What do people think of this?

Netexporter

You are quite correct @Netexporter.

Thank you. Finally somebody who paid attention, in physics, at school.

MultiFuelBurner

Lol I was saying the same thing a fan will extract heat that needs replacing it won't be free 😘

I think we were arguing the same thing looking back just my bad explanation and those two large rum and cokes.

QrizB

I'm glad we're all back on friendly terms now. It's been like watching two friends argue and risk falling out.

FreeBear

Phones4Chris said:

You are quite correct @Netexporter. If you increase the airflow then the radiator gives out more heat more quickly (and of course the boiler has to replace it) it's the same as effectively increasing the capacity of the radiator. It doesn't matter whether the increased airflow is by convection or by fans, it's just quicker by fans.

Indeed it does. I have a plinth heater with two settings. Normal and boost - The only difference between the two is fan speed, but the heat output is some 30% higher on boost.

See these specs as an example - https://www.myson.co.uk/products/kickspace_hydronic.htm#tab-2

alanwsg

I have a "home-brew" solution using a couple of 12V fans designed to go on your car dashboard, a £3 thermostat off Amazon and an old laptop power supply I had laying around. My first attempt had the fans sitting on top of the radiator but that didn't really work, probably because of the layout of the room. The fans are now at ceiling height and blow the warm air over the refrigerator. 

The difference it makes is astounding. Then fans are over a radiator at one end of the kitchen. The far end of the kitchen was always cold, you needed to wear a fleece at that end. Now it's the first place in the house to warm up.

markin

You can buy a plug with a On temp and Off temp, then you can plug in any 240v fan, For a simpler diy route. Can't use a device with a digital on button.

https://www.amazon.co.uk/Gobesty-Temperature-Controller-Thermostat-Greenhouse/dp/B09JM1G4H6/

M25

LindsayT said:

Wondered if people have seen this and what they think of it?
https://www.highstreettv.com/smartair-boost-2.html

Yes, that'll work but how well? It also conumes electricity. It would also work if you sat next to the radiator and blew air at it.

Those little mechanical fans that sit atop fuel burners work well I've seen them and you can feel the hot air being pushed away from the burner. However there's a lot of spare heat from the burner would that plug in gadget remove so much heat (and steal heat with conduction) that the area next to the radiator would be colder?

I think we'd need a forumite to work out the theoretical radiant heat coefficient. 

Or something like that.

Bendo

I bought a rad fan from Amazon about 3 years ago.  Been sat in the garage for the last 2 as it made no noticeable difference other than noise.

born_again

If these were so good, then radiator manufactures would have been adding them 

Netexporter

Those little mechanical fans that sit atop fuel burners work well I've seen them and you can feel the hot air being pushed away from the burner.

Radiators don't get hot enough to activate the thermal battery. Mine kick in at about 100 degrees C.