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!

"Jerry" wrote in message
...
On Jul 14, 11:14 am, SweatninUT wrote:
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!

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.

"SweatninUT" wrote in message
...
On Jul 14, 1:43 pm, AZ Nomad wrote:
On Mon, 14 Jul 2008 12:27:32 -0700, charlie
wrote:
"SweatninUT" wrote in message
...
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!
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.

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.

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

On Mon, 14 Jul 2008 21:14:22 -0500, Don Young 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.
It depends if you're willing to get on the roof to flip a switch.

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.

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.

On Mon, 14 Jul 2008 11:14:38 -0700, SweatninUT wrote:

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!

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



--

=================================================
Franz Fripplfrappl

On Jul 14, 8:14*pm, "Don Young" wrote:
"SweatninUT" wrote in message

...
On Jul 14, 1:43 pm, AZ Nomad wrote:





On Mon, 14 Jul 2008 12:27:32 -0700, charlie
wrote:
"SweatninUT" wrote in message
....
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!
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.

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.

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- Hide quoted text -

- Show quoted text -

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.