RADFLEK: Reflective radiator back

Screwdriva

Quite surprised this isn't a better known energy saving product. It reflects wasted energy from the radiator rear to the the front. It's extremely low cost so should pay for itself very quickly. Just ordered a set but thought I'd ask if anyone had any hands on experience?
http://www.greensteve.com/3364/radflek-radiator-reflector-review-not-just-hot-air/

AntonyTewks

I got these. I already have a fairly modern build with added cavity wall so the benefit was going to be minimal but like you say for £20 why not. Not sure I've really noticed a difference but not sure that I would. Only a slight difference would be needed for payback, that might mean the heating going off 5 minutes sooner. I wouldn't know but would save a smidgen each time. If nothing the I guess I can live without the 20 quid

Cardew

This has been discussed many times on MSE and these reflectors are one of those devices that subjectively seem to be a good idea, but for allmost all applications save virtually nothing. This is an extract from an old thread:

  There has been a lot of discussion about these on MSE over the years. IMO and others, they don't save anything at all - others disagree, but nobody can produce test results.
However this subject was raised with the Energy Saving trust(EST) and the following post from another thread might be of interest.

The question of savings with these foil panels was raised with the Energy Saving Trust in this thread: (only read the first couple of pages)
http://forums.moneysavingexpert.com/showthread.php?t=2867980&highlight=energy+saving+t
rust
Essentially the EST stated:
Radiator reflector panels do generate a small saving. In a typical 3 bedroom semi detached gas heated home they can save around £6 and 30kg CO2 a year if professionally installed, whereas DIY installation would save around £3.50 and 18kg CO2 a year. Individually radiator panel reflectors save on average around £1 and 6kg CO2 per radiator as a DIY installation.
We calculate these savings by collating a number of sources. We use the CERT Technical Guidance to derive the average radiator panel saving
from the two different installation types; we then apply average number of radiators for each house type which is sourced from the Building Research Establishment’s ‘Standard Dwellings for Modelling’ (not publically available).
Energy

We then applied our own calculated average prices sourced from
Ofgem data (not publically available) and DEFRA’s GHG Conversion Factors to get financial and CO2 savings.

However when challenged the EST admitted that they had misread the CERT guidance and that those annual savings(i.e. £6 or £3.50 for a whole house) only applied to houses with solid walls i.e. without cavity walls.
A reduction in carbon emissions can only be awarded for the installation of radiator panels when they are fitted to external walls.
Furthermore, research by the BRE indicates that an improvement in energy efficiency from an installation of
radiator panels is minimal if the radiator is fitted on a wall with a filled cavity. Therefore, radiator panels should be installed on either solid walls or walls with unfilled cavities.
So EST have conceded that foil behind radiators in a house with insulated cavity walls hardly saves anything - perhaps a few pence per year.

EricMears

Cardew said:

This has been discussed many times on MSE and these reflectors are one of those devices that subjectively seem to be a good idea, but for almost all applications save virtually nothing. This is an extract from an old thread:

  There has been a lot of discussion about these on MSE over the years. IMO and others, they don't save anything at all - others disagree, but nobody can produce test results.
However this subject was raised with the Energy Saving trust(EST) and the following post from another thread might be of interest.

The question of savings with these foil panels was raised with the Energy Saving Trust in this thread: (only read the first couple of pages)
http://forums.moneysavingexpert.com/showthread.php?t=2867980&highlight=energy+saving+t
rust
Essentially the EST stated:
Radiator reflector panels do generate a small saving. In a typical 3 bedroom semi detached gas heated home they can save around £6 and 30kg CO2 a year if professionally installed, whereas DIY installation would save around £3.50 and 18kg CO2 a year. 

Within that thread, the question "There is a big difference in the saving between a DIY and professional installation, why is this?" was asked but I couldn't see it answered !

Possibly they were taking the view that a 'professional' would always take the radiators off and fit panel to wall before replacement (maybe even flush the radiator whilst it was off ?) whereas an amateur might just stuff something behind the radiator without removing it but that seems a tad optimistic (and patronising !).  I think I'd suggest the reverse might be more likely !

