Fans- Suck or Blow?
Fans- Suck or Blow?
Author
Discussion

Craighb

Original Poster:

266 posts

196 months

Thursday 5th May 2011
quotequote all
I know ive read this in a recent post but cant find it using my iPhone in the garage!

Just fitted a Pro-Alloy rad and run the car up to temp. when the fans cut in they were blowing air out of the front of the car. Surely they should be drawing air through the rad and out of the top of the clam.

Can someone confirm.

Thanks.;

mgbond

6,749 posts

261 months

Thursday 5th May 2011
quotequote all
Craighb said:
I know ive read this in a recent post but cant find it using my iPhone in the garage!

Just fitted a Pro-Alloy rad and run the car up to temp. when the fans cut in they were blowing air out of the front of the car. Surely they should be drawing air through the rad and out of the top of the clam.

Can someone confirm.

Thanks.;
They blow onto the rad from the cockpit side so yes it will come out the front.

Bondy

AverageMPH

493 posts

191 months

Thursday 5th May 2011
quotequote all
mgbond said:
Craighb said:
I know ive read this in a recent post but cant find it using my iPhone in the garage!

Just fitted a Pro-Alloy rad and run the car up to temp. when the fans cut in they were blowing air out of the front of the car. Surely they should be drawing air through the rad and out of the top of the clam.

Can someone confirm.

Thanks.;
They blow onto the rad from the cockpit side so yes it will come out the front.

Bondy
Mine draw air through the rad, drawing from the front and out through the top of the clam.

Craighb

Original Poster:

266 posts

196 months

Thursday 5th May 2011
quotequote all
Oooooh K. Unfortunately, thats not what i'd call a concensus! Now I'm confused- logic would dictate that the fans draw cold air through the rad assisted by the forward movement of the car. If they blew air from back to the front wouldnt the airflow just be cancelled out?

rb5230

11,657 posts

201 months

Thursday 5th May 2011
quotequote all
Craighb said:
Oooooh K. Unfortunately, thats not what i'd call a concensus! Now I'm confused- logic would dictate that the fans draw cold air through the rad assisted by the forward movement of the car. If they blew air from back to the front wouldnt the airflow just be cancelled out?
Makes sense to me too.

AverageMPH

493 posts

191 months

Thursday 5th May 2011
quotequote all
rb5230 said:
Craighb said:
Oooooh K. Unfortunately, thats not what i'd call a concensus! Now I'm confused- logic would dictate that the fans draw cold air through the rad assisted by the forward movement of the car. If they blew air from back to the front wouldnt the airflow just be cancelled out?
Makes sense to me too.
Thats what mine does, which makes sense to me too.

mgbond

6,749 posts

261 months

Thursday 5th May 2011
quotequote all
Fans wouldn't be running when the car is driving as this would cool the rad anyway. The way to think about it is as follows:

Noble added a shroud so when the fans blew it forced the air all over the rad rather than straight through in small areas. Not sure it would suck as efficiently.

I may well be wrong as you can feel lots of air coming out from the top of the clam. Just thought it was the air reflecting back that didn't blow through.

Bondy

TuxMan

9,011 posts

267 months

Thursday 5th May 2011
quotequote all
On mine the air suck through the rad :-)

blueg33

46,309 posts

253 months

Thursday 5th May 2011
quotequote all
I am not a Noble owner but surely logic dictates that the fans assist the flow of moving air so it should not blow out of the front. I have a TVR Tuscan which has scoops for the fans in the same vein as the Noble clamshell and all correctly wired Tuscans draw air from the front towards the rear so it does not blow out of the front, Lotus Elise is the same.

worty

2,202 posts

254 months

Thursday 5th May 2011
quotequote all
Is it really sucking or blowing or is it equalisation from high to low pressure?
getmecoat

I'm not technical but I think they suck as they do come on while the car is moving.

HTH
worty


SwankBaton

763 posts

201 months

Thursday 5th May 2011
quotequote all
Def. sucks air through rad and blows out through top of clam.

Doesnt a Ferrari F50 go the other way though?

Craighb

Original Poster:

266 posts

196 months

Thursday 5th May 2011
quotequote all
Crawled out from under the car, as I've had enough tonight. Had a close look at the fans and on the inside hub is a direction of rotation. With my fans blowing air from back to front, the direction is incorrect, so they seem to be designed to suck air through from front to back. I'm going to reverse the direction so they rotate as per the decal on the fan.

Bondy - you may want to check yours, see if they are the same.

Cheers guy's, hopefully see you all next Tuesday.

wessexrfc

4,326 posts

215 months

Thursday 5th May 2011
quotequote all
Suck, defo, anyway blows just a figure of speech god-damm-it woman biglaughgetmecoat


But yes mine sucks, fans that is, great for warming up the garage. hth wink

mgbond

6,749 posts

261 months

Friday 6th May 2011
quotequote all
Craighb said:
Crawled out from under the car, as I've had enough tonight. Had a close look at the fans and on the inside hub is a direction of rotation. With my fans blowing air from back to front, the direction is incorrect, so they seem to be designed to suck air through from front to back. I'm going to reverse the direction so they rotate as per the decal on the fan.

Bondy - you may want to check yours, see if they are the same.

Cheers guy's, hopefully see you all next Tuesday.
My fans work really well, so assume they are right but I'm wrong smile

Bondy

ThatPhilBrettGuy

11,810 posts

269 months

Friday 6th May 2011
quotequote all
swankBaton said:
Doesnt a Ferrari F50 go the other way though?
Only if the fans are wired up wrong.

andygtt

8,345 posts

293 months

Friday 6th May 2011
quotequote all
blowing back to front is the wrong way... one of our fans comes on permanently when the air con is switched on (on the 3L), surely if the fan was reversed to blow forward the fan will burn out?

regardless the air should enter the front and exit the rear, if its doing anything else best get it corrected IMO.

bigsmiffy

107 posts

229 months

Friday 6th May 2011
quotequote all
Just checked my M400 & it sucks through the rad & out of the clam, maybe the plug connectors to the fans is wrong

paulcundy

1,897 posts

294 months

Friday 6th May 2011
quotequote all
Sorry but this really is in the "no brainer" category of question. The fans assist the normal path of air over teh rad. It is possible to have the fans running whilst the car is moving. Whether they are on the front blowing or on the back of the rad sucking the air should allways go in at the front and out at the back..........

Regards
Paul C


Edited by paulcundy on Friday 6th May 09:40

jamescmr2

713 posts

208 months

Friday 6th May 2011
quotequote all
agree with Paul, air flow from front to back.

being pedantic... don't fans only ever blow(push). i.e. they push air away, and of course more air moves in to take its place and the cycle continues and so on... of course the pressure changes go with this. just like the propeller on a ship. anyway i'll stop being a geek.

cheers

andygtt

8,345 posts

293 months

Friday 6th May 2011
quotequote all
nerd