What is the deal with my range hood?
August 30, 2013 4:52 AM Subscribe
I bought what I thought was a more powerful range hood but it moves very little air at all.
After having one of those low power range hoods that can either vent back into the kitchen, or up into duct work I purchased what I thought was a much more powerful range hood (fan).
Specifically, it is this model from NuTone. I don't know who writes the reviews for products on websites but if you go by what is on their site and the HomeDepot site for the range hood I feel like I have a different fan entirely.
The fan moves so little air that condensation from steam (say when boiling water for pasta or canning) forms on the underside of the unit that drips back down onto the range. It's nasty and I have to wipe it down before it gets into the food.
Before you ask, I have tried this thing in every conceivable configuration: I had it ducted directly outside, then after putting a metal roof on our house I vented it outside under an eave, as a last resort just to see if ANY air was coming out of it, I vented it into my attic directly with the shortest possible run of duct (about 4'). (No, it's not like this now, I know not to do this.) None of these configurations made any difference.
How weak is it? When steam rises from a pot of boiling water, it actually goes around or in front of the fan part of the range hood! It's like the fan is making fun of me.."haha..you think we're removing that air?..sucker."...
Also, I do what I call the "Tissue test". Take the lightest piece of tissue paper or kleenex you can find and hold it near the back of any fan (box fan, desk fan etc). The airflow should pull the tissue toward the fan right? Well on this range hood you can put the tissue right on the intake where the grills are, and it does not get pulled towards it or stick to it like you think it should! (Yes, the grilles are clean, btw). I think the old cheapee unit I had worked better!
What is going on? It certainly is loud enough and and the blower (squirrel cage type thing) spins fast enough, but it does not move air. I hate it hate it hate it hate it. I paid $400 or so for this fan and thought it was expensive...I don't have the funds for a $1,000+ commercial unit...but is that what I need?
After having one of those low power range hoods that can either vent back into the kitchen, or up into duct work I purchased what I thought was a much more powerful range hood (fan).
Specifically, it is this model from NuTone. I don't know who writes the reviews for products on websites but if you go by what is on their site and the HomeDepot site for the range hood I feel like I have a different fan entirely.
The fan moves so little air that condensation from steam (say when boiling water for pasta or canning) forms on the underside of the unit that drips back down onto the range. It's nasty and I have to wipe it down before it gets into the food.
Before you ask, I have tried this thing in every conceivable configuration: I had it ducted directly outside, then after putting a metal roof on our house I vented it outside under an eave, as a last resort just to see if ANY air was coming out of it, I vented it into my attic directly with the shortest possible run of duct (about 4'). (No, it's not like this now, I know not to do this.) None of these configurations made any difference.
How weak is it? When steam rises from a pot of boiling water, it actually goes around or in front of the fan part of the range hood! It's like the fan is making fun of me.."haha..you think we're removing that air?..sucker."...
Also, I do what I call the "Tissue test". Take the lightest piece of tissue paper or kleenex you can find and hold it near the back of any fan (box fan, desk fan etc). The airflow should pull the tissue toward the fan right? Well on this range hood you can put the tissue right on the intake where the grills are, and it does not get pulled towards it or stick to it like you think it should! (Yes, the grilles are clean, btw). I think the old cheapee unit I had worked better!
What is going on? It certainly is loud enough and and the blower (squirrel cage type thing) spins fast enough, but it does not move air. I hate it hate it hate it hate it. I paid $400 or so for this fan and thought it was expensive...I don't have the funds for a $1,000+ commercial unit...but is that what I need?
Yeah, this shouldn't happen. Is there an obstruction in the ductwork? If the fan is turning but air isn't flowing, maybe there is no place for it to go?
posted by Sublimity at 5:08 AM on August 30, 2013
posted by Sublimity at 5:08 AM on August 30, 2013
Response by poster: It does have a damper. The flap opens when the fan comes on (and you can hear it close when the fan is shut off). However, I can go in the attic and see light down into the kitchen so I know it's open, but if I put my hand above the opening with no ductwork when the fan is on "high"the airflow is weak weak weak.
posted by dukes909 at 5:14 AM on August 30, 2013
posted by dukes909 at 5:14 AM on August 30, 2013
Have you tried opening a window when running the fan to see if the airflow improves?
