Cyclone motor external cooling fan ideas..

[Jim O'Dell]

Good Holiday afternoon all!! Well, I've got my thinking cap on for a problem I have created for myself. To get the ducting above my ceiling, my cyclone is shoved up into the attic in my shop. I have a couple inches of clearance between the motor and the decking plywood, but it is right at the peak of the roof. At this time there is no attic ventilation, but I will be adding 2 turbines before all is said and done. But I am still concerned about the motor. I'm thinking about a 220 volt "muffin" fan I can wire into the cyclone motor's circuitry so it comes on every time the cyclone comes on, and position it to blow across the motor. I could go with a 110 volt unit, or even a 12 volt unit (I'll be running my shop ex-car stereo unit off of an Astron 35 amp power supply). but these would have to be turned on separately. Winter time of course would be no problem, but these hot summer days here in Texas could roast a motor.
So, what do you think?? Is this a viable thing to try? I've found a couple sorces for the 220 volt units for under $30.00. And what kind of cfm should I shoot for. I think the ones I saw were 105, and 110, and were about 5" square. Thanks for your thoughts and ideas! Jim

[Steve Stube]

I you do as you said, "but I will be adding 2 turbines before all is said and done." before your next WW project all should be fine.

You could measure your attic space temperature. Most motors are rated to operate continuous at up to 40 degrees C.

[Steve Stube]

Upon further reflection, is it possible for you to build a little cat house in the attic space around the DC motor area that would effectively extend your ceiling height in this small space.

[Jim O'Dell]

Steve, I had thought at one time about building a fake chimney, with a covered vent, or powered vent on top of it, when I had planned on the cyclone being in a different spot in the room where there was less headroom than the gabled spot it is going in now. I guess it could be done still, but it would set me back a lot getting this shop up and running. I would prefer not doing that and I would prefer not opening up the roofing, except for a couple turbines as noted before.
To explain for you a little more, I am building a closet around the cyclone, and the walls will extend up to the roof to seal this off. The exhaust will be ducted back into the shop via a folded design based on Jim Becker's ideas and suggestions for sound control. I have installed some of the foam chutes to keep an area close to the roof open for the few times we actually get cold weather so that it breathes. This is what made me start thinking about the heat from the motor, and therefore the fan to blow across the motor to disipate the heat instead of it collecting at the peak of the roof. Plus if this 4' X 3' section is closed off, the turbines won't help a lot here for temp abatement. Does this make any sense? I'll add a picture to show what I mean.
Thanks for taking the time for the suggestions! Jim

[Steve Stube]

It appears you are very tight to the peak alright. It is important to let the heat out of the peak for the sake of the roof, any A/C you may want below and yes probably for the motor too. Actual temperature measurements near the motor location would be a good indication of how serious the problem might be. If it isn't possible to do the turbine vent or Cobra vent on the one rafter space alone above the motor could you shroud the motor to the gable end and install a couple of 3" or 4" round push in screen vents (the higher the better) add the muffin fan to the gable end wall over one of the vent holes, pulling outside air into this cavity - it will find the other hole to exit by. Again actual temp. measurements will indicate if the fan is necessary - my guess is probably not once a vent to the outside is established. You might be able to form up some aluminum flashing to encase the motor to vents box/enclosure. Rivets and or tape any seams - perhaps mock it up with cardboard and build at the bench. Fun.

If you do put a fan in to cool I would suggest you protect it and the wire to it. My concern is fire in an enclosed space being fed by whatever amps are available at the relay or motor. I like the low voltage approach best where the relay closing will power a 24V transformer in the relay box and wire a 24V fan from that. The 24V fan you have is 24V AC, right?

[Norman Hitt]

Jim, I think Steve's idea to bring in outside air to pass across the motor is an excellent idea, since it would be much cooler than any attic air you would blow across it, and you could just use snaplock pipe to direct that air from the fan directly ato the motor.

Another thing that I believe would help is to fasten some insulation to the underside of the roof for at least a 5' x 5' area centered directly above the cyclone's motor. This insulation would cut down somewhat on the "Radiated Heat" from the Roof itself, right around the DC's area. Without insulation against the bottom of the roof, the Radiated Heat will normally be VERY present for 2' to 3' below the roof which increases the ambient temp in that area considerably.

AS for powering a 110 V fan when the DC comes on, how about just running a neutral and ground wire to the fan, and then taking 110V from one hot leg of the 220 that goes to the /DC motor. If you take it off from a point BETWEEN the RELAY and the MOTOR, it will power up at the same time the DC does, with no additional controls required, and the fan would have such a small pwr requirement, that the DC motor would never notice it.

Note: I would not hard wire the little fan, though, I would run hardwire to a 110V recepticle, and then you can just plug it in or unplug it when you need to replace or repair it, or just not use it, such as maybe in the winter time. On that note, you might even want to put a wall switch in just for that outlet, but if you do, be sure to bring the HOT wire from the 220V leg to the switch first, and then on to the outlet.

Good Luck, and let us know what you come up with.

[Jim O'Dell]

Something else to think about here, is there will already be shop air flowing in this closet. I have the exhaust of the cyclone that will go through the filters, then exit to the left of the cyclone. I would position the fan to take this air on up to blow against the motor, so it's not like the pure attic air. Does this info help? Jim.

