations, it has been decided not to make changes to the calculations in this book. All are based on the 240/415V supply voltages which have applied for many years and will continue so to do.

        In due course, it is to be expected that manufacturers will supply appliances rated at 230 V for use in the UK. When they do so, there will be problems. A 230 V linear appliance used on a 240 V supply will take 4.3% more current and will consume almost 9% more energy. A 230 V rated 3 kW immersion heater, for example, will actually provide almost 3.27kw when fed at 240 V. This means that the water will heat a little more quickly and that there is unlikely to be a serious problem other than that the life of the heater may be reduced, the level of reduction being difficult to quantify.

        Life reduction is easier to specify in the case of filament lamps. A 230 V rated lamp used at 240 V will achieve only 55% of its rated life (it will fail after about 550 hours instead of the average of 1,000 hours) but will be brighter and will run much hotter, possibly leading to overheating problems in some luminaires. The starting current for large concentrations of discharge lamps will increase dramatically, especially when they are very cold. High pressure sodium and metal halide lamps will show a significant change in colour output when run at higher voltage than their rating, and rechargeable batteries in 230 V rated emergency lighting luminaires will overheat and suffer drastic life reductions when fed at 240V
        The implication is that these FIR devices could suffer significant life reductions thus negating the energy cost savings equally significantly. I guess there is no such thing as a free lunch.

        • Hi Bill,

          Many thanks for your reply.

          Yes certainly there are challenges and considerations, but then there are benefits also. Hopefully other people interested in switching to FIR might avoid some of the issues I came up against – that was sort of the point of writing the blog.

          Any new technology is going to have problems and I suppose when gas central heating first came out, there were quite a few issues with upgrading houses to that also. I would say, to date I have not heard any tales of FIR houses mysteriously exploding (touch wood) so that’s something.

          I can’t speak for any reliability issues with running FIR panels with elements optimised for 230V rather than 240V – I used a Voltage Optimiser to run my panels at 230V. I have nearly 30 panels in my property which were installed around 2015 and still – over five years later, they are all working. Zero failures.

          As I mentioned in the blog – the switch to FIR was not something I did to save money. I simply do not like convective wet central heating, nor do I like underfloor heating. I experienced FIR heating and I really like the type of heat (from above) that panels produce.

          If you are running a gas boiler it’s not a legal requirement to get a gas check every year but obviously it’s recommended. For one reason of another (if you are the cynical sort you might perhaps come to one conclusion!) we always seemed to experience issues with our gas boiler a week or so after the gas check. Fixing it was always painfully expensive. Fancy that!

          I’m not a massive eco-warrior (still have a gas hob!) but I do get some satisfaction that we are 100% heated by non-fossil fuels thanks for our electricity supplier – plus the 4KW array on the roof helps (a bit) in autumn / spring.

          So yes FIR is not for everyone and I get the feeling…. not FIR you!

          Kind regards,


    • Carole Thompson says:

      Hi I have read this article, and found it very interesting, as I am about to purchase FIR heaters for my flat. I spoke to my electrician, and he confirmed that all voltage across Europe including the UK is now 230v. This was done to bring all of Europe to the same standards. But, as Jeff rightly says voltage can fluctuate from as low as 220v to 246v. My electrician confirmed this, but says it won’t cause a problem with most appliances as they are manufactured to work between 220v and 240v. It only causes a problem if the voltage is higher than 240v for prolonged periods of time, which is when you need the voltage optimiser. But he tells me that the majority of domestic properties do not have this problem. T is more likely in a commercial environment. I think you were just unlucky Jeff. But glad you got the problem sorted, and made me aware of it so I could check it out before buying. The product I am buying works on a range between 220v and 240v. So I am happy that it will work fine.

  7. Matt Benton says:

    Thanks for a well written and informative article Jeff. I’ve been looking for a lower carbon alternative to my gas CH, for when my 20 year old boiler gives up the ghost. It’s running efficiently but usually needs a couple of hundred spent on it each year. .I’d also like my gas boiler in the loft instead of in the small bedroom, as it is now, so that will add a little to cost of replacment. And although a more modern boiler might cut gas consumption by 10%, ideally I’d like to cut it 100%.

