Infrared for Home Energy

[bungeejumper]

I started this thread with the hope I would hear from home-owners who have gone down the route of switching their homes to all-electric. Replies have been helpful and interesting but none have been from significant home infrared home owners. Before you quip they don't exist I've just saved you the effort.

How? Have you found infrared heating supporters on another forum? Or have you just spent more time on reading more marketing blurb?

Well, fair enough, I guess you have indeed saved us the effort. The effort, that is, of running repeatedly through all the relative cost calculations, which as far as I know are common knowledge. (I.e. that electric energy is four times as pricey as gas energy, kilowatt for kilowatt, although you can (almost) break even with air source heat pumps if they deliver on their three-for-one return on useable heat.) The snag: that heat pumps are not what you're not proposing to use.

You've accused us of spreading falsehoods about bathroom ceilings, when you could have made the same point by saying that there are other views (and then linking to them.) Forgive me for saying that you've obviously made up your mind in favour of infra-red, and good luck to you. (Sincerely.) Looking forward to hearing how it's going in a year's time.

But don't rip the gas boiler and radiators out just yet. As my old dad used to say, the cruellest four little words in the English language are the ones that go "I told you so".

BJ

[DrFfybes]

1. Some time in the not so distant future, we will all need to stop using gas central heating and petrol/diesel cars.
2. There seem to be some misconceptions/out-of-date ideas about infrared as a source of clean energy.
3. The main alternative to gas central heating currently seems to be some sort of heat exchange/air source system. How do these compare with infrared?

For point 1) not so distant is probably not in the next 20 years. The CURRENT proposal is that sales of replacement gas boilers will be banned from 2035, rather than the much misreported banning of existing installations. So there will be a mad rush to replace existing gas boilers in 2034, or more likely 2039, or whenver it actually comes in. Modern gas boilers don't last like they used to, but I can see Gas boilers still being in popular use well into the 2050s.

2) I don't really think there's much info out there yet. Rather like Heat Pumps, Electric cars, and Rabbit Phones, it takes a good amount of initial uptake to generate real world data, technology will move fast so early systems quickly become obsolete, and there will be a lot of suspicion and misinformation.

3) ASHPs are evolving at a rapid rate. New pumps are coming out that can provide a much hotter flow, typicall ver 60C and still claim the same efficiency as the older cool flow models. Effectively these will soon be a direct replacement for a gas boiler, keeping the same radiators and control systems. Ans if they can be even more efficient at a lower temp, then in Spring and Autumn they will be cheaper than gas to run, especially if the expected closing of the gap between gas and electric rpices materialises as renewables reduces the link.

The first point is obvious but I wonder how many people have really thought about what that will mean for them. Maybe I am guilty of misconceptions but from what I read these systems require substantial home alterations including replacing radiators, finding space for equipment as well as being expensive. Also, from my personal experience with friends who have installed ground source home energy, the system does not provide a sufficient level of heat and must be supplemented with something else such as a woodburner/electric fire etc.

See above. Ground source is very expensive and inefficient, it seemed like a good idea for a while, but air source has overtaken it. An LG 16kW HT air to water system is now about £3k with all the gubbins
https://www.theheatpumpwarehouse.co.uk/ ... door-unit/

We replaced our gas boiler last year, but next time it is up for replacement I suspect this is the route we will take, bearing in mind we have a rambling 5 bed place dating back to the 1790s. But I'm not going to jump at it yet, I'll wait until they become more established.

I will continue to research the issues involved before I commit to a home without gas but so far, apart from cost, I do not see any downside to infrared, combined with solar panels and a log-burner.

So what you are saying is that you think IR will still require a log burner, which let's face it, negates the idea of going green in the first place. It might be carbon neutral, but with their increasing popularity in some areas it is already starting to smell like the winters of my childhood.

We have Air to Air (also often known as 'split' units) in some rooms, provides good quick cheap room heating (like about 10p/hour cheap in a 4x5m room) which have the benefit of summer cooling. Basically a heat pump version of the stuff seen all over the continent hanging off the balconies of flats etc.

