Some advice on infrared heaters please.

[HappyHippyDad]

Evening all

I have been asked to quote for installing infrared heating panels (smart) throughout a house. This will be a first for me and I thought I would talk it through on here.

In total 5.8kW. Top floor is 2.7kW (3 panels and a towel panel) and ground floor is 3.1kW (4 panels). These are the panels Select XLS - White Frameless Infrared Panel Heater - https://www.herschel-infrared.co.uk/product/select-xls-white/

There will be a number of smart stats so most of the panels can be individually controlled.

They will be located on the ceiling.

There are 2 socket circuits in the house, 20A top floor, 32a ground.

I was planning on introducing 2 new circuits as it is quite a bit to add to the existing socket circuits. They will have type A 30mA RCD protection

With NSH's each heater would have it's own isolation switch. Would it be necessary for each infrared panel to have an isolation switch? With them being ceiling mounted this would add quite a bit more disruption, i.e having to chase down the wall to locate a FCU or DP switch. I can see it being a good idea, but I wondered if it was breaking the regs?

Any further points to consider?

Thankyou all.

 

[davesparks]

Would it be necessary for each infrared panel to have an isolation switch? With them being ceiling mounted this would add quite a bit more disruption, i.e having to chase down the wall to locate a FCU or DP switch.

Yes each panel should have its own means of isolation so that it can be isolated for maintainence or when it has become faulty.
You don't have to chase all the way down the wall and mount them at socket height though, they can go at high level or even on the ceiling.


Presumably you working to someone else's specification of the type of heater, power ratings etc?

 

[James]

I would look at it like this,
each panel requires A means of isolation.
however, they don’t need individual isolators
a single isolator for heating would be ok in my book.

 

[littlespark]

I was always told IR heaters were wasteful.

They heat bodies, so you feel hot… and surfaces… but they don’t heat air… so thermostats don’t sense it’s hot, and don’t shut off.

Maybe I’m wrong.

 

[davesparks]

I was always told IR heaters were wasteful.

They heat bodies, so you feel hot… and surfaces… but they don’t heat air… so thermostats don’t sense it’s hot, and don’t shut off.

Maybe I’m wrong.

They have their place and do work in some situations, but as you say they heat people and surfaces rather than the air around them.

 

[HappyHippyDad]

Thanks for the advice.
Yes, the client has purchased the heaters and specified where they want them. They are a pretty well informed couple and have clear ideas of what they want, but also open to suggestion and the need to install it correctly, I.e follow regulations.

 

[pirate]

I have installed those hershel panels and 3 years on they have been faultless and very effective in their setting. Being ceiling mounted keeps the walls clear and also prevents accidental damage. There are 2 circuits for these panels in the building, and the means of isolation is via the switched sockets they are plugged into, plus their respective breakers, of course. They have never been turned off, but each circuit is controlled by a thermostat. Normally I would have hard wired them, but as they each came with a plug it made sense to install them on a socket circuit while we evaluated them. It makes it easy to isolate each one, but as I said, 3 years on they just give out the required heat, and have been a success all round. Heating the fabric of the building is a plus in my view, but I guess that not all building types are as suitable. I would add that this is a single storey building, with loft access above the ceiling, so the wiring is all above the ceiling.

 

[HappyHippyDad]

I have installed those hershel panels and 3 years on they have been faultless and very effective in their setting. Being ceiling mounted keeps the walls clear and also prevents accidental damage. There are 2 circuits for these panels in the building, and the means of isolation is via the switched sockets they are plugged into, plus their respective breakers, of course. They have never been turned off, but each circuit is controlled by a thermostat. Normally I would have hard wired them, but as they each came with a plug it made sense to install them on a socket circuit while we evaluated them. It makes it easy to isolate each one, but as I said, 3 years on they just give out the required heat, and have been a success all round. Heating the fabric of the building is a plus in my view, but I guess that not all building types are as suitable. I would add that this is a single storey building, with loft access above the ceiling, so the wiring is all above the ceiling.

Thanks Pirate, that's a good read.
They do come with plugs on, but with them being ceiling mounted the client doesn't want any cable on show. I'll be chopping the plug off (ok'd in MI) and putting on a FCU I think.

Where do you have the sockets? In the loft? Perhaps I could do that on the top floor heaters!

