Generator box fan

[Elbear1]

So i keep my generator in an aluminum tool box on a hitch carrier. The fan I was using was a cheap tornado 12v fan and id just keep the lid open. Well the fan died the other day and caused the capacitor to melt.

So i purchased a 7" radiator push/pull fan. Plan is to mount it on outside rear of box after cutting appropriate size hole for it. Turns out it pulls much better than pushes.

What say yee use it as a puller fan? Flip the blade and push air into box? Box has vents on opposote side and bottom for air to escape.

Ideally id like to keep lid closed. Its very quiet inside the box as far as annoying neighbors.

 

[highdesertranger]

"Turns out it pulls much better than pushes"

they usually do

highdesertranger

 

[Elbear1]

Its was designed to be either. Of course a standard radiator fan is pull only.

 

[highdesertranger]

it might be designed to work both ways but it always works better in one direction. just the physics of fan blade design. highdesertranger

 

[Elbear1]

You think it will work pulling?

 

[highdesertranger]

well there is really only one way to find out. remember the intake side should match the exhaust and that should match the CFM of the fan. that will get you the maximum air flow. highdesertranger

 

[Spaceman Spiff]

Look at any electrical box with a fan; they always blow out.  You get better cooling with a fan trying to remove air from a chamber.

 

[MrNoodly]

Whether it's pulling or pushing depends on which side of the fan you are.

 

[Elbear1]

There ls no room to mount it inside or backward.

 

[maki2]

Build or adapt an external housing for it that has a hinged door and is screwed to the big box with a gasket between them and a gasket on the hinged door.  Open the door when you turn on the fan. You can probably find something on ebay for a reasonable price that can be modified by cutting part of the back side of the box out. If it is hinged at the top that will help keep out the rain with the door acting as a protecting roof over.

 

[Elbear1]

Good idea....If I have to. But for now it violates KISS. I will mount and see.

 

[MrNoodly]

...Flip the blade...

If you mean removing the blade from the shaft, flipping it over and remounting it to the shaft, that won't change the direction of air flow. The blades will still be angled the same way, only with a less effective shape trying to move air. If you want to change the direction of airflow, you need to switch the wiring so the motor turns the opposite direction.

 

[DannyB1954]

A fan will not push out more air than it pulls in, (in does not create air). Nor can it pull in more air than it pushes out. Fan blades are not designed so that their rotation can be reversed. Swapping the power leads to the motor to make it turn in the opposite direction does not work unless you can also take the blade off and turn it 180 and put it back on. There is an inlet side of a blade and an outlet side.

It is also good to have airflow into an inverter type generator after you shut it off. The electronic box that is the inverter is mounted so that cooling air going to the engine first cools the electronic box. When you shut off an inverter generator that air flow stops and the heat from the engine cooks the inverter shortening it"s life.

I would put the fan so that the air flow is in the same direction as when the engine is running, (usually in at the opposite side of the engine and exhaust), and then keep the fan running for 10 minutes or so after you shut down the engine to remove the engine heat.
I
would also put the fan on the inverter side of the generator so that the fan motor is running in cool air and not in air that has been heated by the generator.

 

[MrNoodly]

...Fan blades are not designed so that their rotation can be reversed...

Except maybe those in things like Fan-tastic vents that can blow in or out. Not that they're the most efficient blade design.

 

[Elbear1]

Inverter...lol no. Not even voltage regulated. Straight old school rpm = voltage

 

[Elbear1]

Well brand new generator lasted under 3 minutes inside box. Does same as old now....5vac output

Old one lasted 3 years

Loving life

 

[bullfrog]

It would be nice to see some pictures of the generator, box and how the fan is mounted. Baffolds on outside vents are about as quiet as you can do and still keep enough air flow. Maybe extending the exhaust and muffler outside the box would help. Generator noise is a problem for everyone it seems.

 

[Elbear1]

Its all plumbed out of box. Wishing i just bought a dc to dc converter and extra panel. Save me space too.

Supposedly its the capacitors that are going out. I got one on order. Will do a capacitance test tomorrow.

 

[Elbear1]

Well thankfully i found a wire came off the circut breaker. Its working fine now.

In want to add for anyone thinking about doing this its nice to have it in a locked and vented box and all. Can just run it at a walmart without much trouble. But an open frame still isnt as quiet as a honda or honda clone. After exhaust is ran outside of box and the various rattling from the box its about inbetween an open frame and inverter unit. Takes about 30-50 yards to not hear it at all.