[Steve Stube]

If it is a TEFC motor all that will be necessary is to supply colder air to the motor fan at the top end. 40'C/104'F Don't buck the natural flow pattern of the air passing over the motor (caused by the motor fan output) as you may destroy the cooling efficiency altogether.

You might look here for info on motor temperature effects.
http://www.iprocessmart.com/leeson/leeson_motor_temperature_article.htm

[Norman Hitt]

Jim, to get an idea of what to plan for, I think the FIRST thing you should do, is to hang a Thermometer right by the motor, with everything off, and see what the temp is during the heat of the day. I don't think Steve knows just how hot our Attics get down here in Texas. :D (104* F would be COOL up there, except for maybe 3 or 4 winter months). One other thing to remember, is that the return air coming out of the filter will probably be a little warmer than the ambient air due to the slight compression factor created by the cyclone fan.

Now, Does your DC motor have a cooling fan built in? If it does, you will need to pass the air across the motor from the side, OR from the top end of the motor, to keep from defeating the airflow of the cooling fan, as Steve mentioned. If this is the case, then you would still need a tube/duct to take the shop air across the fan without picking up the heated attic air. If the DC motor does not have a built in cooling fan, then you could simply locate your little fan down lower in the "Sound proofing enclosure", and point it toward the DC motor for cooling.

[Jamie Buxton]

You're on the right track, thinking about the heat emitted by a cyclone. I put a 2 hp cyclone in my shop, and the shop got noticeably warmer. Once I thought about it, the cause is obvious. The cyclone's 2 hp motor is running at quite near full capacity any time it is on. (In contrast, the motor on my table saw is running at the full rated horsepower only when I'm ripping 3" oak real fast, which is almost never.) The cyclone draws about 11 amps of 220. That's 2300 watts of electricity, which all turns into heat. The typical plug-in electrical room heater doesn't produce that much heat. So your cyclone is going to making lots of heat.

[Jim O'Dell]

Thanks again guys. The motor in question is the Leeson 5hp compressor duty motor (true 3 hp). It is not a TEFC, so no fan of it's own. I thought about using some duct work to take air from the shop and pipe up there, with an inline HVAC booster fan, but those things are pricey. I guess I could make something using a motor and fan from a oscillating fan, pull cooler air from the floor area, possibly through a disposable filter, then up to the motor area. I'll have to give that some thought. And yes, Norman, a target temp for Texas in our attics for the summer would be 104. 150 to 160 is probably more the normal range, and higher without proper ventilation. I'm lucky in that my shop and house are completely covered by trees. Makes a big difference. I'll also try your idea of the thermometer by the motor to measure "normal" temps before the turbines are installed, and then after installation. Thanks for the good idea there.
Jamie, I hadn't even considered that the cyclone itself would put out heat, other than the motor. I'll monitor that once everything is up and running (may be a few months still).
Steve, thanks for the web site. I'll look at that this evening. Jim.

[Dick Strauss]

Jim,
I'll bet that your attic gets close to 150*F (50+*C) on a hot day. Assuming you decide you need a fan to cool the DC, I'd be tempted to use a 15" gable end fan for cooling. Most of the units come with a adjustable "thermostat" to control the activation temp of the fan. The 110V units run about $40-50 at the local big borg. Boy will they move the air (about 1000cfm) since they are designed for 1500 sq ft attic ventilation! You might also consider a cheap box fan with thermostat control. Both options should do a better job for less $ than the 220V option you mentioned. Either of these options can be installed with a plug for repairs and would shut themselves down at the right temp.

Good Luck!
Dick

[Jim O'Dell]

Dick, if I put in a gable fan, or a powered roof vent for that matter, I'd be sucking the air from my shop, via the cyclone, right out doors. Now the problem would be simpler if I ducted the cyclone outside, then I could just work on getting cooler air from the floor up to the motor. But you know, the exhaust fan wouldn't be on in the cooler times, and the return air would then come back into the shop by way of the folded return vent, thus keeping some of the heat in when it's colder. Exhausting the hot air outside would probably take some of the noise with it during the hotter days. HMMMMMMM.... I don't have any gas appliances to worry about co2 problems with sucking air outside. That might work best! In my situation, the gable exhaust would be a pain to install now, but the powered roof exhaust wouldn't be any more problem than a turbine would be, except for the power. Others have probably mentioned this, but it didn't sink in til now. It's funny how talking problems through with others helps to recognize the right answer.
Thanks everyone. I'll mull this all over a bit before I decide for sure, but you've all been a big help. Jim.

ps: Dick, the 220 volt option on the muffin fan was less that 30.00, and 220 is already there with the motor. I would have just branched off at a junction box after the switch so both would turn on at the same time. The power it would require would have been minimal, so I don't think it would have been a problem. But it may not move enough air to help.

[Dick Strauss]

Jim,
They do make a gable end vent system that will stay closed when not in use. Gable end vents tend to last 5+years while the roof fans tend to last 2-3 years when mounted in their normal locations (at least in my area of OH). If you decide to go the turbine/roof vent route, you can always seal the opening for winter to retain the heat in the shop.

You can also use these as simple fans blowing past your DC. Yes, it will increase the temp in your shop during Summer although the breeze from the fan will probably make it feel cooler. You could have the added benefit of some slight forced air heating in the Winter. Either way, keeping your fan under about 110* with the increased airflow will make it last much longer.

Good luck,
Dick