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EmmisonJ
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hm and i definitely can't do a 90 degree to simply mount the blower horizontally on top of the fume hood as the picture attached shows which would be
a very short run with a total of only 3' altogether. any ideas on how i can pull this off? can i perhaps elevate it a little bit more, above the
fume hood to allow the ducting to turn more gradually. would 2 x 45 degree angles separated by 1' of ducting be better than 1 x 90 angle which, from
what i read, would kill the blower's vacuum within the fume hood
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EmmisonJ
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maybe mount it up further to allow the ducting to be as straight as possible and angle it, mount the blower directly up against the wall. it would
probably still need a small angle or two of some sort, perhaps a 45 degree angle at the bottom connecting to the fume hood and another 45 degree angle
connecting to the blower.
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EmmisonJ
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this is just for those tuning in who are as knowledgeable on this as i am. i found this piece of information regarding blowers that states why you
need an adapter plate for direct-drive blowers.
taken from http://www.alpinehomeair.com/viewcategory.cfm?categoryID=86
| Quote: | | Blower housings and blower wheels come it two types: direct drive and belt drive. Direct drive means the motor is mounted inside the blower housing
and the motor shaft connects directly into the center of the blower wheel. Belt drive means the motor mounts on the outside of the blower housing, has
a pulley on the motor shaft and a pulley on the blower wheel, and a belt to connect the two pulleys together. |
so i'm down to 2 final issues i'm working out, one having to do with plate adapters for direct-drive blowers and the other regarding my ducting/air
flow/mounting problem so i was wondering
1) does anyone have a link pointing to adapter plates for direct-drive blowers, where i can buy them? or can i just basically call up
grainger/dayton directly and ask? tried googling quite a bit and found a lot of webpages for parts from distributors but none of them appeared to be
what i would be looking for if i go with a direct-drive model.
2) regarding the airflow problem (just bumping my 2 above posts) are 2 x 45 degree turns like in the bottom pic better than the 1 x 90 degree turn
like in the top pic? i know you guys say that a 90 degree turn in ducting is going to kill air flow but if it's such a short run like in the top pic
would it really hurt it? better to do a long run at a slant like the bottom pic?
i suppose putting it at the top of the back of the fume hood like this guy did with his paint spray booth is going to kill the dynamic of the fume
hood's air flow with the baffles huh? because if not then it would be much better than me introducting any ducting curves in front of the blower (but
i guess a curve after the blower like in this link is ok because that's the pressurized side?)
http://sluggyjunx.com/workshop/carpentry/2005_01_23-spray_bo...
otherwise i think i'm stuck needing a 90 degree elbow and adopt a "remote blower" setup like in page 12 of the labconco attached pdf. these guys say
what magpie's theory was which is to keep the ducting under vacuum, although my run is such a short one that i don't think it'd matter much in my
case. they show under "integral motor/blowers" on page 13-14 the setup i was thinking of originally but i don't want to risk misaligning the bearings
or anything because who knows what type of blower labconco is using, i'm sure they have ones that are meant to be mounted like that and not just some
oddball blower like i'm going to have. so is the remote blower setup with the 90 degree elbow really so bad, it appears my options are limited.
thanks again guys, all of you are great. i'm really a lot further along at understanding this than i was just a week ago.
[Edited on 12-2-2009 by EmmisonJ]
Attachment: fhpdf.pdf (322kB)
This file has been downloaded 615 times
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watson.fawkes
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| Quote: | Originally posted by EmmisonJ
1) does anyone have a link pointing to adapter plates for direct-drive blowers [...]
2) regarding the airflow problem (just bumping my 2 above posts) are 2 x 45 degree turns like in the bottom pic better than the 1 x 90 degree turn
like in the top pic? |
1) When I initially used the term "adapter plate", I was talking about a way of sealing
a duct onto the input side of the particular fan I posted. That fan had no stub for affixing an input duct, and so one would have to be fashioned. I
envisioned a plate with a hole in it, sealed with silicone caulk.
As for a motor mounting plate, the easiest thing is a hinge and a piece of plywood. Orient the motor so that its own weight tensions the belt. You
might need a spring, in addition, for adequate tension.