But as V8 says - IR heaters are pretty cheap. Try one and report back

Paul

[yieldhog]

As V8 says - IR heaters are pretty cheap. Try one and report back.

I am thinking of doing just that. First thoughts are to place a picture type wall panel in the stairwell facing towards the stairs. There are no obstructions in this area so it will give us a good idea of how much heat is generated and the reach of the heat. The only issue is finding the nearest power source and installing a plug-in point.

Y

[Tedx]

There was a guy on YouTube who had an 800w panel on his ceiling wired into the lighting circuit. In my limited knowledge his explanation seemed to suggest that there was enough capacity (particularly with LEDs fitted throughout)..….but would you risk it?

[DrFfybes]

There was a guy on YouTube who had an 800w panel on his ceiling wired into the lighting circuit. In my limited knowledge his explanation seemed to suggest that there was enough capacity (particularly with LEDs fitted throughout)..….but would you risk it?

In theory it is OK, lighting tends to have a 5 or 6A supply and 800W is only just over half that.

Depends what else is tapped of the lighting circuit - shower pumps, CH boiler pump, add in a couple of incandescent outside lights and 3 striplights in the garage or under the kitchen cupboards and you're soon sailing close to the wind.

But would I run my heating from the lighting circuit? Not if it was downstairs, I'd lift the upstairs floor and run a fused spur off the ring main.

Paul

[DrFfybes]

There was a guy on YouTube who had an 800w panel on his ceiling wired into the lighting circuit. In my limited knowledge his explanation seemed to suggest that there was enough capacity (particularly with LEDs fitted throughout)..….but would you risk it?

In theory it is OK, lighting tends to have a 5 or 6A supply and 800W is only just over half that.

Depends what else is tapped of the lighting circuit - shower pumps, CH boiler pump, add in a couple of incandescent outside lights and 3 striplights in the garage or under the kitchen cupboards and you're soon sailing close to the wind.

But would I run my heating from the lighting circuit? Not if it was downstairs, I'd lift the upstairs floor and run a fused spur off the ring main.

Paul

Actually another thought. 800W????? That's the same power as our microwave.

It's about 3x what our heat pump uses, so enough to heat half a house. What size room is he heating?

Paul

[Tedx]

Dunno. It was a while ago I watched the vid. I'll have a look.

[9873210]

As V8 says - IR heaters are pretty cheap. Try one and report back.

I am thinking of doing just that. First thoughts are to place a picture type wall panel in the stairwell facing towards the stairs. There are no obstructions in this area so it will give us a good idea of how much heat is generated and the reach of the heat. The only issue is finding the nearest power source and installing a plug-in point.

Y

Infrared heaters should be in line of sight to the people that want to keep warm (i.e. in the same room). If it's line of sight it can take advantage of radiative coupling and keep people warm without heating air and other things. Not heating other stuff can reduce energy usage. The stairs would usually be a poor place for an infrared heater since it's mostly unoccupied space. In unoccupied space "infrared" is only an indirect air heater, and no different from the oil filled convectors mislabeled as radiators.

[servodude]

In theory it is OK, lighting tends to have a 5 or 6A supply and 800W is only just over half that.

Depends what else is tapped of the lighting circuit - shower pumps, CH boiler pump, add in a couple of incandescent outside lights and 3 striplights in the garage or under the kitchen cupboards and you're soon sailing close to the wind.

But would I run my heating from the lighting circuit? Not if it was downstairs, I'd lift the upstairs floor and run a fused spur off the ring main.

Paul

Actually another thought. 800W????? That's the same power as our microwave.

It's about 3x what our heat pump uses, so enough to heat half a house. What size room is he heating?

Paul

It's going to be equivalent to the old heat lamps one used to see in tiny bathrooms... https://jdlighting.com.au/brilliant-velocity-ii-quattro-3-in-1-bathroom-heat-light-exhaust-fan.html
- they weren't very good

[bungeejumper]

Actually another thought. 800W????? That's the same power as our microwave.

It's about 3x what our heat pump uses, so enough to heat half a house. What size room is he heating?

