Current draw of radiator fans?

[Harnser]

I'm planning to repurpose a dual fan radiator cooler as a high-volume fan and can't find any numbers for what current they draw. I know they are 12V so am thinking a laptop PSU can power it, but will it provide enough amps?

 

[Rroff]

Wrong forum section I think.

Average PC fan is usually rated between 0.2 and 0.8 amp 12V though they'll often draw a bit lower than that in normal use.

 

[sovietspybob]

i think they are usually quite high power, like can be 200+watts per fan kind of power if you're talking about a car radiator fan.

So you're looking at needing a 20+ amp power supply to not be running it at the limit, not really ideal. Best off getting something that's 240volts out of the box.

 

[DRZ]

10A for a weedy one, 20A+ for a "proper" radiator fan if you're talking about cars... They draw quite a bit more than that when spinning up too, so bear that in mind.

 

[Harnser]

Yes car radiator fans lol. I want to build one of these to find the remaining air leaks in my house https://renewableheatinghub.co.uk/forums/insulation/diy-blower-door-testing and everyone talks about car radiator fans without saying about the power source. Guess a car battery is going to be the best option, and forget about speed control?

Best off getting something that's 240volts out of the box.

240V fans that have the same CFM as a 12V fan are much more expensive which is not what I expected. It would be much easier though

 

[Rroff]

If car radiator fan they can easily pull 25+ amps in-rush or if not functioning properly so you'd want a power supply capable of handling that - while they can be as low as 10 amp in normal use. Could wire one off an old PSU using the "paperclip" trick to power up - but you'd have to look at the rail specifications - some are specced for 25amp some only like 18, etc.

 

[Diddums]

Careful with this, you're effectively sealing off all the ventilation in your house. It might not be intentional ventilation, but removing it without carrying out the correct checks means that your house could well become a nightmare to maintain in terms of damp and mold.

For extra resources, search "room integrity testing" - this is more for fire suppression systems but it's the same principle and you'll likely find a ton of useful info.

We use these when we do it:

Error 410 | Screwfix

Thousands of products at low trade prices | FREE next day delivery available | 30 day money back guarantee on all orders.

www.screwfix.com

These make a lot of smoke though, so keep that in mind. We've had the fire brigade knocking on doors a few times.

 

[Harnser]

Careful with this, you're effectively sealing off all the ventilation in your house. It might not be intentional ventilation, but removing it without carrying out the correct checks means that your house could well become a nightmare to maintain in terms of damp and mold.

I can't wait to need to add back ventilation! At the moment close any internal door and there's a steady draught under it, which changes depending how windy it is outside. And this is after filling in the random holes into the cavity/vented floor that don't align with an airbrick. What's left seems to be a lot of tiny holes, and only findable in high wind conditions. Which I hope to replicate with the blower door.

For extra resources, search "room integrity testing" - this is more for fire suppression systems but it's the same principle and you'll likely find a ton of useful info.

Thanks that's a search term I didn't know.

I've tried joss sticks for smoke which don't make enough; those smoke pellets might make a little too much

 

[Diddums]

I've tried joss sticks for smoke which don't make enough; those smoke pellets might make a little too much

H'ctually I've just seen that those are 5g, ours are 13g so almost triple the smoke. Might be worth a look.

I'll have a rummage tomorrow, see if we've got any spares. Not sure what RM will think of me posting them mind