2) There are tables available of the static pressure drop for different duct sizes and shapes. There are two rules of thumb, though, that is most of
what you need. (a) The larger the cross section, the lower the loss. (b) The slower the turning of the bend, the lower the loss. Using wide-sweep
fittings is always preferable.
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EmmisonJ
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| Quote: | Originally posted by watson.fawkes
1) When I initially used the term "adapter plate", I was talking about a way of sealing a duct onto the input side of the particular fan I posted.
That fan had no stub for affixing an input duct, and so one would have to be fashioned. I envisioned a plate with a hole in it, sealed with silicone
caulk.
As for a motor mounting plate, the easiest thing is a hinge and a piece of plywood. Orient the motor so that its own weight tensions the belt. You
might need a spring, in addition, for adequate tension.
2) There are tables available of the static pressure drop for different duct sizes and shapes. There are two rules of thumb, though, that is most of
what you need. (a) The larger the cross section, the lower the loss. (b) The slower the turning of the bend, the lower the loss. Using wide-sweep
fittings is always preferable. |
ah, thanks that clears up a lot and, i believe, only leaves me with one more question:
so i'm wondering, do these dayton direct-drive blowers need their motor relocated? the direct-drive models that use a rod to turn the fan like the
one in the ebay link watson_fawkes provided and the pic attached (some random dayton model i found that had a good side view) as opposed to a
belt-driven model like magpie's where the motor is typically on the side? i just can't tell if the motor on these direct-drive models are open to
fumes or not. i imagine there must be at least a small hole where the rod would be located and connect between the motor and fan but am not sure if
that would present a problem or not as i am unfamiliar with blowers.
i'd really like to get a direct-drive blower to save about $200, but will just continue saving money for a belt-drive model if there's no way to
separate the motor entirely from the fume path on direct-driven models.
[Edited on 16-2-2009 by EmmisonJ]
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Phosphor-ing
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Pretty much any direct drive motor will be exposed to the fumes. Belt drives are preferable. Unless you can afford a new blower every so often.
"The nine most terrifying words in the English language are: 'I'm from the government and I'm here to help.'" -Ronald Reagan
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EmmisonJ
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oh ok thanks, i'll just have to save up for a bit longer and get a belt-driven 
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Magpie
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Although I have not examined a direct drive centrifugal blower like you show in your picture I suspect that there is just a small hole in the housing
sufficient to permit the shaft to connect to the fan wheel. Also, when this fan is in operation that area will be under vacuum (it's in the center of
a centriguge) and so the motor will not be exposed to corrosive fumes/gases. In my opinion that cheaper blower should work OK in reference to motor
corrosion resistance.
Now whether or not you have it properly sized for your application is another question.
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EmmisonJ
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not much of an update yet. i put on a couple coats of epoxy paint as recommended in my other fumehood related thread and ordered a belt-driven blower
and am waiting for it to come in which gives me time to put in my baffles and sash.
Magpie,
in this thread (http://www.sciencemadness.org/talk/viewthread.php?tid=11145) you gave the measurements of the gaps between your baffles. i was wondering how tall
your bottom baffle is (the actual bottom baffle itself)?
[Edited on 4-3-2009 by EmmisonJ]
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Magpie
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| Quote: |
i was wondering how tall your bottom baffle is (the actual bottom baffle itself)?
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It's 13 inches.
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Aristocles
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I purchased this from ebay, and await its delivery:
http://i5.ebayimg.com/06/i/001/35/27/ffdb_1.JPG
http://i20.ebayimg.com/02/i/001/35/28/0219_1.JPG
I got it for 20 USD, so it's not the end of the world if I have to toss it... the guy guarantees it to run well, etc. but I'll do some cleaning,
oiling, and slap some paint on.
I have bought it rather in the dark and await its arrival to send some specs to Magpie for his opinion, re: viability. I fear that although belt
driven and motor qua motor is out of the way of noxious fumes, the bearings/shaft are not... I hope it's not a throw away...
Good and informative thread, thanks to all!
KentuckyPWRLFTR... yeah, self signed 
\"This is our purpose: to make as meaningful as possible this life that has been bestowed upon us; to live in such a way that we may be proud of
ourselves; to act in such a way that some part of us lives on.\"
-Spengler
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volfrahm
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Great thread, really cleared up a few lingering questions I had about blowers.
