What to do with old HVAC squirrel cage fans?

[Gigem]

I had two HVAC systems replaced at my house yesterday, and I salvaged the squirrel cage fans from the old systems in the attic. Looking for some creative ideas for how to rig these up to use in the garage and other outside spaces to cool things off this summer. Anyone have any feedback for me?

Thoughts and questions:

1. I want the end result to be "relatively" safe and portable. On wheels perhaps. Probably should put some mesh over the exposed spinning blades...

2. I've heard that the fans are designed to have some resistance to airflow intake to operate properly. Any thoughts on that?

3. I will surely need some assistance on how to wire it up properly. I'll take pictures of the wiring soon.

Thanks!

 

[The Cobbler]

a buddy made up a fan from his old furnace. uses it extensively in summer to move the air in his garage. no reason to add resistance .
the wires are speed control, not able to help you there.
ps, I made up a fan to hang in my basement window 10 yrs ago. I wanted to paint the floor with oil base paint, I put the fan in a window & let it run for 24 or more hrs to keep the fumes at bay. worked like a charm
mesh for protection is a must

 

[kbs2244]

I used one in the shop for a few years.
I found the breeze was just too strong and sold it.
Now I use a 20 inch, 3 speed, box fan set on "med."

 

[brownbagg]

i use one for a welding exhaust fan, hook it to the wall and then got some three inch pvc to snorkle whatever im welding

 

[brownbagg]

when i did ac work on cars i would use one to blow air across the radiator

 

[Terranova]

Check out post #150.
https://www.garagejournal.com/forum/showthread.php?t=256086&page=8

 

[Kaizen]

I’m going to use a similar fan or two for garage exhaust. I like the little hole it has instead of a big 24x24 hole


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[bob from indiana]

A friend has one in his shop. It is in a plywood box with chicken wire guards. The box is on wheels and has a long cord. The air comes out the front and it moves a lot of air. I have one from an old furnace but haven't used it yet.

 

[txvwnut]

I used mine to exhaust fumes out of the shop. I bought a three speed chain pull fan switch wired it up so I’ve got multi speeds. The fan is mounted through the wall with a shutter on the outside to keep the weather out.

 

[wasfuzz]

Buddy built dust collector units that he positions around his shop with furnace filters on them.

 

[LS6 Tommy]

I used an old one to make a radiator cooling fan for working on the GT1 car. You may need to restrict the outlet if you don't have any ducting. What happens is the motor overspeeds when there isn't enough static pressure and it can draw too much current. That may or may not give you any obvious symptoms. You won't know unless you read the amperage when it's running.

Tommy

 

[marinusdees]

I used an old one to make a radiator cooling fan for working on the GT1 car. You may need to restrict the outlet if you don't have any ducting. What happens is the motor overspeeds when there isn't enough static pressure and it can draw too much current. That may or may not give you any obvious symptoms. You won't know unless you read the amperage when it's running.

Tommy

When it draws too much current, it overheats and the built in thermal protector shuts the motor down, until it cools. If you want it to run continuously, you have to restrict airflow to the extent that current draw is at or below nameplate rating. Use a clip on ammeter to determine when current draw is at this level. If you don't mind occasional shut down, let 'er rip

 

[redmondjp]

I used an old one to make a radiator cooling fan for working on the GT1 car. You may need to restrict the outlet if you don't have any ducting. What happens is the motor overspeeds when there isn't enough static pressure and it can draw too much current. That may or may not give you any obvious symptoms. You won't know unless you read the amperage when it's running.

Tommy

The motor actually slows down, not speeds up, when there is less restriction as it is pumping more air. This increases the load on the motor, which increases the current that it draws. This type of blower speeds up when you block the airflow, just like in your shop vacuum.

 

[Nowater]

I built a box around mine and put filters on the inflow side. High speed is usually too much, so don't worry too much about speed control. Low speed is all I use.

Mine is hung in the air mounted on a column.

 

[mizzoutrover]

Ditto the shop air filter, you can find plans online n how to build. You can on wheels to move where you are sanding or mount near the ceiling. Some plans add timers to the circuit to run for 15 or 30 minutes after you stop working to get all of the dust.

 

[MFolks]

Old furnace fan(blower) wiring

Squirrel cage blowers make great fans. BLACK is ground, WHITE-negative and RED-positive. Looks like BLUE, WHITE, and RED coming from the motor. Read the info on the motor, it should have split capacitor in it, may have to change the wiring from 220 to 110. Looks like a 1/4-1/5 horse. Ask a local HVAC guy, feed his ego and be rewarded. If its a 110 just throw a three prong on it and breeze away. I pulled some romex off the coil and pulled a spare heavy duty three prong out of my tool bucket and had a great workshop fan w/ a super long cord.(put a triangle shaped piece of plywood on one side to stabilize it, and a small board 1x2 across the front as a foot/stabilizer, made it quiet.