It seems improbable, but I've heard anecdotes about very tight houses (especially new construction) where there isn't enough inflowing air to replace what you're trying to exhaust, so the fan just spins without really doing anything.
posted by RonButNotStupid at 5:15 AM on August 30, 2013
It seems improbable, but I've heard anecdotes about very tight houses (especially new construction) where there isn't enough inflowing air to replace what you're trying to exhaust, so the fan just spins without really doing anything.
posted by RonButNotStupid at 5:15 AM on August 30, 2013
could the power wiring be reversed? maybe the fan is just spinning in the wrong direction. try reversing the black and white power connections (with the breaker switched off of course)
posted by maximum sensing at 5:18 AM on August 30, 2013
posted by maximum sensing at 5:18 AM on August 30, 2013
Response by poster: Yes, I've tried it with a window open,..no difference. :( Also, it doesn't matter what season it is; I've had this thing long enough to go through all seasons a couple of times over...dry winter days and hot humid summer days - makes no difference.
posted by dukes909 at 5:19 AM on August 30, 2013
posted by dukes909 at 5:19 AM on August 30, 2013
I don't think this model moves enough air for the 'house too tight' problem to be a factor.
The motors in these things do not spin the other way when the wiring is reversed.
OP, have you double-checked the orientation of the blower?
posted by jon1270 at 5:20 AM on August 30, 2013
The motors in these things do not spin the other way when the wiring is reversed.
OP, have you double-checked the orientation of the blower?
posted by jon1270 at 5:20 AM on August 30, 2013
Response by poster: I haven't checked the wiring, but if it was blowing in reverse..wouldn't I feel air coming out of the grilles? I will check it tonight though just to be sure!
posted by dukes909 at 5:20 AM on August 30, 2013
posted by dukes909 at 5:20 AM on August 30, 2013
Response by poster: I haven't double checked the orientation of the blower this morning, but according to the manual it ships in a default mode of UP (into the attic). Also, if it was oriented wrong, how would it be opening the damper? I will check to be sure...I'm at the office right now.
posted by dukes909 at 5:22 AM on August 30, 2013
posted by dukes909 at 5:22 AM on August 30, 2013
Are you sure the fans have been installed correctly and are turning in the right direction? If it's the kind of fan that looks like a wheel, and you run it backwards it won't move air in the opposite direction (which you would immediately realize), but might work very inefficiently.
posted by Dr Dracator at 5:25 AM on August 30, 2013
posted by Dr Dracator at 5:25 AM on August 30, 2013
if it was oriented wrong, how would it be opening the damper?
I don't have a good answer for you there. If it were me, I'd pull the thing off the wall, wire it to an extension cord and plug it in for a test while disconnected from any ductwork. Chances are the problem is something really simple, but you can't see what's going on while it's installed.
posted by jon1270 at 5:26 AM on August 30, 2013 [1 favorite]
I don't have a good answer for you there. If it were me, I'd pull the thing off the wall, wire it to an extension cord and plug it in for a test while disconnected from any ductwork. Chances are the problem is something really simple, but you can't see what's going on while it's installed.
posted by jon1270 at 5:26 AM on August 30, 2013 [1 favorite]
Best answer: Your range hood should definitely pass the "tissue test". This means something is wrong. Range vents aren't complicated... they're basically just a fan connected to a duct. So: either the fan isn't pulling air for some reason, or the duct is blocked somewhere. (the duct could also be too long for the hood, but you said that even at 4ft it wasn't venting the stove) i.e. the vent wasn't installed correctly.
Did you install it yourself? It's possible that the unit shipped with the duct stub blocked for shipment. It also might have a backflow valve (essentially a flapper in the duct which only opens out) which is either locked or stuck shut for some reason.
posted by ennui.bz at 5:27 AM on August 30, 2013
Did you install it yourself? It's possible that the unit shipped with the duct stub blocked for shipment. It also might have a backflow valve (essentially a flapper in the duct which only opens out) which is either locked or stuck shut for some reason.
posted by ennui.bz at 5:27 AM on August 30, 2013
A couple of the reviews say:
The only con is low fan speed...it doesn't do much. The high fan speed makes up for it!
There are 2 speed of exhaust fan. Speed 1 isn't very strong but speed 2 awesome. It's a little bit loud, but it does the work.
So stupid question but: have you tried both the low and high fan settings?
posted by EndsOfInvention at 5:27 AM on August 30, 2013
The only con is low fan speed...it doesn't do much. The high fan speed makes up for it!
There are 2 speed of exhaust fan. Speed 1 isn't very strong but speed 2 awesome. It's a little bit loud, but it does the work.