It sounds like the case, but I'd really like to put a fine point on it: in the case of the belt-driven squirrel cage blowers, are these effectively
"explosionproof" with regard to vapors coming from within the fumehood? What if I'm evapping diethyl ether all day (for example, of course)?
Does anyone have a good (non-ebay) source for a truly explosionproof blower?
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EmmisonJ
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got the same blower as magpie, did a lot of looking around and it seemed to be the best bang for the buck as far as belt-driven blowers. the manual
that came with it is a safety manual and doesn't have any instructions regarding installation. i spent the past hour searching online for some type
of manual or documentation to help me out and the best thing i could find is this:
http://www.lauparts.com/catalog/servefile.aspx?id=2015
where did you guys get your materials to install your blowers? i can't even figure out how to get a power source to it. i'm definitely no tim
taylor, in fact assembling a grill usually entails me swearing for an hour, throwing something, then finishing it the next day. my wife thinks it's a
riot but, me, not so much 
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Magpie
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Since you say you know nothing about how I will give some very basic direction:
1. I used 8" irrigation PVC pipe for ducting. The outside diameter (OD) of this pipe is less than 9". The inlet of the blower is 9". To make a
seal here I bought a 2" strip of rubber (probably EPDM) of an appropriate thickness and placed around the pipe end. Probably glued it to the PVC pipe
with silicone. This closed the gap between the inlet of the fan and the OD of the pipe. I just shoved the pipe into the inlet. My pipe and blower
are well supported so they don't move out of position.
2. The outlet of the fan, which is rectangular, is shoved into my custom made outlet plenum (sheet metal box) that adapts the blower to the outlet
grate built into my garage wall. Again, everything is well supported so nothing moves out of position. The plenum is mounted to the garage wall with
screws.
3. The motor comes mounted on the blower. I took it off and mounted it on the same piece of 3/4" plywood that I mounted the blower on. Everything
on the plywood is mounted with 1/4" bolts, locked by double nuts or lock nuts.
You have several options for positioning the blower with respect to its mounting base. Choose the one that is appropriate to your configuration. Be
sure the motor is properly aligned with the blower (pulleys in the same plane). Tension the belt so that it deflects about 1/2" when you press on it.
4. Bring a #14, 3-wire insulated cable to the motor box and attached the white and black wires as indicated. Also attach the green (or bare) wire as
indicated. This is the ground wire.
The wire can come directly from a 120VAC, 15-amp circuit breaker in your service entrance. Or you can tee into an existing wire of the same type, if
there is adequate excess amp capacity to do so. Add up your existing amp loading and the motor amp load and see if it is within your circuit
breaker's capacity.
You will need to install a switch (like a light switch) in the cable also.
If you feel that this electrical work is beyond your capabilities by all means get qualified help. Nothing here is worth burning your house down or
killing someone by electrical shock.
[Edited on 11-3-2009 by Magpie]
[Edited on 11-3-2009 by Magpie]
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EmmisonJ
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thanks magpie, you've really gone above and beyond!
mine actually came with the blower and motor shipped separately, looks like it's in need of a spacer between the blower motor and its pulley. i'm
going to call grainger when i get home and work all that out minor assembly stuff out with them.
but as far as the electrical side goes, it sounds like you install it just like you would a ceiling fan and make sure it's 15 amp? i'll ask grainger
about that too because i don't see any wires or anything coming outside the housing. i'll give grainger a ring later today and post back what they
say.
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EmmisonJ
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have the assembly figured out thanks to grainger and he explained the power to me:
terminal 4 (where blue is - bring in common white)
terminal 1 (where line 2 is - bring in power)
unfortunately i have no idea how to do this but wanted to research what was involved before deciding if i can do it myself or not. i know so little
about this that i'm not sure how to ask a question about what it is i'm trying to pull off. i was thinking it was just going to be a standard
interface to go into an ac outlet. is there some type of brief overview or 'how to' that somebody might be able to link over that would help me get
an idea of how to get this blower motor hooked up to standard ac? excuse my ignorance, first time home owner here and a very unhandy one at that.
but with some proper reading i'm sure i can pull it off.
