Fan assisted radiators

[ian192744]

2 minutes ago, SteamyTea said:

Brilliant.

You going to add some monitoring while you are at it?

this answer your question? obviously its all off right now....

 

[SteamyTea]

9 minutes ago, ian192744 said:

this answer your question

Interesting.

Will have to ponder those charts and then see.

 

I still wonder about making my old storage heaters fan assisted.

I like the idea of using magnets to attach things.

[JamesPa]

Thanks for sharing that Ian192744.  I was beginning to wonder about something along similar lines but you have done the hard work.  I need a 30-40% uplift on a couple of difficult radiators to make them practical in size, and I get the impression from what you say this might come close to that, certainly enough to be worth a try particularly given how cheap a 5 pack of fans is. 

ian192744

ian192744

[Ommm]

@ian192744 Your setup's really interesting - I hadn't realised computer fans were so cheap (I'm used to buying the full CPU cooler).  The Arctic fans are about £4-5 each which makes it cost effective to fit loads of them.

 

I bought a couple to try out: the non-PWM versions of the Arctic F8 and the Arctic P8 (my rads are 60mm deep so need to stay small).  At full 12V power the background sound with the fan off was about 29-30dBA at 1 metre and with the fan on 32-33dBA.  That's just holding the fan in my hand and pointing the airflow towards my phone measuring sound.  I couldn't measure a difference between the two models on the phone, but when holding them the P8 sounded slightly louder.  Each fan took about 0.09A at 12V, so about 1.1W.

 

So those are much better sound wise than the 4YourHome unit.  I haven't compared them for airflow yet: I suspect I'd need several fans to equal the output of the 4YH (which has no specs for air volume, but is rated at 12W) - the F8 claims 52.7m3/hr at 2000rpm, the P8 claims 40.3m3/hr at 3000rpm with higher static pressure (which it was not experiencing in my test). 

 

For cooling I'll have to consider the mounting.  I'll have to mount them on the top of the rad so there's space for condensate collection at the bottom (gutter and water bottle?).  Maybe it makes sense for them to blow cold air up, to encourage room air to mix and warm air to come in underneath (fighting convection).  Or maybe a room fan is needed to destratify the room.  Things to ponder...

[Wil]

I think a lot of the noise in my 4YourHome unit is to do with the mounting and vibration rather than airflow. I'd be interested if Ian's solution with the magnets held strong enough or if some rubber gaskets were needed to try and prevent too much vibration.

 

On the mounting I was thinking of the fans being at the top but angled at 45degrees pointing up and out to the room to try and throw some air as opposed to just a straight throw. This goes back to some kind of enclosure around the fans and rad to hide all the ugliness anyway.

[Ommm]

I suspect the 4YH noise is due to the aluminium crossflow fan barrel spreading out as it spins due to centifugal force, which then sets a resonance up against the plastic casing.  It only seems to be at particular speeds (which includes both of the speed settings).  I'm going to send it back, otherwise I would take it apart to investigate.

 

45 degrees is a good thought - would stop it interfering with curtains etc over the radiator.  I did wonder about 80mm guttering for that (in white):

https://www.floplast.co.uk/product/offset-bend-3

 

although probably a trough style arrangement a bit like the 4YH case but wider would be better.  Might be possible to make something neat with white uPVC sheet eg fascia board, perhaps on a wooden frame.  Or possibly large-section electrical trunking (also uPVC).

Edited May 27, 2022 by Ommm

[ian192744]

On 27/05/2022 at 09:35, Wil said:

I think a lot of the noise in my 4YourHome unit is to do with the mounting and vibration rather than airflow. I'd be interested if Ian's solution with the magnets held strong enough or if some rubber gaskets were needed to try and prevent too much vibration.

 

On the mounting I was thinking of the fans being at the top but angled at 45degrees pointing up and out to the room to try and throw some air as opposed to just a straight throw. This goes back to some kind of enclosure around the fans and rad to hide all the ugliness anyway.

 

there's absolutely no vibration. I bought a 100pack of these guys https://www.ebay.co.uk/itm/144017582577, as long as the rad is the right shape to get a good contact, they won't move. PWM allows you complete flexibility with fan speed if you're unlucky enough to find a resonance at some point. But a bit of neoprene superglued around the contact points would be easy peasy to add if vibration damping was needed.

 

I used to have a bit of an obsession with SilentPC's, I'd always build my own in the days when aircooling was the only option. I now buy fully passive heatpipe+heatsink and/or All-in-One water coolers for PC's that I uses, but its given me the background on building for airflow and near-silence at the same time. Mid-spec PC fans are really quiet and don't cost the earth.   The arctic PWM PST fans are so useful because they come with the daisy chain connectors as part of the design - so only one upstream connection for as many fans as you like.