WHITE-RED : low speed
WHITE-BLUE : medium
WHITE-BLACK: high

WHITE ----- common

BLACK ---- high speed

BLUE ---- medium high speed

ORANGE --- medium speed

RED ------ low speed

in some cases YELLOW can be common in the place of WHITE. you don't have YELLOW but just a note.

 

[ScottsGT]

I’ve got a 110V single speed I’ve had for close to 40 years. At one time I used it to pull paint fumes out of a paint booth when I had a shop. I now use it sitting in a milk crate when I want to circulate air from my A/C cooled workshop into my garage with the doors closed. Hehehe..I really need to ditch the old plastic milk crate and build a box to hold it.

 

[NUTTSGT]

I had one for a few years. I didn't like the floor space it took up and listening to it was akin to the winter time sound of a space heater, just a bit quieter. I got rid of it.

Seeing what some of you have done with the filter, that is a great idea. If I had the room and a smaller one(than I had before) I'd do something like that.

 

[marinusdees]

Old furnace fan(blower) wiring

Squirrel cage blowers make great fans. BLACK is ground, WHITE-negative and RED-positive. Looks like BLUE, WHITE, and RED coming from the motor. Read the info on the motor, it should have split capacitor in it, may have to change the wiring from 220 to 110. Looks like a 1/4-1/5 horse. Ask a local HVAC guy, feed his ego and be rewarded. If its a 110 just throw a three prong on it and breeze away. I pulled some romex off the coil and pulled a spare heavy duty three prong out of my tool bucket and had a great workshop fan w/ a super long cord.(put a triangle shaped piece of plywood on one side to stabilize it, and a small board 1x2 across the front as a foot/stabilizer, made it quiet.

WHITE-RED : low speed
WHITE-BLUE : medium
WHITE-BLACK: high

WHITE ----- common

BLACK ---- high speed

BLUE ---- medium high speed

ORANGE --- medium speed

RED ------ low speed

in some cases YELLOW can be common in the place of WHITE. you don't have YELLOW but just a note.

Find a rotary switch with three positions (and off) and you have a three speed blower, so if it's too noisy, slow it down. I did it this way and it is great for exhausting fumes from the shop. Or, it sits under the bench.

 

[OccupantRJ]

English bulldogs are extremely hot natured and heat restricts their breathing. Mine has his own squirrel cage fan in the shop to cool off with. It has wheels and a loop handle to make it mobile as needed.

 

[jimindm]

I have seen many mounted on an old push mower. Take the engine off and mount the fan. Roll it where ever you need it.

 

[marinusdees]

English bulldogs are extremely hot natured and heat restricts their breathing. Mine has his own squirrel cage fan in the shop to cool off with. It has wheels and a loop handle to make it mobile as needed.

Do him (?) a favor, and equip it with a four position rotary switch so he can select from three speeds. Or, maybe that's beyond his ken??

 

[Gigem]

Great stuff guys, thanks!

 

[gearhead1]

I have one I set up in the summer time when working in the garage with no AC and works great. As OccupantRJ mentioned, put it on wheels and you can move it to where you are working.

If I come across another, I will put one in the attic window to get a good draft inside the work shop and get the heat out.

 

[John in OH]

These belt-driven fans are great for use in "small scale" paint booths! Keeps the motor out of the flow of overspray so reduces the chance of fire from motor operation.

See current thread on subject: https://www.garagejournal.com/forum/showthread.php?t=418848

 

[LS6 Tommy]

The motor actually slows down, not speeds up, when there is less restriction as it is pumping more air. This increases the load on the motor, which increases the current that it draws. This type of blower speeds up when you block the airflow, just like in your shop vacuum.

You are correct. I should have said it overloads, not overspeeds. I guess I'm getting a little rusty.

Tommy

 

[nadogail]

I had one and after the thermal protector in the motor kept opening, discarded it because I was not aware it needed air flow restriction.

Lesson learned.

 

[Shootinok]

The restriction is the key. I blocked mine while running and measured the amp draw. When it was 15 amps (which is listed on the motor) I marked it then attached the plate in the front. Covers about 1/2 the opening.

Originally I just wired the med/high wire on mine and Wow that baby really moves some air. Been using it on these really hot Oklahoma days but wanted to have the option to turn it down.
I ordered this switch https://www.amazon.com/gp/product/B00NTROK8Y/?tag=atomicindus08-20 and it’s really nice now to have 3 speeds.



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[steel 35]

Check out post #150.
https://www.garagejournal.com/forum/showthread.php?t=256086&page=8

nice! Thank's

 

[jsaw]

We have 2 of them at work. They move a lot of air, and are quiet
A local HVAC guy told us to measure the amperage draw of the motor. The restrictor plate on the fan housing was correct, as the amperage draw was not excessive

 

[MAYOR28]

I used one to build an Air Scrubber for airborne dust in the shop. Haven't finished it all the way yet, but it has one of those deeper 4" filters and a 1" pre-filter.

I have one more fan that I got from an HVAC shop, I plan to use that for a small telephone booth sized spray booth.

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