So stupid question but: have you tried both the low and high fan settings?
posted by EndsOfInvention at 5:27 AM on August 30, 2013
Response by poster: Yes, low speed does virtually nothing at all (but the reviews on the HD website say the same thing so that is a wash, I think).
posted by dukes909 at 5:28 AM on August 30, 2013
posted by dukes909 at 5:28 AM on August 30, 2013
Response by poster: I like the idea of taking it out completely and checking it while hooked up to an ext cord. I'll do that this weekend.
posted by dukes909 at 5:30 AM on August 30, 2013
posted by dukes909 at 5:30 AM on August 30, 2013
seconding this: It's possible that the unit shipped with the duct stub blocked for shipment.
posted by Gungho at 5:36 AM on August 30, 2013
posted by Gungho at 5:36 AM on August 30, 2013
Response by poster: I am 99.9% sure the duct stub is not blocked. I can see it open from in the attic looking down.
posted by dukes909 at 5:38 AM on August 30, 2013
posted by dukes909 at 5:38 AM on August 30, 2013
From what I can tell, there are two fans. Could one of them be backwards? That might be enough to open the damper, but not to, you know, actually do anything.
posted by supercres at 5:42 AM on August 30, 2013 [1 favorite]
posted by supercres at 5:42 AM on August 30, 2013 [1 favorite]
Response by poster: There are 2 fans...I never thought about one of them being backwards...I will check that too!
posted by dukes909 at 5:46 AM on August 30, 2013
posted by dukes909 at 5:46 AM on August 30, 2013
There's just one motor, with two mirror-image squirrel cages attached to it.
posted by jon1270 at 5:50 AM on August 30, 2013
posted by jon1270 at 5:50 AM on August 30, 2013
Response by poster: So there is no chance this thing is just poorly designed?
posted by dukes909 at 5:57 AM on August 30, 2013
posted by dukes909 at 5:57 AM on August 30, 2013
So there is no chance this thing is just poorly designed?
We can't know, but I think there's probably more going on than that.
posted by jon1270 at 6:05 AM on August 30, 2013
We can't know, but I think there's probably more going on than that.
posted by jon1270 at 6:05 AM on August 30, 2013
However, I can go in the attic and see light down into the kitchen so I know it's open
You can see light....is there any chance there's a protective plastic sheet blocking airflow? On a similar note, have you run this without the grease filter?
posted by RonButNotStupid at 6:15 AM on August 30, 2013
You can see light....is there any chance there's a protective plastic sheet blocking airflow? On a similar note, have you run this without the grease filter?
posted by RonButNotStupid at 6:15 AM on August 30, 2013
Response by poster: Yes, I've run it w/o grease grilles...no diff. Tissue is not pulled in. I mean, there is some airflow but dang, I think it should pull that tissue right in and whoosh..gone
posted by dukes909 at 6:18 AM on August 30, 2013
posted by dukes909 at 6:18 AM on August 30, 2013
Long shot, but if the squirrel cages are mirror-image, could they have given you two of the same part?
posted by supercres at 6:26 AM on August 30, 2013
posted by supercres at 6:26 AM on August 30, 2013
Response by poster: I don't know but I will check and take pictures of everything when I get it uninstalled.
posted by dukes909 at 6:38 AM on August 30, 2013
posted by dukes909 at 6:38 AM on August 30, 2013
I paid $400 or so for this fan and thought it was expensive...I don't have the funds for a $1,000+ commercial unit...but is that what I need?
Do you want a recommendation for one sort of in the middle if you wind up swapping it out? We have this and like it a lot. You could probably find it cheaper somewhere else - we paid 550 for it, off amazon, last year but it looks like there was a price bump. I'm sure you could get a better deal somewhere.
posted by A Terrible Llama at 7:21 AM on August 30, 2013
Do you want a recommendation for one sort of in the middle if you wind up swapping it out? We have this and like it a lot. You could probably find it cheaper somewhere else - we paid 550 for it, off amazon, last year but it looks like there was a price bump. I'm sure you could get a better deal somewhere.
posted by A Terrible Llama at 7:21 AM on August 30, 2013
I just read the reviews on that -- people complaining about the noise. I can't say they're wrong, but it gets the smoke/vapors out of the kitchen when it needs to and that's our biggest concern.
posted by A Terrible Llama at 7:23 AM on August 30, 2013
posted by A Terrible Llama at 7:23 AM on August 30, 2013
Response by poster: Thanks - that one is listed as 370CFM, and mine is supposed to be 440. So if yours works well there is something seriously wrong with mine!
posted by dukes909 at 7:38 AM on August 30, 2013
posted by dukes909 at 7:38 AM on August 30, 2013
The key spec to look at is the motor CFM rating: 440 CFM means that the motor pushes 440 cubic foot per minute of air through the fan. Professional hoods seem to start at about 1000 CFM.