 

I was thinking about top vs bottom of rad as mount point for cooling as well, although I don't have a cooling capable source yet. One bonus of magnet-held setups is that you do have the option to simply move it from the top of the rad to the bottom or vice versa.

 

rads with less than 80mm depth are indeed a problem. depending on what else is below the rad you could mount an 80mm fan on an angle (lower end toward the wall, some trickery with clips into the skirting to hold that side up).  I tried this with a K1 rad and it was ok but not great, obviously significant airflow wasted going behind the rad into the unheated space. I didn't experiment with blocking it. unfortunately I haven't found any 60mm fans worth trying - of course they exist, but they are all designed for comms room / datacentre environments where low noise is not a thing - plus to cover the length of the rad, you need loads. I think 80mm is the smallest worthwhile.

 

I think something like this https://www.amazon.co.uk/Myhomeware-Radiator-Adapter-Diverter-Booster/dp/B07LGCXQZV?th=1 should be easy enough to make , in order to divert air away from curtains at the top,  and if reversed with fans blowing down from the top and mounted underneath, could probably form the basis of a condensation drip catcher for cooling. I haven't done anything about that yet though.

 

the other thing to think about is that if you CAN fit a K3 rad in for depth, then you'd have space to use 140mm fans which will have loads more airflow and you need less to cover the length - you  could then make the rad smaller in either height or length. basically I am trying to avoid having to replace all my rads, especially not put monster K3's  in everywhere. I'd rather have a K2 with a fan. 

 

having looked at the design of some of the commercially available FCU's , I couldn't find any where I liked the way they worked (fans too small, not controllable enough, no noise specs on the actual fans themselves - only on the overall unit) and/or pricing levels are very high compared to that of a rad plus some fans. And being a bit of a tinkerer I thought I'd build my own!

 

I'll be building the mk2 at some point soon, I'll take some more detailed pics.

 

Ian

 

 

[JamesPa]

It would be good to know how much extra output fans produce from existing radiators.  I think it should be possible to work out a %age increase by measuring the change in deltaT -  can anyone see a better way (or any flaw in this)?

 

I've just bought some bits to play including this https://www.ebay.co.uk/itm/254722117981 controller which I think combines the low temp shutdown function with the speed control.  I will report back on the latter.

[JamesPa]

On 28/05/2022 at 20:48, JamesPa said:

It would be good to know how much extra output fans produce from existing radiators.  I think it should be possible to work out a %age increase by measuring the change in deltaT -  can anyone see a better way (or any flaw in this)?

 

I've just bought some bits to play including this https://www.ebay.co.uk/itm/254722117981 controller which I think combines the low temp shutdown function with the speed control.  I will report back on the latter.

 

Postscript: https://www.ebay.co.uk/itm/254722117981 , also known as a 'fan 1248', seems to work well and comes complete with a temperature sensor, but you still need a 12V relay to shut the fan off completely.  Contacts for the 12V relay are provided. 

 

Without a relay it turns the fan down very low at the programmed 'shut off' temperature, but not quite off.   With one fan turned down to minimum the board plus fan draws 70mA at 12V, if I disconnect the fan it is 65mA, so the 'slow running' fan is drawing just 5mA=60mW and the board itself 65mA=0.8W.  At this level Im not sure a relay is worth the bother, probably best just to leave the whole thing on and turn it off at the end of the heating season!

 

The onboard fan connector is not conventional, but I eventually tracked it down - its a JST VH 3.96.

 

Its currently too warm to try the fans on radiators, and anyway my central heating is drained down while I upgrade the rads in preparation for eventual fitting of an ASHP.

Edited July 24, 2022 by JamesPa

[offthepiste]

We are fitting JAG radiators as part of our retrofit. I have deliberately selected slightly lower output models, i.e. depth and width (height whilst affecting output has less of an impact) referring manufacturers tables.

 

I know how we lived in our very drafty victorian house with its relatively cool radiators. So given our Enerphit'ish retrofit am betting on requiring less energy than per the calculations.

 

However, as an insurance policy have selected the slightly deeper, starting at 115mm I think, for some rooms so I can fit the JAG fan solution. Assuming they are accurate it is slightly gobsmacking to see what a positive difference they would make should we feel too cold.

 

Obviously am having power supplied to each rad where fans may be required.

 

Wet UFH throughout the GF and rads on the uppers, Viessman split ASHP.

[offthepiste]

Did also find a hack for building your own fan unit on a German website but the cost was not too far off the JAG units.

 

[Wil]

2 hours ago, offthepiste said:

We are fitting JAG radiators as part of our retrofit. I have deliberately selected slightly lower output models, i.e. depth and width (height whilst affecting output has less of an impact) referring manufacturers tables.

 

I know how we lived in our very drafty victorian house with its relatively cool radiators. So given our Enerphit'ish retrofit am betting on requiring less energy than per the calculations.