 

[davesparks]

Yes, the client has purchased the heaters and specified where they want them. They are a pretty well informed couple and have clear ideas of what they want

Just keep in mind when doing the job that you may well be going back again in the near future to convert to a more conventional heating method.

 

[brianmoooore]

They heat bodies, so you feel hot… and surfaces… but they don’t heat air…

I was in a largish church last night for a school nativity play. I chose my seat so as to be directly in front of two 9kW (if 1.5kW tubes) wall mounted IR heaters; one each side. I did not feel hot at any time. Head and shoulders slightly less cold than my legs and feet would be more accurate.

 

[pirate]

Yes, HHD, the sockets are in the loft. It's a large space so the rings were easy to install, and thus there is no exposed cabling in the rooms below. The underfloor space in the attic has insulation in it, so lengths of downpipe were fitted and the cable and plug for each heater sits in the pipes, making it easy to unplug and remove a heater if necessary. It's a light industrial building, brick internal and external walls and concrete floor. This seems ideal for IR heating as the fabric heats up. Yes, if you stand underneath a panel you can feel a slight extra warmth on your head, but not unpleasant!

 

[HappyHippyDad]

I've been trying to find any information on in rush current of infrared heaters, to know avail. Could be anywhere between 0 and 10 x. Does anyone have some information on this? I'll contact Herschel to ask also, but it would be interesting to have a chat about it here.

From the little specific information I can find on the net, I am assuming these are resistive heating. They send current to an element and the heat is reflected to desired location.

One more question is how quickly do you feel warm in the area fed by these heaters? My outdoor gym is fed by infrared and I find that I do not particularly notice a big difference when I walk into it (although I do notice some), but I'm soon warm enough, although I start training so this massively warms me up, meaning I'm not sure if it's the heaters or me.

Should you feel a difference when you walk into an area fed by these heaters or do you have to wait for them to heat up you as an object?

Also, if they are heating up the objects, do these object then give off heat which warms the room? I'm guessing not really as they simply wouldn't get warm enough to do that.

 

[littlespark]

In my experience, you turn on an IR heater from cold and it comes on quick. You feel the heat on your skin like a “prickly” heat instantly if standing below it.

Closer body parts heat first… so you could have a sweating head, and frozen hands…

 

[brianmoooore]

The term infra red heater covers a wide range of heater types. Any heater that you can feel direct heat coming from is 'infra red', even though it may be primarily a convector. If you stand a foot away from a standard domestic wet heating radiator, you can feel heat directly, and this is infra red, if you touch it, that's conducted heat, and as it warms the air, that's convected heat.
The two types of high level infra red heaters I've installed are very different from each other. One sort used elements of a similar construction to oven or grill elements, have no significant inrush current at all, and take a while to have any effect, while the other sort uses quartz tubes which light up ruby red, and these have a considerable inrush. The heat from these can be felt instantly.
I have no knowledge of the panels in this thread, but I suspect that inrush currents are low.

 

[marconi]

6kW Soft Start Controller - https://www.herschel-infrared.co.uk/product/6kw-soft-start-controller/

3kW Infra-red Heater Controller with Surge Protection - Leisure Heating - https://www.leisureheating.co.uk/product/3kw-infra-red-heater-controller-with-surge-protection/

3kW Infrared Soft Start Quartz Heating Controller | Fast UK Delivery - https://www.cnmonline.co.uk/3kw-infrared-soft-start-quartz-heating-controller.html#173=

Infresco Remote 2KW – United Automation - https://www.united-automation.com/product/infresco-remote-2kw/

Infrared Heater Controls Guide - Heat My Space - https://heatmyspace.co.uk/faq/infrared-heater-controls-guide/

BN THERMIC HN2 SERIES INSTRUCTIONS Pdf Download - https://www.manualslib.com/manual/1863064/Bn-Thermic-Hn2-Series.html

 

[HappyHippyDad]

The term infra red heater covers a wide range of heater types. Any heater that you can feel direct heat coming from is 'infra red', even though it may be primarily a convector. If you stand a foot away from a standard domestic wet heating radiator, you can feel heat directly, and this is infra red, if you touch it, that's conducted heat, and as it warms the air, that's convected heat.
The two types of high level infra red heaters I've installed are very different from each other. One sort used elements of a similar construction to oven or grill elements, have no significant inrush current at all, and take a while to have any effect, while the other sort uses quartz tubes which light up ruby red, and these have a considerable inrush. The heat from these can be felt instantly.
I have no knowledge of the panels in this thread, but I suspect that inrush currents are low.