How many CFM for a range hood do I REALLY need?
Your description matches my experience with a number of domestic range hoods, I don't know why people bother with them, I guess they give the 'look' of a professional kitchen but practically you might as well just open a window.
posted by Lanark at 8:47 AM on August 30, 2013
How many CFM for a range hood do I REALLY need?
Your description matches my experience with a number of domestic range hoods, I don't know why people bother with them, I guess they give the 'look' of a professional kitchen but practically you might as well just open a window.
posted by Lanark at 8:47 AM on August 30, 2013
Something to be aware of: depending on where you are, code may require a source of make-up air if your vent is greater than 400 CFM.
posted by Prawn at 9:05 AM on August 30, 2013
posted by Prawn at 9:05 AM on August 30, 2013
Response by poster: Oddly enough due the configuration of my range (one of those glass cooktops) I only ever use ONE "burner" at a time (usually the largest). Going by the calculations of the page you sent, I should be ok with a 440cfm but you think I am better off with something more like 1,200??...
posted by dukes909 at 9:12 AM on August 30, 2013
posted by dukes909 at 9:12 AM on August 30, 2013
You can also generate some visible smoke very easily by burning a little cotton rope or twine (like kitchen twine). Light it up, blow it out, and it'll continue to smoke for a few minutes while you try things out. Dunk it in water to stop the smoke. It's safe and easy to manage.
My thoughts are along snickerdoodle's problem-- the weird phenomenon of exhaust pressure, which is the resistance of the exhaust path that allows pressure to build up (not in a dangerous way) enough to neutralize the blowing of the fans.
posted by Sunburnt at 10:19 AM on August 30, 2013
My thoughts are along snickerdoodle's problem-- the weird phenomenon of exhaust pressure, which is the resistance of the exhaust path that allows pressure to build up (not in a dangerous way) enough to neutralize the blowing of the fans.
posted by Sunburnt at 10:19 AM on August 30, 2013
Your description matches my experience with a number of domestic range hoods, I don't know why people bother with them,
Maybe, but his has more CFM than mine, and mine is great even though the kitchen sits at a corner between two broad, open rooms and it's a rough place to be efficient. No kidding, because we're very nerdy, we routinely have conversations about what a great decision it was to have it installed (previously, the entire ventilation system was a ceiling fan. Not the kind that sucks up air, just like an actual fan hanging from the ceiling).
The only thing maybe noteworthy is that the pipe that vents the fumes is only maybe five or six feet long before it vents to the outside. If you stand outside when someone is cooking, the cooking smells are kind of overwhelming and I'm always imagining bears showing up.
It really sounds like something is meaningfully wrong with OPs fan. It sounds like a cheap desk fan would do more--that's really wrong, not just a little wrong.
posted by A Terrible Llama at 10:32 AM on August 30, 2013
Maybe, but his has more CFM than mine, and mine is great even though the kitchen sits at a corner between two broad, open rooms and it's a rough place to be efficient. No kidding, because we're very nerdy, we routinely have conversations about what a great decision it was to have it installed (previously, the entire ventilation system was a ceiling fan. Not the kind that sucks up air, just like an actual fan hanging from the ceiling).
The only thing maybe noteworthy is that the pipe that vents the fumes is only maybe five or six feet long before it vents to the outside. If you stand outside when someone is cooking, the cooking smells are kind of overwhelming and I'm always imagining bears showing up.
It really sounds like something is meaningfully wrong with OPs fan. It sounds like a cheap desk fan would do more--that's really wrong, not just a little wrong.
posted by A Terrible Llama at 10:32 AM on August 30, 2013
I agree. I think something is meaningfully wrong.
I recently was speccing a range hood for a project I was designing and had an interesting conversation with the contractor. Basically, anything over a certain CFM requires makeup air. You can read a rather extensive article about the challenges of high CFM range hoods and providing makeup air. One of the challenges that I'm more acutely aware of is that those fans (especially in the more affordable price points) can be pretty loud. To deal with this, the contractor had taken to installing her fans remotely, basically out near where it exhausts at the roofline -- it'll pull through the duct and exhaust just fine (search for remote blower vs. local blower). Additionally, the contractor installs a bit of "flexible ducting" between the fan and the hood to further reduce vibration. End result (one hopes) -- a virtually silent giant sucking beast!
