I’m thinking about adding fans to a couple of radiators that are a little bit underpowered with my ASHP. Does anyone have experience with speedcomfort or similar, do they work?
Thanks
Andy
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I recently bought two radiator fans to cool their rooms by drawing cooler floor air though the cool radiator and into the room. For 1 Watt they are very efficient. I’m hoping to use them with the heating on, but not quite yet.
Radfan are launching a heat pump version of their fans at the end of the year with more fans to draw heat from the relatively cooler radiators. More fans also means more noise. A problem with the current radfans is that they only switch on when the embedded thermostat reaches 30 °C and the cooler radiators will take longer to achieve that. It’s to do with the temperature differential between the radiator and the deeply embedded thermostat.
Hi not that you have a “dirty house” but there can be a buildup of dust on the radiators fins.
Use a thin duster and vacuum, it may suprise you how much is hiding.
It will get the radiators up to full efficiency.
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I dust my radiators a few times a year and a lot of stuff comes out, including toy cars.
The other day when I was deep cleaning a wet room it suddenly occurred to me to hose down the radiator. Oh boy, the amount of fluff and dust that got flushed out was amazing.
I bought speedcomfort fans. I will test this in one bedroom to compare with the other and feedback in the winter.
I did test them and they seemed quieter than I expected. As they will be at the end of my bed (head end) and I am a light sleeper we will see how it goes.
Similar to Andrew I have a heat pump and one radiator is underpowered. Due to space constraints I can’t upgrade the radiator. I bought a SpeedComfort and its very easy to fit but it doesn’t goes on until it sense the radiator at 35C. Due to my compensation curve, which is determined by the rads in the other rooms, its only in the coldest weather that the rads reach 35C.
Is there a way to adjust the thermostat in the SpeedComfort?
Or is there another system which can be controlled differently and activated at lower radiator temperatures?
Does the unit have an always on setting for summer cooling? If so that would enable external control by a timer or thermostat.
The fans work well and as the rad is behind my bed it is quiet enough for me as a light sleeper.
I’m not aware of any adjustments on the thermostat other than trying to move the sensor to the warmest part of the rad.
My flow temperature is higher than 34c so this has not been an issue for me.
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My new heat pump is struggling to keep the loft conversion warm at the
moment, despite putting in a larger radiator. It struggled a bit when temperatures dropped below zero last month, but struggled even more in the wind on Saturday.
The installer is wondering whether an even bigger radiator in the loft is
needed - he acknowledges that the modelling used for heat loss
calculations hasn’t reflected reality. The lockshield is fully open, so we’re not going to get any more heat out of it.
I was wondering whether a radiator fan would be helpful in moving what heat the radiator is emitting from the radiator under a window into what is quite a big room. The Speed Comfort sound good but the triple is recommended for the 1600x600 radiator, and it’s a bit pricey for an experiment.
My flow temp has been between 30 and 35 through November, apart from the really cold few days, so also wondering whether the thermostat can be adjusted to start up the fan at lower temperatures?
30-35 flow temp is quite low. If this keeps the remainder of your house warm then it’s no problem. If this is the case it seems like your radiator in the loft is too small. You can either reduce heatloss or add more heating capacity. I have a radiator fan, it helps a little, but doesn’t make a huge difference.
As your loft is the highest point, you can check that the radiator does not need bleeding. Also, is there sufficient pressure to feed the higher radiator? Have you balanced the other radiators, this would help feed the higher radiator.
Regards
Andy
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As Andy says, by reducing flow to the other radiators you may be able to increase flow to the loft room. Try bleeding all radiators, as gas trapped elsewhere in the system can restrict flow.
Loft rooms are notoriously difficult to insulate and make airtight, particularly those with dormer windows, so heat loss may be much higher than calculations have suggested. Airtightness may well be a major issue, since you mention being cold during the storms. My whole house temperature dropped during the extra windy weather, probably for the same reason.
If you do go for a radiator fan consider triggering it from the circulating pump rather than a thermostat. Either wire it into the same circuit or use a smart link.
30-35°C seems reasonable.
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Thanks Andrew.
This is my first winter with the heat pump. Heat loss calculations assumed that the ground floor would be insulated, and airtightness measures carried out. But as I’ve mentioned elsewhere that still hasn’t happened for a number of reasons. So heatloss reduction in progress!
Once that happens we (the hp installer and myself) will need to rebalance radiators throughout again.
In the interim the radiators have been balanced (I have IMI bi-directional combined thermostatic radiator valve and lockshield), and the lockshield on the loft radiator has been opened up completely, and others adjusted up or down to provide comfort on first floor, while leaving the TRV element fully open. Throughout October and early November all was well.
I believe there is sufficient pressure to feed the higher radiator.
The Open Energy Monitor heat pump monitoring kit is still occasionally reporting errors in the heat meter monitoring due to air in the system, so I am bleeding the loft radiator at least once a week. I’ve checked all the others two or three times over the last couple of months and found no air in them. No air came out of the loft radiator yesterday.
Thanks Tim,
I think the hp installer has done as good a job as possible in balancing the radiators, while the ground floor remains less well insulated than it was before the heat pump installed.
Regular bleeding of loft radiator has finally got rid of most of the air in the system.
While I agree that I will need to tackle insulation and airtightness in the loft at some time, it won’t be happening soon.
Someone else who uses a fan radiator has told me that “the in built temperature sensor is set to 35⁰C. So I set them to continuous running (ie I’ve disconnected the sensor from the device) and instead use a home assistant automation and a smart plug to turn them on when the heat pump is running.” Am I right in thinking that the end result is what you are suggesting?
For the rare occasions when family or friends are staying in the loft, I can just use some kind of direct heating.
And I do have the option of changing the loft radiator for a bigger one, which may be the best long term solution.
The more I think about it the less certain I am that the cost of a triple fan (for a 1600x600 radiator), and trying to bypass the sensor, is worthwhile.
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Yes.
I agree that if space permits, a triple radiator is better value than a triple fan! Radiators, being passive, are far less prone to faults and have a lower running cost. If you can find a use for the one you remove then all the better. With a heat pump you cannot have too many radiators, particularly low down in the building*. If the building then gets too hot or thermostatic valves close then reduce the flow temperature, which increases the COP.
*Low down because warm air rises. Upstairs radiators only heat upstairs. Downstairs radiators heat the whole house. (Once your floor is fixed!)
Incidentally, the flow and return to your DHW cylinder/store should be insulated but, in an insulated house, the ones to your radiators should not, as they contribute to the thermal exchange surface area. Any pipework that is part of both should be insulated. By insulation I mean good thick insulation, not the pathetic membrane that my plumber seems to prefer.
Hi Sian,
I think you may have need of the IR camera to identify problem areas - radiator, draughts and cold spot identification.
Hi Sian,
Yes the Speedcomfort fans work really quire well, with the caveat that for a heat pump you may need to devise your own fan automation as the on-board temperature sensor may not be triggered by radiators operating at ~30-35C.
Clearly if you have the option of upgrading the radiator itself fairly easily then that will definitely be a worthwhile upgrade. Also factoring in the cost of the Speedcomfort fans themselves also means that cost of a radiator upgrade can be offset against the purchase cost of the fans.
The air-leakage heat losses will also be worth investigating and if possible further air-tightness measures will also be very worthwhile.