I’ve seen quite a few people, and some fan manufacturers, talking about using axial fans (esp PC type) for active radiator ventilation.
I’m wondering about the use of tangential fans, which are, of course, the norm in fancoil emitters, air curtains etc. A priori, they seem to be a better fit to the requirements.
Have any of you folk the benefit of practical experience?
I can’t buy a great value mass produced low noice tangential fan that is easy fit on existing radiators. I can’t see how someone can get the required scale to produce such a product.
So unless Octopus brings out a axial fans that converts 60c flow radators into 50c flow for their Cosy Heatpump at a lower cost then a radator upgrade…
But such a system integrated into their Cosy Hub could be great, giving per room temperature control and recommending radators to rebalance while running the fans to minimise electricity usage taking into effect on flow temperature.
There are some consumer products that sit on top of radiators and blow air out with tangential fans, with RadFan being one brand that seems quite widespread. I’ve not tried one myself.
This is actually a pretty good idea, I was thinking about it too. On average, tangential fans should be quieter than axial ones and create higher pressure (although in this case, I’m not sure if that’s relevant). They will require slightly more space than axial ones (possibly needing to be placed on top) and most likely need some distance on the discharge side to stabilize the vortex flow inside the fan.
I haven’t looked for ready-made solutions and don’t know of any, but as a concept, it’s interesting—you can buy a fan on AliExpress (they come in different lengths) and make the housing yourself.
By the way, I already bought one out of curiosity. It runs on 6-12 volts (BLDC motor), and I can say that it’s still quite noisy for a bedroom, even at low voltage. For other rooms, it might be a viable option.
Do they also come with PWM capability such as axial PC fans? If so, they could interface with my controller. In theory I guess the voltage itself could be PWM driven so there’d be some form of speed control. Is there any way you could test it with a 12V PWM modulated signal?