6kW Soft Start Controller - https://www.herschel-infrared.co.uk/product/6kw-soft-start-controller/

3kW Infra-red Heater Controller with Surge Protection - Leisure Heating - https://www.leisureheating.co.uk/product/3kw-infra-red-heater-controller-with-surge-protection/

3kW Infrared Soft Start Quartz Heating Controller | Fast UK Delivery - https://www.cnmonline.co.uk/3kw-infrared-soft-start-quartz-heating-controller.html#173=

Infresco Remote 2KW – United Automation - https://www.united-automation.com/product/infresco-remote-2kw/

Infrared Heater Controls Guide - Heat My Space - https://heatmyspace.co.uk/faq/infrared-heater-controls-guide/

BN THERMIC HN2 SERIES INSTRUCTIONS Pdf Download - https://www.manualslib.com/manual/1863064/Bn-Thermic-Hn2-Series.html

Now you're just making me look silly Marconi

Thanks for the reading material, I shall plough through.

 

[pirate]

I can't really say how quickly the room feels warm after switching on, but the panels do heat up quickly. However, in the building I was referring to, these panels have been switched on for 3 years, and the temperature is set on the 2 stats. We have it set on 21 in the social area and 19 in the workshops. The brick walls are slightly warm to the touch so I assume the fabric absorbs and re-radiates some of the heat. This building is a branch of the Men's Shed charity I have mentioned before, and most of the members are, shall we say, of a more senior age group. No-one ever complains of being cold, so, I conclude that it all just works! There are multiple large windows in the walls too, all being new high-performanmce double glazed units.
I just called one of the regular users who said they did put the stats up a couple of degrees earlier this week as the outside temperature was minus 8, but in fact it wasn't necessary as the set temperature had been maintained anyway.
I should mention that these panels are not the latest "smart" ones with lots of different controls and remote switching. However, apart from that I believe they have the same basic technology as the newer ones.

 

[marconi]

Briefly....a convector heater warms the air which then warms the room and then the people. Since hot air rises the warm air goes upwards but over time a convection current of warmed air starts to flow in a circuit from top to bottom to top.......

A radiant heater such as an Infra Red heater shines photons of light on to surfaces such as on people and these photons are absorbed by the surface which then warms up.

Thus IR heaters warm people because they are illuminated (bathed) in light - hence their use at outside venues but useful inside for directed warming effect.

Convection heaters warm people because they are bathed in a flow of moving warmed air- useless for outside venues but works in a contained space.

Warmed air is at a lower temperature than the surface temperature created close to an IR heater. But the IR heater photon flux decays inversely with the distance away squared so the warming effect rapidly decays.

There is also conduction heater which is self explanatory.

 

[pirate]

One point I forgot to mention is how these panels are attached to the wall/ceiling. If the current method is the same as when I installed them, you do have to be careful that the ceiling/wall is completely flat.
Not so critical on wall mounting, but that's because you can generally see behind them from above, but locating them on a ceiling is trickier.
Basically, there is a bracket you fix to the ceiling, and for plasterboard the usual hollow anchors are ideal as the panels are not heavy. Once the bracket is in place, lugs on the back of the panels engage with slots on the brackets, and you slide one way, then at right angles to lock in place. removal means reversing that procedure, so it is best to mount all the brackets in the same orientation, so that to install it's up, push left, slide back...or what ever works for your fitting. Thus, the bracket has to be completely level or one or more of the lugs won't engage in the bracket. I had only 2 out of 12 where the ceiling was slightly bowed, so simply used shims, you know, those plastic ones that come in various sizes in a bag of 500 for a few quid. A spirit level across the bracket will confirm when it is "true". Trying to see the lugs when your face is squashed against a ceiling is not easy! Also, if you make them all the same orientation, it's easy to stick a discreet label on one edge of the panel saying "Slide to left, then pull" or whatever.
So far we haven't had to remove any of the panels, so the above advice comes simply from my "dry run" at first installation. A small point, but hopefully of help. Finally, when installing the bigger panels, it's so much easier with 2 people.

 

[freddo]

so thermostats don’t sense it’s hot, and don’t shut off.

'Black bulb' thermostats should be used for this application rather than standard air thermostats.