Can one reverse the air flow in an evaporative cooler?

I wondered if there is an easy way to reverse the air flow in a roof mounted evaporative cooler, to essentially convert it into an exhaust fan?
Cheers!
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SweatninUT wrote:

If the motor's reversible, a small wiring addition should do it.
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I haven't been up there to take a look (steep roof), but is there an obvious tell on whether or not the motor is reversable?
Thanks
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SweatninUT wrote:

One clue is the wires on the motor. If they come out of the motor, then to a plastic connection block, then continue from there, the motor's reversible. The connection block governs the rotational direction: plug one way clockwise, plug the other = counter.
At least it's that way on a universal replacement motor I recently installed.
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wrote:

My question would be: Is the squirrel cage, or fan blade as efficient running the motor reversed? OP wants exhaust.
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the motor has to be reversible, and the fins on the squirrel cage have to be straight. if the fins are curved, they won't pull much air. you'd also have to remove the pads, and disable the water pump.
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wrote:

The pads could be left in place and the water pump simply unpowered. Dry pads don't offer much air resistance.
The biggest difficulty will be to replace the motor with a reversable and provide wiring to control the direction.
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us.com> wrote:

If the motor is reversable, the fins straight, can I change the wiring to be only an exhaust fan, i.e., not add any additional wiring? I might never need this to function as an evaporative cooler again.
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If the motor is reversable, the fins straight, can I change the wiring to be only an exhaust fan, i.e., not add any additional wiring? I might never need this to function as an evaporative cooler again.
Squirrel cage blowers are mainly centrifugal and will not effectively reverse the airflow when the motor is reversed, regardless of the fin configuration. They use leading, straight, or trailing fins but they all blow in the same direction, from the center to the outside.
Don Young
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duh, uh, you're absolutely right. It won't matter what direction the fan turns; centripetal force will cause the air to flow to the outlet as always.
Forget it. Just get a whole house fan and install it somewhere else.
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..
The physics of your arguement make perfect sense!
So, only if I ported what is now my outflow (drawing up from the house) into the center of the blower, and cut an outlet, say on top, would I accomplish my end.
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On Mon, 14 Jul 2008 11:14:38 -0700 (PDT), SweatninUT

Remove it and stick an attic exhaust fan over the hole.
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I don't know the answer to the original question, but another consideration to doing this is, if you have Up-Dux, you need to make sure that they won't be sucking hot attic air back into the house.
Jerry
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wrote:

I don't know the answer to the original question, but another consideration to doing this is, if you have Up-Dux, you need to make sure that they won't be sucking hot attic air back into the house.
Jerry
--
updux have a flap that prevents backflow when there is positive pressure in
the attic or negative pressure in the house.
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On Mon, 14 Jul 2008 11:14:38 -0700, SweatninUT wrote:

Can you find a fan with blades reversed? That should move the air the opposite direction.
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Franz Fripplfrappl
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