Anyway, I thought this was a great idea and might be something to consider if you decide to scrap your whole system and make another go at it.
posted by amanda at 11:14 AM on August 30, 2013 [1 favorite]
I recently was speccing a range hood for a project I was designing and had an interesting conversation with the contractor. Basically, anything over a certain CFM requires makeup air. You can read a rather extensive article about the challenges of high CFM range hoods and providing makeup air. One of the challenges that I'm more acutely aware of is that those fans (especially in the more affordable price points) can be pretty loud. To deal with this, the contractor had taken to installing her fans remotely, basically out near where it exhausts at the roofline -- it'll pull through the duct and exhaust just fine (search for remote blower vs. local blower). Additionally, the contractor installs a bit of "flexible ducting" between the fan and the hood to further reduce vibration. End result (one hopes) -- a virtually silent giant sucking beast!
Anyway, I thought this was a great idea and might be something to consider if you decide to scrap your whole system and make another go at it.
posted by amanda at 11:14 AM on August 30, 2013 [1 favorite]
http://www.nutone.com/
Need Assistance? In U.S.A. Call: 1-888-336-3948
Technical Support: 1-888-336-6151
In Canada Call: 1-888-882-7626
- See more at: http://www.nutone.com/#sthash.qnzmyU7W.dpuf
posted by theora55 at 11:26 AM on August 30, 2013
Need Assistance? In U.S.A. Call: 1-888-336-3948
Technical Support: 1-888-336-6151
In Canada Call: 1-888-882-7626
- See more at: http://www.nutone.com/#sthash.qnzmyU7W.dpuf
posted by theora55 at 11:26 AM on August 30, 2013
Response by poster: ok ok I am going to post back here after getting it out and apart tonight or tomorrow. What I really was trying to find out here was whether this fan was seriously underpowered hence the (lack of) results. It sounds like the consensus here is that it is not underpowered and should work.
FWIW, the duct coming out of this thing is 8" piece round like this connected to a transition piece like this that sits connects to the damper.
posted by dukes909 at 11:38 AM on August 30, 2013
FWIW, the duct coming out of this thing is 8" piece round like this connected to a transition piece like this that sits connects to the damper.
posted by dukes909 at 11:38 AM on August 30, 2013
It sounds like something is wrong with the unit you bought, return or exchange it at Home Depot or call Nutone.
You could also try emailing or writing Nutone with a link to your question here, and ask what they can do for you.
posted by yohko at 2:00 PM on August 30, 2013
You could also try emailing or writing Nutone with a link to your question here, and ask what they can do for you.
posted by yohko at 2:00 PM on August 30, 2013
Response by poster: For those still playing at home I have resolved this last night.
I took the grilles off first to make sure they were clean. Then checked the orientation of the blower - it was correct - blowing up. I made sure the damper was opening while running - it was. I took the blower out anyway just to make sure nothing was between it and the damper - there wasn't. Then I checked the operation of the damper by hand..it opened. HOWEVER, it was only opening 1/4 of the way before getting stuck on the transition piece of sheet metal (that I linked to above). Apparently there was not enough rectangular section before the transition to the circular part and the damper could not open fully as the corners were getting stuck. I was going to bend the corners but just decided to take it out completely to test... Today I made pasta and the steam was sucked away wonderfully! Thanks all.
posted by dukes909 at 1:37 PM on August 31, 2013 [3 favorites]
I took the grilles off first to make sure they were clean. Then checked the orientation of the blower - it was correct - blowing up. I made sure the damper was opening while running - it was. I took the blower out anyway just to make sure nothing was between it and the damper - there wasn't. Then I checked the operation of the damper by hand..it opened. HOWEVER, it was only opening 1/4 of the way before getting stuck on the transition piece of sheet metal (that I linked to above). Apparently there was not enough rectangular section before the transition to the circular part and the damper could not open fully as the corners were getting stuck. I was going to bend the corners but just decided to take it out completely to test... Today I made pasta and the steam was sucked away wonderfully! Thanks all.
posted by dukes909 at 1:37 PM on August 31, 2013 [3 favorites]
This thread is closed to new comments.
posted by jon1270 at 5:08 AM on August 30, 2013