It's going to be equivalent to the old heat lamps one used to see in tiny bathrooms... https://jdlighting.com.au/brilliant-velocity-ii-quattro-3-in-1-bathroom-heat-light-exhaust-fan.html
- they weren't very good

I've just had a google through the websites that talk about infrared safety, and almost without exception they are from companies that sell them. Nothing very strange about that, I suppose. They mostly draw a distinction between short-wave infra-red, which can be very dangerous indeed, and medium or long-wave, which is the kind normally found in heaters.

But quite a few do warn that poor infrared devices can burn skin or even damage your eyes. (You can't see IR, so you wouldn't necessarily know it was happening.) I've seen several sites warning that children, old people or pets should generally be kept away from panels. (And how are you going to achieve that?)

The elephant in the room, though, seems to be that IR's biggest advantage - that it directly heats the people in the room, not the air - can prove to be a bit of a double-edged sword. If it's beaming at your TV armchair that'll feel fine, but you might feel the chill if you move out of the zone. Sit at a table and you might find your legs getting cold. Don't ask how it'll deal with a party, where the hot and cold zones in the room might make for some interesting interpersonal dynamics.

Nothing that can't be addressed with a few additional oil-filled radiators, of course. But I'd hold off from scrapping the central heating if I were the OP.

BJ

[Spet0789]

To the point about solar panels and seasonal variation. I have a large solar panel installation (30 panels), roughly south facing.

In June of 2023 I generated 1,100 kWh. In December, 150 (admittedly gloomy). January this year was 340 kWh.

So solar panels are a poor partner to electric heating.

One of my big electricity consumption items is the air-source heat pump for our pool which starts running in April / May - so my annual consumption pattern fits my solar panels a bit better.

Of course in countries hot enough to justify air conditioning they are better still (although for the geeks, the efficiency of panels falls when temperatures rise, and in direct summer sun even in the U.K. those panels can appproach 100 deg C). So May / June tend to be better months than July / August.

[BullDog]

I suspect the final analysis is that nobody here has converted their house wholly to IR heating from other forms of heat. That speaks volumes, I think.

If I were to be forced to abandon my gas boiler, the only realistic electric alternative I can see is storage heaters. I have a 7.5p overnight tariff for my BEV but that could equally be deployed in running storage heaters. The cost per kwhr of the off peak electricity would then be about equal to my gas tariff. But then of course, I would I fact need more space in the rooms than is presently taken up by CH radiators.

[yieldhog]

DrFfybes wrote:

"See above. Ground source is very expensive and inefficient, it seemed like a good idea for a while, but air source has overtaken it. An LG 16kW HT air to water system is now about £3k with all the gubbins
https://www.theheatpumpwarehouse.co.uk/ ... door-unit/"

When we lived in California, we used what I think might have been what you are talking about here. We used it to heat a small cottage(in-law unit) in our garden. It provided very efficient heat/aircon and was briliant. But, it needed an exterior unit as well as the interior part, plus I think we needed another energy source to heat hot water for the bathroom and kitchen sink.

I will do some more reasearch on air source energy. £3k sounds very cheap but how many would you need for a 5-bed detached house, how many external units, how would you heat water etc.etc. ????

Y

[DrFfybes]

When we lived in California, we used what I think might have been what you are talking about here. We used it to heat a small cottage(in-law unit) in our garden. It provided very efficient heat/aircon and was briliant. But, it needed an exterior unit as well as the interior part, plus I think we needed another energy source to heat hot water for the bathroom and kitchen sink.

You are getting confused between two very similarly named implementations of the same technology - air to air, and air to water. I really don't blame you, we had exactly the same problem when we started to look at them.

The outside unit for both is pretty similar - it is an Air Source Heat Pump which uses the same 'fridge' technology to compress a gas and shft heat. They are rated by the heat they can output, although the amount of electricity they consume is generally 20-30% of the output because they shift heat from the air into a compressed gas rather than heating the gas directly (or something like that anyway ) the thing is they use a lot less energy than they put out, unlike a gas boiler which uses more energy than it transmits into the pipework.