 

However, as an insurance policy have selected the slightly deeper, starting at 115mm I think, for some rooms so I can fit the JAG fan solution. Assuming they are accurate it is slightly gobsmacking to see what a positive difference they would make should we feel too cold.

 

Obviously am having power supplied to each rad where fans may be required.

 

Wet UFH throughout the GF and rads on the uppers, Viessman split ASHP.

Do you have a link to some information. Google brings me an awful lot of car rads but no JAG ones...

[offthepiste]

@Wil apologies just spotted your question - its jaga - my mistake. These are the ones we are going for, cheers

 

https://jaga.co.uk/wall-mounted/strada

 

[JamesPa]

Thanks for this.  Judging by the brochure the Jaga rads are interesting in themselves, but also as a case study. 

 

From the brochure it appears that the Jaga Strada 'Dynamic Boost Hybrid' radiator is a standard Strada radiator with a bunch of computer fans on top of the radiating element.  The fans, if not operational, appear to reduce the output by about 30% (its not clear whether this is because they interrupt the convection or because the space taken up by the fans reduces the radiating area available within the casing) but if operating increase the output by 40%-80% (compared to the fanless version) dependent on speed (see the table extract below which is from the Jaga website for a 45/35 flow/return temps.  They are also advertised for what they call 'light cooling' - by which they mean cooling where the flow temp is kept above the dew point.

 

The rads themselves are a low water content design.  Its plausible that this increases the effectiveness of the fan relative to doing the same on a conventional radiator, because of all the fins, but still suggests that adding the idea of adding computer fans to a standard radiator is likely to give a meaningful increase in output.  

 

 

 

 

 

 

 

[offthepiste]

@JamesPa Yes, they are interesting. The quoted electricity requirements for the fans appears minuscule. 

 

We are provisioning electric points in case we need to fit the fans. I have slightly undercooked the radiator output as I know what our old radiators put out with our very drafty victorian terrace in our upstairs rooms - obviously benefiting from convected heat. So bit of an insurance policy.

[Rich210]

My house has a mixture of K2 and K1 rads. The majority are K1 rads so I bought 3 double sets of the speed-comforts. I know they're fairly expensive, but I wanted a fairly hassle free solution to improving the comfort in the house and with gas prices high, I rationalised them as an investment. 

 

Subsequently I bought 8 80mm fans off ebay along with a 12v controller. I'm effectively using the speedcomfort's for the plug initial fans and control mechanism for turning the fans on and off. Probably an expensive way of doing it! But, I'm making savings on the ebay 80mm fans and I'm arranging them like Ian using the the magnets. Originally I thought of getting the craft glue gun out and just sticking them to the underside.

 

I like the look of the artic fans, and I think for simplicity, I'd go with those next time. 

 

I was interested in finding out how these perform with ashp. I understand that ashp don't like a big flow and return temp difference, and obviously the fans increase the temp difference which is really helpful for combi boilers. 

 

 

 

[ReedRichards]

8 hours ago, Rich210 said:

 I bought 3 double sets of the speed-comforts. I know they're fairly expensive, but I wanted a fairly hassle free solution to improving the comfort in the house and with gas prices high, I rationalised them as an investment. 

 

 

Fans enable you to get more heat out of a radiator of a given size.  But this is not "free" heat, your boiler or heat pump will have to work harder to supply it.  As gas prices are high, this extra heat will be more costly than it used to be.  

Edited September 12, 2022 by ReedRichards

[Rich210]

18 hours ago, ReedRichards said:

 

Fans enable you to get more heat out of a radiator of a given size.  But this is not "free" heat, your boiler or heat pump will have to work harder to supply it.  As gas prices are high, this extra heat will be more costly than it used to be.  

But the boiler will make use of condensing efficiencies, so that is free heat I wouldn't have had before. 

 

There was a bit of a chill last night so I had a go in our large living room with a t22 rad that always been undersized. Running the rads at 33'c flow my partner was impressed. The rad also needed bleeding so the fans were working on a defunct rad. 

 

On the boiler working harder, my boiler is a crap baxi 830 boiler that won't modulate below 6kw. Rough calculations suggest 7.5kw would heat my home at -2'c. I have no worries about making the boiler work harder it's already massively oversized and poorly designed. I'm much more interested in lower flow and return temps so when it does fire up its making best use of the gas.  Hopefully I'll get it replaced with a ashp within the next couple of years.  

 

This winter is going to be an experiment to see how much I can get out of what I've got. The fans are a cost effective way of theoretically increasing the size of rads without installing new radiators everywhere. This is a desirable thing to do to improve heating efficiency. 

 

I'm presuming people adding radiator fans to combi boiler domestic central heating system rads are doing it for the same reasons.

 

If you're unsure about how combi boilers work google combi boiler efficiency and you'll see a graph that's very clear and easy to understand.

