Radiator Booster - any thoughts?

zeupater

doughnutmachine wrote: »

would this 15w fan not provide heat to the room as well....

Hi

There is no 15W fan .... it's just a case that if you wanted to completely prevent the 45W of gas provided heatloss from behind the radiator (which you raised) with an electric fan (which you probably can't), using an energy source which costs three times more (ratio 3:1), then you have an energy breakeven point of 1/3 of 45W, hence the original post included ".... therefore with a cost ratio of approx 3:1 you would be losing out if providing anywhere over 15W of forced airflow" .... you raised added complexity regarding the heat provided by the fan which was addressed in detail within the previous post, it is also already included in the referenced calculation .... (((45x3)-(45x1)-(45x0.5x1))/(45x1)) ....

As previously stated, it's all irrelevant as the boosters on question are rated at ~1.2W.

HTH
Z

doughnutmachine

zeupater wrote: »

you raised added complexity regarding the heat provided by the fan

got there eventually

janaltus

zeupater wrote: »

Whatever size fan would be required makes little difference, it seems to be a ~1.2W DC fan which the boosters have and as previously intimated, a fan of that size would be totally overwhelmed by the natural convection .... it would be pretty logical to conclude that obstructing the airflow behind a radiator would actually increase the temperature of the wall and thus increase the immediate area through-wall heatloss ....

HTH
Z

I was away on holiday when my plumber fitted a radiator for me. Unbeknown to me, and to my horror, he fitted the rad on an external wall and under a window - in the very large cold attic bedroom at the top of my house. Despite having a recently fitted modern condensing gas-fired combi-boiler - and the radiator getting quite hot, the room rarely gets pleasantly warm.

Obviously the rad needs resiting but until then ... I bought a Radiator Booster Mk 3 to see if I could improve heat circulation in the room. I had no concerns about extracting heat from the rad as it is the last one on the loop. I assumed any obstruction of the rad from releasing convected heat directly upwards would not be a bad thing as there was a single-glazed sash window directly above the rad.

However, I was immediately struck by how little air output there was from the so-called Booster. I had no more technical equipment available than the back of my hand, a piece of tissue paper and a £5 note. But I placed each above the radiator, above the Booster and, to the side, to the single output port of the Booster.

I found the unimpeded output of warm air from the radiator was significantly higher than the output of the Booster (and, obviously, higher than the output of the radiator where it had been obstructed by the Booster).

I later measured the room temperature, over a period of ten days, comparing external temperatures, and found that the average temperature in the room remained at a pretty constant 18 degrees C, whether the Radiator Booster was on or off.

It struck me that the booster fan would be better employed if it was placed underneath the radiator (as long as it was placed in such a position that it did not actually impede air flow).


The Booster came in a long cardboard box which I have not yet sent for recycling. I am in a dilemma:

• do I extract the fan from the Booster and fit it in the cardboard box, so I can build a long booster that provides a below-the-rad improved airflow?
• do I glue foil to the cardboard and slip it behind the rad to lower heat loss into the external wall?
• do I use the cardboard plus drawing pins to help insulate the sash window for the Winter months?

Whatever I do, I suspect, like many children over the festive season, I will get more value-for-money out of the cardboard box that the Radiator Booster came in, rather than the expensive gadget itself.
:doh:

Mayen

Thankyou to the various for the technical explanations as to why they think these devices shouldn't work, I'm sure that had I the modern rad's they refer to I would not have needed to boost my rads performance

However with old un-finned rads adding side mounted units blowing into the rads there is an immediate noticeable increase in the heat output just above the rad & temperature measurements show room temperature increases (to levels not previously achievable).

Perhaps a discussion on under what circumstance this method will help given specifics to use against those where its use would likely be of little or no benefit would be more constructive.

Mayen

I now have my first months results after starting using my own custom radiator assistors.

Abient tempretures in the region dropped by 1.7°C November to December and despite that my units enabled an increase in room temperature of 2°C+ yet at the same time my gas usage for the month dropped by 3.3%. I put the saving down to:

A: The boiler temperature reduction these allowed.
B: Its possible my condensing boiler is now able to work in condensing mode making it more efficient.

I must add my experiments have led me to believe (as ascertained by other posters) placing any units on top of the rad will be in part (or totally) counter-productive as it will block natural convection. All my units are side mounted.

arasca

I have purchased the radiator booster few weeks ago from amazon.co.uk unfortunately the item is not what i was looking for, it is not boosting at all, it is noisy and blowing the cold air instead of how air, i guess it is good for small radiators, it is also stopped working and send it for a refund, then i came cross the fallowing items amazon.co.uk/Radiator-Adapter-Diverter-Booster-1300mm/dp/B00BJLWL9C/ref=sr_1_23?ie=UTF8&qid=1361874127&sr=8-23 purchased only one to see the affects, and it works like a charm, it does not need any cable and looks fantastic, you can feel the warm air coming out of the radiator and diverting that hot air in to your room, now i have ordered the other size for my radiators

hope this will help as you know these days the bills are up on the roof

Martyn1981

arasca wrote: »

hope this will help as you know these days the bills are up on the roof

Hiya, I can imagine this working quite well, by making you feel warmer, even if the room hasn't heated up yet. Having fitted a shelf over the kitchen radiator (about 100mm above) I'm still getting caught out when I walk past and it feels like a hot air blower is being directed at me.

But ..... £20 for a 400mm model seems pretty high. I'm sure I only paid £15 for the 'floating' shelf kit, and that was 1200mm.

Nothing against the product, but if there is room for a DIY option, such as a shelf, then the cost may be a lot less, and at the end of the day - you've got a shelf!!

Mart.

grahamc2003

Mayen wrote: »

Thankyou to the various for the technical explanations as to why they think these devices shouldn't work, I'm sure that had I the modern rad's they refer to I would not have needed to boost my rads performance

However with old un-finned rads adding side mounted units blowing into the rads there is an immediate noticeable increase in the heat output just above the rad & temperature measurements show room temperature increases (to levels not previously achievable).

Perhaps a discussion on under what circumstance this method will help given specifics to use against those where its use would likely be of little or no benefit would be more constructive.

It's pretty straightforward what these things can and can't do. The fans mean the radiator operates under forced convection instead of natural convection. So the convective heat output from the radiator will rise. The surface temperature will lower, so the radiative heat output will be lower. The ratio of radiative to convective heat loss means that it's likely thast the overall heat output will increase a small amount. The heat available for radiators downstream will lower, so their output will decrease. The water return temperature to the boiler will probably be a tiny fraction lower, so it is likely to increase the overall efficiency by a tiny fraction (but will be unmeasurable without specialist equipment, and the difference in monthly bill will be pennies, not pounds, all other things being equal). Your testing is meaningless, because you can't keep all other things equal over the tests. The effect you are reporting is due to a combination of variation in parameters over the tests, and a natural bias to reflect your pre-existing view, and other psychological factors.

Martyn1981

grahamc2003 wrote: »

The heat available for radiators downstream will lower, so their output will decrease.

Why would the heat available 'downstream' be lower? The outlet from each radiator should be plumbed into the return flow shouldn't it?

Mart.

jamesd

The downstream would be receiving cooler water because the upstream radiator would have removed more heat from it.