The system you are thinking of is an air to air system (becoming more commonly known as a 'split' system). In this case a unit outside is connected to one or more ('multisplit') internal wall mounted units, which can blow hot or cold air into the room. The output from the external unit is pumped to the in-room unit were air is blown over a heat exchanger which heats (or cools) the air. Typical cost is about £1k per room, but there are limits on how many external units you can have under UK planning law, and one external unit can ony service a limited number of rooms and the in-room unit generally fits on an external wall. Warm air tends to come out circa 40C. The external units are generally rated up to 2 or 3 kW of heat output.

The other system is commonly referred to as a Heat Pump system (although both are ASHP) but the external units are sometimes still confusingly called 'splits'. There is a larger unit that sits outside and connects to your existing hot water system - ie the pipework from your heating system goes through this instead of your gas boiler. The main downside is/was that until very recently, the water leaving these units was quite cool - typically 45C max, which meant that your radiators never got 'hot' so to get the same heat input into the house you needed to fit larger rads, and often needed to upgrade the insulation as they couldn't provide enough heat to keep up with the loss from the house. This was messy and expensive, and due to the lower running temp the response was slower so you'd need it on earlier in the morning. However there are newer ones coming out that use different gases inside them and can supply water up to 80C, which means they can pretty much be a direct replacement for your gas boiler. Outputs of up to 15kW are pretty typical but they can also be stacked if a higher output is needed. However they do not yet (AFAIK) have ones that can supply hot water on demand like a combi gas boiler, so you need a separate hot water cylinder.

If you have a smart meter and 30 min measures of your gas use you can see how much you currently use at peak consumption. We have a Vaillant gas boiler which can put out (I think) 28kW of heat, apparently needed for our place. This was new last year and modulates the output so if the returning water is warm it turns itself down. With a flow temp set to 65C the maximum it ever uses in the first 30 min it is on is 12kW (presumably it runs flat out initially to get the system hot), and uses up to 18kW in the first hour. Once running for longer it settles about 8-10kW per hour, so the boiler is obviously oversized for the property (as I suspect are most of the boilers out there). I reckon a 16kW high temp heat pump unit would amply replace our gas boiler when the time comes, just needing to come on about 10 min earlier in the morning to compensate for the slightly slower warmup time.

To the point about solar panels and seasonal variation. I have a large solar panel installation (30 panels), roughly south facing.

In June of 2023 I generated 1,100 kWh. In December, 150 (admittedly gloomy). January this year was 340 kWh.

Our small East-West garage mounted array generated 8kWh total in Dec - that was usually beaten in a day in August and even by some days well into October. Jan was 26kWh total, already well exceeded this month. The South facing panels will be installed once the house roof is replaced, which should be later this month, although the bu66ers only turned up for 2 days this week and 2.5 the week before

Paul

[9873210]

They mostly draw a distinction between short-wave infra-red, which can be very dangerous indeed, and medium or long-wave, which is the kind normally found in heaters.

But quite a few do warn that poor infrared devices can burn skin or even damage your eyes. (You can't see IR, so you wouldn't necessarily know it was happening.) I've seen several sites warning that children, old people or pets should generally be kept away from panels. (And how are you going to achieve that?)

You'll find the same warnings for radiators and hot water taps. The way to keep the panels away from pets etc. is to put the IR panels on the ceiling, something you can't do for traditions radiators that are really convectors. And design a home heating system and not an industrial paint curing oven.

Heating is a classic example of "the dose makes the poison". People die from heat exhaustion in conventionally heated houses. It takes bad luck but it does happen. Has been thus ever since the domestication of fire.

[bungeejumper]

But quite a few do warn that poor infrared devices can burn skin or even damage your eyes. (You can't see IR, so you wouldn't necessarily know it was happening.) I've seen several sites warning that children, old people or pets should generally be kept away from panels. (And how are you going to achieve that?)

You'll find the same warnings for radiators and hot water taps. The way to keep the panels away from pets etc. is to put the IR panels on the ceiling, something you can't do for traditions radiators that are really convectors.