    Even with RHI ground source heating looks pricey (£6000 in RHI payments, but £12k to install), and there’s a question of whether it can really work in old houses like mine. The house is 1900 brick terrace, with upvc double glazing. But this spring I uprated my loft insulation to a foot deep, and put insulation under the bedroom floors to keep the downstairs warmer, so overall it’s warmer than the average old house.

    I may try an experiment this winter. The 3x4m back bedroom is the computer room which gets a lot of use. Last year I started turning down the CH or turning it off, and just using an electric 0.5kw heater beside me, which did the job on many days. I’m thinking of ceiling mounted FIR panels in there, turning off that one radiator completely, and seeing what the impact is on the electricity bills.

    So I wondered, you say FIR is not cheaper than gas CH. But can you estimate how much more it’s costing? Are we talking 10% more, 30% more or 100% more? This post from greenage suggests a difference of around a third more for FIR, £800 per year instead of £600 per year, https://www.thegreenage.co.uk/tech/infrared-heating-panels/ Does that sound about right?

    Also I get the impression with FIR heaters they are either on or off? Making it unlike a gas CH radiator where heat level can be controlled. Do you notice this switching on off to get up to room up to temp with FIR heaters – is it like constantly going from sun to shade and back again – or does the heat feel more constant than that?

    Got a couple more questions, but I’ll leave it at that for now!

    • Hi Matt,

      Glad you liked the blog – it’s a few years old now but the main FIR considerations are still very much current – nothing has changed in that respect.

      FIR panels are generally ‘digital’ so like you say they are either on or off. This fact actually makes them much easier to control and automate. A panel will be on and you will ‘feel’ it. When the room is at the right temp (usually set lower for FIR – 19c is not uncommon) the panel will switch off, and will remain off until the lower limit is crossed, then it’s on again. Depending on the model of controller / thermostat your panels will stay closer to the ‘set’ 19c (turn off at 19.1, turn on at 18.9) – in which case they are clicking on / off quite often. I run mine so they would click off at 19.5, but not click on again until 18.5. A good system (or one that is integrated into a home automation system) you can modify / heavily customise this. I remember being told once that an average property FIR panels are on 1/3 of the time.

      The single most frequently asked question I get is: “How much is this FIR system going to cost me to run?” and that’s a tricky one to answer, because it would vary depending on your property. For me – definitely MORE expensive. If my property was top floor maisonette with two beds – I’m sure it would definitively be LESS expensive.

      But lets look into some positive factors:

      First thing, is that you say you are in a terrace. If you are not end of terrace, right away that means you are less two large outside walls, so that in itself is a big factor. Even if the front or back of your terrace is north facing – it’s still a much smaller area of outside wall space.

      You’ve up insulated the loft and some floors too = that’s going to help too, as is the double glazing.

      Wet radiator central heating systems can be ‘zonal’ are typically there are just two, with downstairs and upstairs. I have seen multi zone properties where the homeowner is oblivious to this and is running the entire property like a single zone. With FIR every panel can theoretically be a ‘zone’ so you can switch rooms, or even parts of rooms off when they are not needed. So yes you pay more per KW/H than gas, but then with smart controllers (tied in to motion sensing and some learning etc) you can become more efficient in that you only heat what you need, when you need it.

      Running costs, since 2015 I have not spent a single penny on the heating system. So it’s more expensive to run in the winter yes, but there is the hidden cost of what might have gone wrong with a wet system. Boiler repair, water damage etc.

      Negative factors:

      Wiring. It’s an older property – will the wiring cope? Will you be looking at full a re-wire?

      Installation. This can be messy and expensive in particular with ceiling panels on the ground floor. First floor it’s not so bad if you have a loft.

      ‘Weirdness factor’ Some people just find it weird to be heated from above. It’s the best thing about FIR for me, but some people hate it.

      I guess none of this really answers your question about how much more your system will cost to run. Every property is unique, so to work out predicted costs you will need to do some heavy maths with a SAP assessor. But like I said, as a terrace, you are at a big advantage with not having outside walls.

      But let me know how you get on!

