Storage wall heaters

[gazdkw82]

I need to put some storage heaters in a large room. It's around 50 square meters.

Energy efficiency is my number one priority. What is the leading energy efficient technology when it comes to wall heaters?

Last time I fitted some, infrared was the leading form

 

[happysteve]

Depends entirely on the insulating properties of the space.

If very little insulation (and/or very high ceiling), then radiant (infrared) is the way to go.

If well insulated, then convector heaters is the way to go.

Also depends on what sort of heating cycle you need to maintain - just on occasionally, or keeping the room at a fairly constant temperature.

Not an expert on individual types of heater, but the above is the basic principles.

Energy efficiency is a bit of a weird one with heaters. Pretty much all heaters are 100% efficient, in that all the electrical energy goes to heat, and heat is what you're trying to get! Normally when you talk about energy efficiency, you mean the bit that DOESN"T go to heat!

But you can think of it in terms of what you heat. With radiant heaters, you're heating solid objects, but not really heating the air up. Turn off the heaters, and it soon gets cold. With convector heaters, you're heating the air. But if there's no roof (or a very high roof, or a roof with very little insulation) then that lovely warm air won't do much heating of the things you probably want to heat.

 

[James]

Agree with you @happysteve
pretty much all electric heaters have a near 100% efficiency.
strictly speaking the least efficient are the ones that you can see giving off bright light, as some of the energy is being converted to light that is not all converted back to heat.

however, for electric heating, 100% efficient is somewhat misleading.
an 70% efficient gas boiler is likely to be cheaper to run than a 100% efficient electric heater.

before you all slate me for promoting gas instead of electric heating on an electricians forum, consider the following.

even a simple heat/cool air conditioner unit has a cop of around 3
meaning that for every 1Kw of electrical energy it consumes, it gives out 3Kw of heat.
therefore its efficiency is 300%

the downside of it is that heat pumps (air conditioners) become less efficient as the temperature drops. so they may only be 200% efficient when the temp drops to 2 Degrees outside.

ground source heat pumps can give 3 to 4 hundred percent efficiency in the right environment.

my point is, peoples perceptions are often wrong, a salesman telling you that there electric heater is 99.8% efficient is likely to get the order against a gas salesman that is 70% efficient. but the best product may well be a heat pump that is 300% to 400% efficient.

has that got you all thinking????

 

[Grant1987]

Agree with you @happysteve
pretty much all electric heaters have a near 100% efficiency.
strictly speaking the least efficient are the ones that you can see giving off bright light, as some of the energy is being converted to light that is not all converted back to heat.

however, for electric heating, 100% efficient is somewhat misleading.
an 70% efficient gas boiler is likely to be cheaper to run than a 100% efficient electric heater.

before you all slate me for promoting gas instead of electric heating on an electricians forum, consider the following.

even a simple heat/cool air conditioner unit has a cop of around 3
meaning that for every 1Kw of electrical energy it consumes, it gives out 3Kw of heat.
therefore its efficiency is 300%

the downside of it is that heat pumps (air conditioners) become less efficient as the temperature drops. so they may only be 200% efficient when the temp drops to 2 Degrees outside.

ground source heat pumps can give 3 to 4 hundred percent efficiency in the right environment.

my point is, peoples perceptions are often wrong, a salesman telling you that there electric heater is 99.8% efficient is likely to get the order against a gas salesman that is 70% efficient. but the best product may well be a heat pump that is 300% to 400% efficient.

has that got you all thinking????

Haha I understand what you’re saying however I’ve been fortunate enough to learn/understand/install the new smart electric heaters and not only that but the electric boilers I can’t give you the statistics right now but it’s not all doom and gloom for the electrical side of heating gas is the one on the decline and renewable/hydro is on the up which all involves electric ?

 

[Grant1987]

Haha I understand what you’re saying however I’ve been fortunate enough to learn/understand/install the new smart electric heaters and not only that but the electric boilers I can’t give you the statistics right now but it’s not all doom and gloom for the electrical side of heating gas is the one on the decline and renewable/hydro is on the up which all involves electric ?

Stick to the electrics work will always be there and don’t put it down.

 

[pirate]

I like the infra red heaters and installed them in an industrial setting a couple of years ago. We used half the output recommended and all has been fine. I think we just did a better calculation than the on-line calculator specified. They are clean and silent and easy to install and take up very little room. They are light in weight, and fitted to the ceiling. I have old Dimplex storage heaters in my home, and they aren't pretty, but actually quite efficient. If I were to replace them for aesthetics I would go with infra red, but the cost to change would take years to recoup...

 

[Grant1987]

I like the infra red heaters and installed them in an industrial setting a couple of years ago. We used half the output recommended and all has been fine. I think we just did a better calculation than the on-line calculator specified. They are clean and silent and easy to install and take up very little room. They are light in weight, and fitted to the ceiling. I have old Dimplex storage heaters in my home, and they aren't pretty, but actually quite efficient. If I were to replace them for aesthetics I would go with infra red, but the cost to change would take years to recoup...

I don’t think the infra red heaters are suitable for domestic properties don’t they get incredibly hot and costly they are more suitable to limited heat use in commercial/industrial units the whole purpose of the smart storage heaters is to save on cost/power consumption and safety

 

[Mike Johnson]

There is no doubt that air source heat pumps are the most efficient, combine them with wet UFH (40deg) and you probably have the most efficient method of heating any space. Then there are thermal stores with solar panel technology, combining them is very expensive to instal, but the cheapest to run.