Exiled_Tyke

I have a bedroom with a bay window. The bay itself is essentially board with a cavity in the middle.  I can't fill the cavity (although I saw a neighbour having this done) as my builder told me it would create damp problems.   Radflek has made a huge difference. I can't of course estimate a cost saving but comfort-wise the radiator is much more effective here.   In another room I put a layer of Kingspan against the bay and then replastered and of course had to move the radiator. The effect here has been phenomenal although I expect it will never pay for itself. 

joefizz

Exiled_Tyke said:

I have a bedroom with a bay window. The bay itself is essentially board with a cavity in the middle.  I can't fill the cavity (although I saw a neighbour having this done) as my builder told me it would create damp problems.   Radflek has made a huge difference. I can't of course estimate a cost saving but comfort-wise the radiator is much more effective here.   In another room I put a layer of Kingspan against the bay and then replastered and of course had to move the radiator. The effect here has been phenomenal although I expect it will never pay for itself. 

Similar story here. 1980s timber framed bungalow with big windows. When redoing the house all the rads were off so I fitted directly to wall behind all the rads (yes easier to fit snugly/completely without rads present). It has made a difference in my circumstances, particularly with the larger 4m wide windows (coupled with 2 layers of thermal blinds).
Was it cost effective? Probably not but taken as a whole seemed well worth doing.

Screwdriva

"Cardew said:...There has been a lot of discussion about these on MSE over the years. IMO and others, they don't save anything at all - others disagree, but nobody can produce test results."

Your request for evidence has been addressed here. It's clear that benefits on uninsulated walls are twice that those for insulated walls, which makes logical sense. That said, most homes have both, making this purchase viable.
My experience is consistent with the above linked study. My wife and I have avoided an under radiated room (small radiator on an external wall). After installation of the reflector, we are able to feel warmth in areas of the room(s) that previous were cold. No doubt in my mind that it's worth the low acquisition price.  

Cardew

Screwdriva said:

"Cardew said:...There has been a lot of discussion about these on MSE over the years. IMO and others, they don't save anything at all - others disagree, but nobody can produce test results."

Your request for evidence has been addressed here. It's clear that benefits on uninsulated walls are twice that those for insulated walls, which makes logical sense. That said, most homes have both, making this purchase viable.
My experience is consistent with the above linked study. My wife and I have avoided an under radiated room (small radiator on an external wall). After installation of the reflector, we are able to feel warmth in areas of the room(s) that previous were cold. No doubt in my mind that it's worth the low acquisition price.  

'It's clear that benefits on uninsulated walls are twice that those for insulated walls,'

Where is that stated in the report? Is there any mention of insulated walls?  The title of the report is heat flow through Un-insulated walls.

Personally I doubt that most homes have both insulated and un-insulated walls.

The revised Energy Saving Trust(EST) at least makes an attempt to quantify financial savings for both uninsulated and insulated walls. - see third post on this thread.

I agree that if you personally benefit from the panel it is certainly worth the modest outlay

Screwdriva

Where is that stated in the report? Is there any mention of insulated walls?  

My apologies, I should have also posted this link, which distills a BRE report. As you can see, comparing the last column to the cavity wall columns immediately next to it highlights a reducing level of effectiveness. That said, even with modern, post 1990 cavity insulation, Radflek does work. 
http://transitionbath.org/technical-analysis-of-radfleks-radiator-reflectors/

By my admittedly conservative calculations, even with a cavity insulated property with 7 radiators, paying 3p per kWh of gas, savings are £5 a year. That's a 5 year ROI on a product stated to last 60 years. 

This seems like a no brainer for anyone with radiators, unless I'm missing something?

Exiled_Tyke

Screwdriva said:

Where is that stated in the report? Is there any mention of insulated walls?  

My apologies, I should have also posted this link, which distills a BRE report. As you can see, comparing the last column to the cavity wall columns immediately next to it highlights a reducing level of effectiveness. That said, even with modern, post 1990 cavity insulation, Radflek does work. 
http://transitionbath.org/technical-analysis-of-radfleks-radiator-reflectors/

By my admittedly conservative calculations, even with a cavity insulated property with 7 radiators, paying 3p per kWh of gas, savings are £5 a year. That's a 5 year ROI on a product stated to last 60 years. 

This seems like a no brainer for anyone with radiators, unless I'm missing something?

So by your figures there is a cost saving, which I'm pleased to see.  I think it's equally important that there's a lot of additional comfort for not a lot of spend - which is exactly what I've experienced. 

Screwdriva

Exiled_Tyke said:

So by your figures there is a cost saving, which I'm pleased to see. 

Correct. Based on your description, you will save/ recover your cost atleast 2X faster than above, given the lack of cavity insulation. My calculation above was intentionally a "worst case" one, assuming cavity filled insulation and low gas costs per kWh. 

Reflectors are one of those "no brainer" additions to any home, like the LED bulb or a renewable energy utility company.