Air cleaner - blower unit suitability study

[Steve_P]

Sounds like an impressive subject, doesn't it? My study consists of this: ask a bunch of cool guys you know and see what they think.

So I did the whole "call around to the HVAC companies and see what you can get for free" drill, and landed the blower out of a replaced furnace. Since I've since forgotten the wiring scheme for this motor after the guy told me, I jumped online to learn more.

I have a Fasco model D-166, and according to their website it is a 115V, 1/6-1/9 hp motor turning at 1050 RPM. The "1/6-1/9 hp" caught my eye and started wondering if it's going to have enough "oomph" to work as an air cleaner?

Then I realized that maybe I was confusing the horsepower needs of an air cleaner with those of a dust collector, swinging that big wide impeller blade (this thing has a squirrel cage blower attached).

What are your collective thoughts, O gathering of enwizened ones?

[gmack5]

As long as it will pull air thru your filter stack at a reasonable rate, you should be alright.
Course there's only one way to find out.
You'll have to do a mock up to check it out, maybe use cardboard for the enclosure, mount the filters that you propose to use, set the blower in one end and see what happens.

[LCHIEN]

quote:Originally posted by Steve_P

Sounds like an impressive subject, doesn't it? My study consists of this: ask a bunch of cool guys you know and see what they think.

So I did the whole "call around to the HVAC companies and see what you can get for free" drill, and landed the blower out of a replaced furnace. Since I've since forgotten the wiring scheme for this motor after the guy told me, I jumped online to learn more.

I have a Fasco model D-166, and according to their website it is a 115V, 1/6-1/9 hp motor turning at 1050 RPM. The "1/6-1/9 hp" caught my eye and started wondering if it's going to have enough "oomph" to work as an air cleaner?

Then I realized that maybe I was confusing the horsepower needs of an air cleaner with those of a dust collector, swinging that big wide impeller blade (this thing has a squirrel cage blower attached).

What are your collective thoughts, O gathering of enwizened ones?

if you foudn the website info, you should also have found out the CFMof that unit.

Typically it does not have to move a lot of pressure or head, therefore not too many HPs are required relative to a DC.

If it does 800 or so CFM you will likely be OK.
My delta does 850 CFM, others do more or less.
You can caluclate how often it will clean the air in your shop
by calculating the volume of the room (L x W x H).
Divide the CFMs by the volume and multiply by 60 - will tell you how many changes per hour will be filtered.

You'd like to have 5-10 changes per hours since its not 100% efficient. (e.g. since the circulation is not perfact some air will not be filteresd at all and some will be cleaned 20 times over...)


Or did you confuse RPMs and CFMs? 1050 is not a usual RPM for an induction motor... but 1050 is a reasonable number for CFMs.

[Steve_P]

Thanks, George, that's pretty much what I was thinking (as long as it moved a good amount of air through the filter, it'd work). I hope to have it running this weekend so's I can test it out.

Loring, I doublechecked and it was indeed RPM's, they weren't going to make it easy for me to find out how many CFM it moves. I may try and find the blower's model # to track down the CFM, but the site was for the motor itself as opposed to the blower, so I guess it makes sense they'd focus on the spinnybits.

Thanks again guys, I think I'll keep it and see what it does!

[dedaddy]

My blower has a 1/3 hp motor at 1750 RPM. It moves about 1400 CFM. On the nameplate of the motor there should be an AMP rating. You need to make sure you don't draw more than 80-90% of that when it is running. If you do draw more, you will probably over heat the motor and trip the internal thermal protection switches.

1050 RPM motors are 6 pole. The syncronous speed would be 7200 divided by the number of poles. Then a 2 pole motor run at 3600 RPM or less, 4 pole runs at 1800 RPM or less and a 6 pole runs at 1200 RPM or less. As the load increases the speed goes down for induction motors.

[WeekEndDad]

I built a hanging air cleaner a few months ago, but noe cannot locate the post.
Here is a link to the pictures and a write up I did.

It used an old 3 speed furnace blower and 16x20 filters.
I used the Delta electronics which allowed me to set the speed and also a timer, with a remote.

http://f1.pg.briefcase.yahoo.com/wkenddad]

[url]

Look in the air cleaner directory

[gmack5]

I remember when WeekEndDad published his Air Cleaner and thought at the time it was excellent work.
There's a copy of his plans on his site, referenced above.
I'd take a good look at them!
I just started a down-load of them myself, maybe you should think of doing the same.

[Steve_P]

Thank you, Ray, nice pics! I am downloading your plans now. Didn't realize that Delta might sell the electrics separately, that's something I'll have to look into!

Thanks again to all for their input, will let you know how it turns out!

[Talley-Ho]

Most furnace fans will deliver about 400 CFM per ton of cooling so 800, 1,200, 2,000 are all pretty typical air volumes.
These fans (stamped steel forward curve) are very quiet and deliver good air volume at low static pressure (resistance).
The air volume drops very quickly when there is too much static on them though.

If you run a standard 2” pleated filter it will more than likely be in the 30” efficiency range at 500 feet per minute.
All filters need to be sized for the proper velocity for them to function properly, aim for 300 to 500 feet per minute. Example 24”x24” filter = 4SQFT, and you have a 1000 CFM fan take 1000CFM /4SQFT=250 feet per minute.
It will also help to give them a light spray of filter oil to help them trap the particulates.