 

[pirate]

Yes, infra red panels get hot, but not excessively so. They have designs especially for the domestic setting, including mirrors and pictures to hang on the wall. They should have a thermostatic control device, of course. Some have this built in to each panel, some require to be controlled by a separate stat. My current old-fashioned Dimplex ones will burn you at full heat if you touch them for a short period...i mean they get really hot, and so do some normal ch rads. If I were to engage on a new-build I would go with infra red panels for efficiency, aesthetics and ease of installation/replacement, and none of that nasty gas stuff and no water leaks/burst pipes etc and annual servicing. However, changing over from a previous system is certainly not cost-effective in the short term.

 

[gazdkw82]

Thanks for all the info.....

The space is a room within a church. It is 20 square metres in total. 2metre high ceiling and will be used sporadically for a few hours at a time.

With this in mind I think infrared may be the best way.

These are the ones that the church have found and seem keen to go with.

https://www.ebay.co.uk/itm/Infrared...691084?hash=item5957e4a30c:g:zR8AAOSwikJcASxW

 

[UNG]

Haha I understand what you’re saying however I’ve been fortunate enough to learn/understand/install the new smart electric heaters and not only that but the electric boilers I can’t give you the statistics right now but it’s not all doom and gloom for the electrical side of heating gas is the one on the decline and renewable/hydro is on the up which all involves electric ?

The cost of heating anything by electric has never stacked up even using economy 7 or any of the other variants offering cheap off peak electricity

 

[pirate]

I hear what you say, Ung, and I don't disagree entirely, but in some situations electricity is the way to go, and for some, the ease of installation is a factor compared with the more disruptive and expensive provision of a gas or oil boiler, radiators and associated pipework and the annual servicing costs, risk of burst pipes and the volatility of gas and oil prices. There is also an argument that with more "green" electricity being produced we may eventually see electricity as a noticeably cheaper option. On a different slant, more blocks of flats are being built with no gas installed. A new build is a perfect opportunity to maximise the efficiency of electric heating, the ease of installation/repair/replacement/upgrade...sadly, the quality of many new build properties, especially from mainstream builders, is so poor as to negate in part the benefits I suggested above...
Carbon emissions are a different subject, of course. Electricity has to be generated somehow, and wind power and hydro power are the way forward imho, and tidal generation is still in its infancy, but is free, clean and constant so should be developed along with other methods.

Gazdkw82, please do let us know the outcome of the church installation, ease thereof, power output selected and the construction of the space in question, walls, floor and ceiling etc. I think this would be of great interest to this forum.

 

[gazdkw82]

Was the PIR you installed a relay contact output or solid state output?

Gazdkw82, please do let us know the outcome of the church installation, ease thereof, power output selected and the construction of the space in question, walls, floor and ceiling etc. I think this would be of great interest to this forum.

Concrete floor, solid masonary, plastered walls.

A couple of small windows to outside.

The room is being used as a small service room. Maximum 20 people at any one time.

Ideal temp is 14-17. Too warm and people will prob fall asleep

 

[UNG]

I hear what you say, Ung, and I don't disagree entirely, but in some situations electricity is the way to go, and for some, the ease of installation is a factor compared with the more disruptive and expensive provision of a gas or oil boiler, radiators and associated pipework and the annual servicing costs, risk of burst pipes and the volatility of gas and oil prices. There is also an argument that with more "green" electricity being produced we may eventually see electricity as a noticeably cheaper option. On a different slant, more blocks of flats are being built with no gas installed. A new build is a perfect opportunity to maximise the efficiency of electric heating, the ease of installation/repair/replacement/upgrade...sadly, the quality of many new build properties, especially from mainstream builders, is so poor as to negate in part the benefits I suggested above...
Carbon emissions are a different subject, of course. Electricity has to be generated somehow, and wind power and hydro power are the way forward imho, and tidal generation is still in its infancy, but is free, clean and constant so should be developed along with other methods.

Gazdkw82, please do let us know the outcome of the church installation, ease thereof, power output selected and the construction of the space in question, walls, floor and ceiling etc. I think this would be of great interest to this forum.

Ahh the rose tinted glasses view that the abundance of not so free and not so cheap electricity from renewable sources is going to be the saviour of the world. I doubt with the amount of investment in green electricity that it will ever be that cheap as we move to a more electricity hungry society as gas is forced out of the market electricity will become the new "oil" and demand will drive the commodity price higher, let's not forget the 70's when north sea gas was going to be that cheap it wouldn't be worth billing it yet the bills went up, now in the north sea we have offshore wind turbines given salt water takes no prisoners what longevitity and maintenance cost will they have. Also with a higher dependence on electricity we are creating more peak demand so will the cheaper off peak tariffs disappear as the growth in EV's and other power hungry needs increases

The cost of the heating equipment whether it is using gas or electric is comparable and installation materials and labour if priced up are probably not too different, over the years in all the cases I've looked at the running costs are always the sticking point even taking into account maintenance and servicing costs

Having recently been involved in a new build Passivhaus project it appears that this will in the future be the way forward as to whether it can produce affordable property remains to be seen but the savings in energy usage in the long term will give it it's affordability

 

[pirate]

I agree with your views on this UNG, in part at least. I'm not deluded about the view of cheap electricity being the saviour of the world, but if new properties were built to the correct specification, and your experience with Passivhaus, shows that much can be done to save energy and thus cost. However, building the perfect house will be unaffordable for most people...
I guess there is no easy or overall correct answer, given the ariables involved, but it's a fascinating topic, to me anyway!

gazdkw82, thanks for those details about the construction of the room. From my limited experience, such construction is a perfect match for infra red heating, as it is identical to the recent installation I mentioned originally. If you can install the heating on the ceiling, that would be a bonus in a number of ways.