Heater/Air Conditioning circulating fan needed

[WZ JUNK]

I have a need to move more air from a Vintage Air unit I mounted in the trunk of a street rod.  I built a fiberglass duct along the transmission tunnel up to the dash and the two fans on the unit do not move enough air to suit me.  I have been told that squirrel cage fans do not move air good in a restricted space.   The last two days I enlarged the duct and it is as big as I can make it now, but it still does not move enough air.  I need a blade type fan about 4 inches in diameter to place inside the duct to boost the air flow.  I went to the salvage yard this morning and looked at some vans with rear air but I did not see anything that would work.  I thought that maybe and over the road big truck or a motor home might use a fan system like this.  Has anyone got and idea for me.  I am nearly at the end of my rope on this one.

[GPster]

Do you have room under the dash for a blower? Maybe if you took that 4" round and put it in the suction of a blower you could suck/blow the air. A fan blade is not going to be at its top efficiency with-out a venturea and anywhere there is a retrictionyou're going to loose flow because of the distance you're pushing it. So maybe you need a little push pull. Some RVs and extended vans use two evaporators so that they are cooling where it needs cooled rather than trying to move air where it's needed. If the air is left to stagnate at the coil you'll have "freeze-up" problems. Maybe you can build an air return package and force the air into the unit. What are you doing for windshield defrosting? Maybe with an extra blower under the dash (first suggestion) you could use some of the air that you suck from the A/C unit to defrost with by opening a little damperwhen you want some on the windshield. GPster

[OlBuzzard]

What about using a fan from a computer?  I don't remember what the voltage is on them but enjenjo might.  They are sure cheap.

[enjenjo]

What about using a fan from a computer?  I don't remember what the voltage is on them but enjenjo might.  They are sure cheap.

12 volt, and come in many sizes

[58 Yeoman]

...and here I thought that squirrel cages moved more air than fan blades.  Learn something new everyday.

[WZ JUNK]

I looked at Radio Shack today and they have one the right size but it did not flow as much air as I would like.  There is no room in the dash area of this car as the engine is set back and the dash area has only enough room for the gauges and essential stuff.  Thats why I put this Vintage Air trunk unit in the car.  Vintage Air recomends that you put two rear side vents and two vents in the package tray.  Owner wants the vents in the dash.  I am going to the local RV Salvage tomorrow.  I am also going to look in some of the industrial supply catalogs on the net tonight.  Thanks to everyone for the help.

[Sean]

They sell Booster fans for long runs of Ductwork. I have one in my basement that is tapped into the 6" round duct that leads to the room furthest away from the Furnace. It seems to work well, but it is a squirrel cage type blower.

I imagine you could pull the motor off something like that and put a 12v Blower motor on it.

[WZ JUNK]

They sell Booster fans for long runs of Ductwork. I have one in my basement that is tapped into the 6" round duct that leads to the room furthest away from the Furnace. It seems to work well, but it is a squirrel cage type blower.

I imagine you could pull the motor off something like that and put a 12v Blower motor on it.

Good idea.  I modified the duct tonight and I am experimenting with one of those defroster fans that are used on big trucks and busses.  It still seems to me that a squirrel cage fan in the duct would work.  I may have to try that too.   I was told that squirrel cage fans do not suck well but since this one would be force fed it might make the change I need.  I guess if at first you do not succeed, keep on sucking.

[soldermonkey]

My wife's 96 Caddie STS has a booster fan that provides air through a floor duct that runs under the center console. I do not know the type of fan, fans location (sounds like it is in the duct near the register in the rear of the console), nor the cfm rating. The control for the fan is on the rear of the console just above the vent registers and is variable in speed and is completely independent of the fan/blower for the front of the car.

You might test drive one and try it out.

Good luck
dave n

[WZ JUNK]

My wife's 96 Caddie STS has a booster fan that provides air through a floor duct that runs under the center console. I do not know the type of fan, fans location (sounds like it is in the duct near the register in the rear of the console), nor the cfm rating. The control for the fan is on the rear of the console just above the vent registers and is variable in speed and is completely independent of the fan/blower for the front of the car.

You might test drive one and try it out.

Good luck
dave n

Thanks,  I will try to find one of those.  It sounds like just what I need.  I know that some new cars come with individual climate controls and I thought that they might have a secondary blower.

[Sean]

Here is the one in my basement. The pipe is 4" not 6" like I thought. Looks like it just cuts in from the bottom and the cage sticks up into the air flow. Not really sure how it works because it was there when i bought the house.

It feeds one of my kids bedrooms on the 2nd story, so from the booster to the outlet is at least 13'-14'. Without the booster you can barely feel the air coming out of the grille. With the booster, it blows enough to move the curtains slightly. I don't think it is "sucking" so much as just giving the air velocity a little boost...

[48ford]

Try Boat u.s., get a blower that you use for a bilge blower,they fit inside a 3" or 4"duct like a cloths dryer uses,run on 12 volts. May be what you are looking for
Russ&Irene

[48ford]

Try Boat u.s., get a blower that you use for a bilge blower,they fit inside a 3" or 4"duct like a cloths dryer uses,run on 12 volts. May be what you are looking for
Russ&Irene