 

 

 

 

[ReedRichards]

3 hours ago, Rich210 said:

The fans are a cost effective way of theoretically increasing the size of rads without installing new radiators everywhere. This is a desirable thing to do to improve heating efficiency. 

 

I'm presuming people adding radiator fans to combi boiler domestic central heating system rads are doing it for the same reasons.

 

 

I concur that adding fans to existing radiators may well be a more efficient way of boosting the heat output to your house than the alternative of turning up the maximum temperature on your gas boiler so the radiators run hotter.

[Archer]

On 27/07/2022 at 13:24, offthepiste said:

We are fitting JAG radiators as part of our retrofit. I have deliberately selected slightly lower output models, i.e. depth and width (height whilst affecting output has less of an impact) referring manufacturers tables.

 

I know how we lived in our very drafty victorian house with its relatively cool radiators. So given our Enerphit'ish retrofit am betting on requiring less energy than per the calculations.

 

However, as an insurance policy have selected the slightly deeper, starting at 115mm I think, for some rooms so I can fit the JAG fan solution. Assuming they are accurate it is slightly gobsmacking to see what a positive difference they would make should we feel too cold.

 

Obviously am having power supplied to each rad where fans may be required.

 

Wet UFH throughout the GF and rads on the uppers, Viessman split ASHP.

Hello, sorry to jump on this thread, but interested in the Jaga radiators and wondered if you can provide a quick update now that they are installed?

 

It seems that you can size them similar to conventional rads if replacing a gas boiler system with a low temp ashp... The "light cooling" function is also very interesting. 

 

Any advice on what Jaga are like to deal with, UK suppliers and product warranties, how noisy / effective they are in use and also whether the cooling works in a meaningful way? It looks like a very good product, any feedback appreciated. Cheers

Edited October 10, 2022 by Archer

[offthepiste]

Hi @Archer they are not fitted yet, will give you an update once they are fired up. The retrofit is being done as a turn key project by a main contractor. But wil try to get detail on dealing with Jaga.

 

We are not using them in cooling mode as this will be handled by Zehder MVHR.

 

cheers 

Edited October 11, 2022 by offthepiste

[BenY]

I have used iVector MkII fan assisted radiators on my project.  The quotes for these were cheaper than the Jaga ones.  I ordered them without any controls and they have a built in transformer which also saved some money.  They are controlled on a 0-10v input for the fan.  They are still not cheap though at around £650+ for each.  So far they have worked well for both cooling and heating.  I was doing a full retrofit so I have added dedicate condensate pipes for the cooling.  The fan is basically silent up to 20%, tolerable up to 50% and then gets pretty annoying after 80%.  This is based on sitting about 1m away from the one in my study,  

 

https://www.myson.co.uk/products/iVector_MKII.htm

 

Bought them here.  From memory about 4 week lead time.

https://www.mytub.co.uk/600x800-myson-ivector-mkii-f-convector-2-no-btm-tp-product-766077

 

Regards

[JohnMo]

3 hours ago, BenY said:

still not cheap though at around £650+ for each.

Wow that's a2a heat pump costs?

[Archer]

On 11/10/2022 at 14:53, offthepiste said:

Hi @Archer they are not fitted yet, will give you an update once they are fired up. The retrofit is being done as a turn key project by a main contractor. But wil try to get detail on dealing with Jaga.

 

We are not using them in cooling mode as this will be handled by Zehder MVHR.

 

cheers 

Thanks, that would be awesome. 

 

I'm trying to get my head around the "light cooling" idea, and how meaningful this would be in practice. From reading the Jaga literature they output significantly less in cooling than heating mode anyway, which means you'd probably need to oversize the rad's to really benefit. This could be worth doing anyway, because the fan at max "boost" speed is really noisy - nearly 50db - so avoiding the need to use this setting for long would be beneficial. 

 

Jaga seem to think you can get (up to) around 3 or 4 degrees of cooling from the light cooling function, running water chilled to 16 degrees without it condensing. I haven't spoken to them yet but it's not entirely clear what's special about the system that couldn't be replicated in a DIY route as others have posted above. I did read somewhere about an optional temperature/humidity sensor that you can purchase as an add-on, but the rad's with the DBH module (ie computer fans) are already seriously expensive. 

 

It might be cheaper to get a unit with a condensate pipe and tray but it's hard to know how often you would need to empty them 

Edited October 22, 2022 by Archer

[SteamyTea]

21 minutes ago, Archer said:

Jaga seem to think you can get (up to) around 3 or 4 degrees of cooling from the light cooling function, running water chilled to 16 degrees without it condensing.

Only got to run the numbers though a Dew Point calculator.

Air at 23°C and 65% RH has a dew point of 16.1°C.

13g/m³ of water in it.