<VV> alternate fans

[jay m]

On 3/16/2013 8:29 PM, Gary Moore wrote:
> I should not have used computer fans as an example. There are fans that are used in convention ovens that can withstand the heat. This was meant as a "what if" question. So what would happened if a pair of small heat resistant fans were placed at the back of the lower shrouds that came on when the thermostats opened the exhaust doors? Would  the back pressure that causes the top fan work less efficiently be reduced?
> During the electric fan test were there any measurements taken with the heater blower on? This would be a near equivalent.
> GMoore
as always, there are multiple factors to consider:
- how much pressure differential can the proposed fan(s) develop at the 
required airflow?
- a fan might work better pulling than pushing because the turbulence 
created by the fan doesn't have to straighten out to go through fins.
(electric fans on water pumpers work better pulling than pushing, I'm told)

i expect that most 'fans' develop almost zero pressure differential. I 
imagine they would help a bit more than that.

If you could take a Corvair (or other) blower that would supply more 
than enough volume and pressure, then drive it with a variable ratio 
system (like snowmobile?) and control ratio by head temp?
Then you'd never waste power by pumping more air than needed, and always 
have enough cooling.

Oh, well - pipe dreams, my specialty!

-- 
Jay