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watson.fawkes
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| Quote: | Originally posted by EmmisonJ
have the assembly figured out thanks to grainger and he explained the power to me:
terminal 4 (where blue is - bring in common white)
terminal 1 (where line 2 is - bring in power) |
If it's the same as motor's I've powered, there are screw
terminals underneath a removable plate. Just screw the wires down. Generally there's also a hole to affix flexible conduit onto. Use it; it will make
your life better later.
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EmmisonJ
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| Quote: | Originally posted by watson.fawkes
If it's the same as motor's I've powered, there are screw terminals underneath a removable plate. Just screw the wires down. Generally there's also a
hole to affix flexible conduit onto. Use it; it will make your life better later. |
yeah i was able to find that and mine will need a connector crimped onto the wires as opposed to having a screw. but what i was curious about was the
electrical part of it, is there any easy way to run those 2 wires i need for power? what in my house am i going to need to tap into, to run those 2
wires the blower motor will need? i used to do car stereo way back in my younger years but have never done anything in a house aside from the 2
ceiling fans i mounted which already had the wires run, so i never had to run wires in a house before.
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watson.fawkes
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| Quote: | Originally posted by EmmisonJ
yeah i was able to find that and mine will need a connector crimped onto the wires as opposed to having a screw. but what i was curious about was the
electrical part of it, is there any easy way to run those 2 wires i need for power? |
For the motor side,
install a standard 3-prong plug. Near the motor (<= 6ft), install an branch circuit. Put this branch circuit on an ordinary light switch. With this
advice, I'm assuming you have a fairly small motor (<= 2 HP). You have find instructions for running branch circuits in any of the electrical books
at your local big box home store.
You could direct-wire it in, but this solution is a more conservative answer to the problem. You can install the outlet first, and test it, and make
sure it's safe, all before plugging in the fan. Later, if you get more ambitious, you could also use a separate contactor (i.e. motor relay),
industrial start and stop switches, dedicated low-amperage circuit breakers, an operating lamp and a whole lot else. Start with a simple switched
outlet, though; it should get you started just fine.
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Magpie
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Since you want to do this the easiet way possible I second watson's recommendation. I will amplify abit:
1. If you have a standard 120VAC wall outlet (a "duplex") replace that with a switched single 120VAC outlet.
2. Get a flexible 3-wire cord, #14, and attach it to a 3-pronged plug. This cord can be bought by the foot. Get the minimum length needed.
3. Attach the other end of the cord to the terminals in the motor box per Grainger.
Home Depot will have all the parts you need.
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EmmisonJ
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...and you guys even broke it down into terms i can understand, thanks guys! i will post back the results
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EmmisonJ
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one more question about the wiring of the blower motor:
the blower motor came with a green/yellow wire grounded to the chassis of the blower motor. the #14-3 cable has a white, black, and green. i know
what terminals the white/black go to but was wondering if i should disregard the green on the #14-3 or should i ground it to the same exact place the
blower motor's ground is?
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Magpie
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Ground the green wire to the same place as the motor ground.
Grounding is an important safety feature, never ignore it. This is how it works: If your hot wire (the black one) should accidentaly come in contact
with the metal case of the motor it will short to ground and pop open the circuit breaker in your service entrance. This prevents you from an
accidental shock when touching the motor casing.
[Edited on 19-3-2009 by Magpie]
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EmmisonJ
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Magpie, did you put any type of spacer between the belt pulley on your blower and the housing? likewise for the blower motor, any spacer between the
pulley and the actual blower motor itself?
p.s. i called grainger and they said to just leave a little space between the pulley and the housing when you tighten it down, that you don't really
need any type of spacer, just leave an open space there if necessary. i guess i'm concerned with it sliding back up against the housing but if you
tighten it down tight enough then that's really a non-issue per grainer. i trust grainger's tech support but i don't trust my ability to adequately
describe the question to them because i'm such a newbie with this i don't know the terminology to correctly describe the situation, so i'm curious
what somebody else with the same model ended up doing.
thanks as always you guys are a great help.
[Edited on 4-5-2009 by EmmisonJ]
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Magpie
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I don't see where this matters. My pulleys are 1/4"-1/2" from the blower or motor, respectively. Just make sure the pulleys are aligned with each
other and the belt is properly tensioned. The rule-of-thumb on tensioning is 1/2" of deflection using moderate finger pressure. Actually, the way
mine is set up the weight of the motor automatically tensions the belt. I assume yours will be the same.
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