cooling fan direction?

[pondy]

What is the best setup for cooling fans inside my mig. Blowing air onto all the componants and sucking the heat out of the unit? Have added an extra fan, got my feed from the original fan, the wires are the same colour and didn't mark them before I cut them, not sure if fan runs the right direction now!

 

[Robotstar5]

The ones at work draw air out of the enclosure

 

[brightspark]

What is the best setup for cooling fans inside my mig. Blowing air onto all the componants and sucking the heat out of the unit? Have added an extra fan, got my feed from the original fan, the wires are the same colour and didn't mark them before I cut them, not sure if fan runs the right direction now!

if the fan is ac it will only run one way however conected if it is dc swapping wires over will make it go both ways

 

[pondy]

The main fan is ac as it connected to the mains input on the back of the on and off switch. I had added a small 12v computer fan on the back of the pcb. Not sure if I want cool air blowing off it?

 

[rtbcomp]

if the fan is ac it will only run one way however conected if it is dc swapping wires over will make it go both ways

At once?

Some DC fans are commutator-less and have electronics inside them, so reversing the connections could damage them.

On the computer equipment I worked on the fans always blew into the cabinets, via a filter on the inlet side.

It's easier to direct a blast of cooling to where it's needed.

 

[brightspark]

At once?

Some DC fans are commutator-less and have electronics inside them, so reversing the connections could damage them.

On the computer equipment I worked on the fans always blew into the cabinets, via a filter on the inlet side.

It's easier to direct a blast of cooling to where it's needed.

err it will have a job on either one way or the other dc

 

[Shox Dr]

I'd have it blowing in that way you can make a filter to fit over it. If you have it sucking air out, then you have the problem of filtering every hole in the case

 

[rich r]

If you need to cool a specific component (eg a transformer) then you'd usually blow cold air at it. But to cool an enclosure you'd normally just pull the warm air from it, allowing cool air in through vents at the opposite end.

Computers (servers at least) tend to have fans to suck cold air in at the front and fans to push hot air out the back, so it's a bit of both. The hottest components (CPUs, RAM, PSUs) are located at the back, so the hottest air spends least time inside the case.

For a welder, I'd say it's maybe better to suck hot air out than blow cold air potentially with fine metal particles in it, in. Unless you fit some form of filter over the fan intake. The air flow through vents in the case will be much slower and unlikely to pull those particles in so easily.

 

[Luke]

I'd have it blowing in that way you can make a filter to fit over it. If you have it sucking air out, then you have the problem of filtering every hole in the case

This makes sense.

If you suck air out using a fan, it will come in wherever it can, and you'll have little chance of filtering it all, even if you fit a filter over an inlet.

At least if you blow air in, you can filter it and you shouldn't get dust coming in from anywhere else.

 

[Shox Dr]

I'd say it's maybe better to suck hot air out than blow cold air potentially with fine metal particles in it, in. Unless you fit some form of filter over the fan intake.

See my post above. Link to filter fitted to plasma and TIG units

The air flow through vents in the case will be much slower and unlikely to pull those particles in so easily.

Don't you believe it. If there is a hole dust WILL get in

 

[Hitch]

Had a look today, all our inverter machines suck air out of the case.

 

[Lawnmowerboy]

Computer fans are rectangular with through holes right? so why not just turn them 180 degrees round?

 

[MattF]

The most efficient cooling method is extraction. There is usually an arrow on the fan housing to show which way the airflow goes through it. A fan at the top of the cabinet will extract warm air directly, and fans in other positions are generally more to direct air flow across certain components/areas of an enclosure. You want to aim for having the fans at the furthest point away from the air inlet(s).