No, they get hotter than any of those things. The most effective operating temperature is between 90 and 100C, compared with 60-70 for normal radiators, or 60-ish max for hot water taps. You can put an IR panel on the ceiling, but from what I'm reading it wouldn't do the timber or the plaster much good if the ceiling was old. (Ours are all horsehair, lath and plaster.) Fortunately, though, we are in a minority.

BJ

[9873210]

You'll find the same warnings for radiators and hot water taps. The way to keep the panels away from pets etc. is to put the IR panels on the ceiling, something you can't do for traditions radiators that are really convectors.

No, they get hotter than any of those things. The most effective operating temperature is between 90 and 100C, compared with 60-70 for normal radiators, or 60-ish max for hot water taps. You can put an IR panel on the ceiling, but from what I'm reading it wouldn't do the timber or the plaster much good if the ceiling was old. (Ours are all horsehair, lath and plaster.) Fortunately, though, we are in a minority.

BJ

Yes. Heating systems are literally or figuratively playing with fire.

It's true you need to trade off various different risks, and design for interactions with the structure, but metathesiophobia is not a good look. Professional help is available.
 
https://www.dailymail.co.uk/news/articl ... nutes.html
https://www.birminghammail.co.uk/news/m ... r-20554213
https://www.nidirect.gov.uk/articles/ke ... and-scalds
https://cbtrust.org.uk/get-informed/cau ... er-scalds/
https://www.hse.gov.uk/healthservices/s ... urning.htm

[XFool]

I've just had a google through the websites that talk about infrared safety, and almost without exception they are from companies that sell them. Nothing very strange about that, I suppose. They mostly draw a distinction between short-wave infra-red, which can be very dangerous indeed, and medium or long-wave, which is the kind normally found in heaters.

Why is short-wave infra-red "very dangerous indeed"? After all, very short-wave "infra-red" is just red light!

To put it another way, if short-wave infra-red is "very dangerous indeed", then sunlight must be lethal! Vampires, beware?

Is somebody confusing infra-red with ultra-violet, here?

[servodude]

I've just had a google through the websites that talk about infrared safety, and almost without exception they are from companies that sell them. Nothing very strange about that, I suppose. They mostly draw a distinction between short-wave infra-red, which can be very dangerous indeed, and medium or long-wave, which is the kind normally found in heaters.

Why is short-wave infra-red "very dangerous indeed"? After all, very short-wave "infra-red" is just red light!

To put it another way, if short-wave infra-red is "very dangerous indeed", then sunlight must be lethal! Vampires, beware?

Is somebody confusing infra-red with ultra-violet, here?

SWIR will burn through your retina before you realise it.
A CD laser is 780nm so just invisible enough that there is some energy bleeding in to the visible to give the bright red dot you might have seen (DVD are down in the visible so seem "scary as" if you've been used to the older things). Even in a reader where the power is ~1.5mW it's in an area about 20um wide - typically a burner will be pulsing up around the 30-40mW.
You won't notice the damage because you'll just have streaks of dead sensor cells that your brain doesn't receive info for - it's taken out much like your natural blind spot.
If you're working with this stuff you'll probably get quarterly eye exams to make sure you've not scarred yourself too much, but that's just HR theatre because the damage is done.

Once the wave length is long enough it's felt like heat - but similarly you shouldn't stare at the sun - but if you do at least you'll know about it

-sd
(where most of that early s was on optical storage systems)

[servodude]

I suspect the final analysis is that nobody here has converted their house wholly to IR heating from other forms of heat. That speaks volumes, I think.

If I were to be forced to abandon my gas boiler, the only realistic electric alternative I can see is storage heaters. I have a 7.5p overnight tariff for my BEV but that could equally be deployed in running storage heaters. The cost per kwhr of the off peak electricity would then be about equal to my gas tariff. But then of course, I would I fact need more space in the rooms than is presently taken up by CH radiators.

Storage heaters are a terrible user experience, having to decide how warm or cold you might feel tomorrow?

Why not store the electricity rather than the heat?
Battery packs can't be much bigger than storage heaters, and I'm pretty sure that by the time such a conversion would be necessary there will be decent options for interfacing in to legacy radiator systems