      Kind regards,


      • Bill Green says:

        I like the idea of individual zones. But I have found that is possible with wet systems too.
        The most energy saving value for money exercise I did was to fit thermostatic radiator valves. They range in price from £3 to £30 depending on type and source. As soon as the room gets to temperature they turn off the hot water to the rad. Pay for themselves within months.

  8. Matt Benton says:

    Thanks Jeff.

    (btw I said ground source above, actually I was quoted for air source heating, which even with RHI is just prohibitively expensive).

    Luckily the wiring is pretty good (new circuit board installed 3 years ago). I will give one room a go with FIR I think. Using the Herschel calculator the min recommended is one 850w heater, so I’ll install a 540 + 350w, which suits the room layout. It’s interesting also that if I change the calculation from 1 external (uninsulated) wall to 2, this suddenly jumps to 1400w minimum required! Luckily not a problem in my mid terrace.

    From reading around there seems to be a rule of thumb that FIR heaters should be around 3/4 the power of an existing CH radiator. This room has a 1200w radiator, so 890w FIR should do the job. Using the calculator I reckon my 112sqm mid terrace needs only 5.5kw of heaters in total.

    The total cost of heating this house last year was 8000kwh x 3.5p = £280

    FIR cost is possibly 5.5kw x 0.33 = 1815w per hour. (assuming panels are ‘on’ for 1/3 of the time).
    1815w x 6 hours a day = 10.980kw
    10980 x 180 days (6 months ish) = 1960.2kw total
    15p x 1960.2 = £294

    But I see that as a maximum, as I generally have the house to myself, would set 4 or 5 zones, so most of the panels will be ‘on’ for far less than 1/3 of the time.

    If I installed an electric hot water heater and removed the boiler there’s other savings possible; £90 annual service + £200 a year repairs + £60 standing charge for gas. Potentially £350 a year.

    It’s interesting that EPCs are still unfavourable to FIR heaters. Is the industry talking to government at all about getting that changed? Are people in the industry writing to their MPs etc? And the same with getting FIR included under RHI payments?

    One of the main barriers to getting the UK carbon neutral is a realistic alternative to gas CH, so the industry need to be shouting about FIR and get it onto the radar. It should also be attractive to government because lower install costs compared to heat pumps mean the RHI budget can transition more properties off fossil fuels for less government expenditure.

    Hopefully I can get the panels installed this autumn. Expect to see an update around spring next year.

    • Great update. BTW – you can get 10% off Herschel on checkout (I think you quote acchaus as coupon code, or just click on one of our Herchel links).

      We also have a 2nd hand Herschel 600W which we are happy to loan out for basically delivery fee & deposit.

      You might want to check out the EcoCent H/W system which I also have. It takes warm air from say a bathroom and uses it (heat pump) to generate hot water with a COP or around 4. Bonus in the summer, the exhaust (dehumidified air) is cold so we have routed this by a actuated valve / ducting to our master bed. If it’s not possible to route air from a hotter place there is also now an ‘ambient air’ model that just works wherever you stick it.

      Like I said, the external walls are the killers. For flats and terraces, I think FIR is ideal – and you are right, people should be shouting about it.

      Tad envious as the electric bill for my own 200 sq meter house with a BIG north facing solid brick wall…. £300 a MONTH in the winter! But then we have an office, an annex (basically a self contained small flat) and the main house so it not as horrific as all that. We get around £200 per quarter for the PV too which helps (a bit!).


      • Matt Benton says:

        Given the heat demand difference, wouldn’t insulating your North wall pay for itself over a few years? All the grants for external insulation seem to have disappeared now, but dry lining the inside isn’t that expensive?

        Seems to me insulation is a bit like looking for leaks on a boat, weak spots need sealing. I put Thermafleece on the outside of an unplastered back wall which is covered by an outhouse. And at the front I have a small covering roof, 90cm out, running the width of the house and over the lounge bay window. Just lifted some tiles and realised there’s nothing but lath and plaster and tiles to keep the heat from the bay window in, so I may as well have kept a window open all winter! I’ll be up a ladder stuffing Thermafleece in there soon.

  9. Jhon Martin says:

    Nice blog. It will surely help beginners update their knowledge. The efforts you have put in to create the posts are quite interesting. Looking forward to seeing you soon in a new post.

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