Range hood

[Dryden]

Hi folks!  We are redoing our kitchen and while we know what we're doing most everywhere, it turns out we need to upgrade our existing range hood to something new and we know nothing whatsoever about them.  We're in an apartment, so it needs to be a non-venting hood.

 

Does anyone have one they really like (and why?)  Price not an object here at all.  It's for a 36" range if that matters at all.

 

Thanks!

[ElsieD]

We have recently purchased a new range hood and it is made by Broan.  We too live in an apartment but our hood does vent to outside.  We like it very much;  it has 3 fan speeds and three light settings.  One thing i discovered after i installed it was that it sticks out more into the kitchen than the one that was there.  The part that sticks out is my height and every now and again I whack my head on it.  You may want to keep that in mind.

[Yiannos]

I just went through the same thing as you, there are so many out there my eyes would just glaze over every time I began searching. Eventually what I learned is that unless you are going with a custom or commercial unit they are all very similar. Not sure how big your kitchen/home is, but do a little reading to help calculate the approximate CFM rating first, and then I would start digging around online for shops that carry them. ABT and AJ Madison come to mind, much more variety than the usual Home Depot or Lowe's offerings. Find a style that you like, most, if not already set up for non-venting, will offer some kind of conversion kit. If money is really no object Vent-a-Hood makes amazing units, but you will pay. I ended up buying a Zephyr from AJ Madison I think it was, the name came up a few times with some positive experiences and they had a style and size that we liked so that was all it really took. Broan are also good like @ElsieD
mentioned, it's the one we just removed and strangely we had the same experience as her re: it sticking out a tiny bit far. It was also mounted a little low in our kitchen so that might have been it, just weird to hear the exact same complaint from someone else.

[chromedome]

If at all possible, try to hear one in operation. I've lived in rentals where I flat-out wouldn't use the hood for anything short of dire necessity because of the resultant noise level.

[ElsieD]

Just now, chromedome said:

If at all possible, try to hear one in operation. I've lived in rentals where I flat-out wouldn't use the hood for anything short of dire necessity because of the resultant noise level.

 

Yes, that's why we got one with 3 fan speeds.  It is only ever on high when, say, i am searing a steak, and that only lasts for a few minutes.  The rest of the time we find speed #1 does the job.

[Margaret Pilgrim]

We have had a KOBE for 5+ years.    It's good.   But the effectiveness and owner satisfaction with range hoods depends on how one cooks.   

I turn out three meals a day, 7, cooking on high heat several times a day.    Although I put the louvers in the dishwasher pretty regularly, schmutz accumulates inside the hood.  In theory, one should wipe down the interior of one's hood once a day when in regular use.   I don't.

[pastameshugana]

We installed this off brand one I got at amazon five years ago. Not a blip or a glitch. The high fan setting is noticeable but not obnoxious, and it’s powerful enough to conquer frying bacon or searing steaks. 

[weinoo]

 

 

I like mine, probably chosen as much for its looks as its efficacy. You know, matching and all. In an apartment, recirculating, so it does as much as a recirculating hood can do.

 

The grease filters get really greasy and go in the dishwasher once a week. The inner charcoal filters theoretically get replaced on a 6 month basis. In general, it does more than I hoped, but not as much as I wished for (which would be venting to the outside).

 

There was a lot of hand-wringing and a lot of research which went into this purchase, and the ultimate decision to not try to make a run out the window, which is allowed but would've been an engineering nightmare.

 

AJ Madison is OK - except for how annoying they are when you go in person...an amazing selection of product for sure.

Edited September 1, 2020 by weinoo (log)

[dcarch]

I don't believe range hood specifications. They are fake numbers.

Do you have a leaf blower? A powerful leaf blower with 400 CFM spec blowers a lot of air and makes a lot of noise.  Can a kitchen hood with 600 CFM to 900 CFM make not much noise?

Range hoods to keep the motor noise down mostly use induction motors which run inherently at low speed, and the path to exhaust the air restrict the diameter of the duct.

The length of the duct and any bends in the exhaust duct created air turbulent back pressure, and  filters can restrict air flow.

 

I would be surprised in actual use, a typical hood can exhaust more than 200 CFM. 

 

dcarch

Edited September 1, 2020 by dcarch (log)

[gfweb]

 

The type of stove is a consideration. An induction range has little air upflow because it doesn't waste a lot of heat, that makes the fan have to suck harder just t o get the smoke up into the hood.

 

The specs for vent mounting  height are all low if you are over about 5'8". One's head gets in the way at the rated height . Consider this when picking the fan power...the manufacturer may be citing efficacy at a lower than desirable mounting height.

 

We have a vented Vent-a-hood.  Its great.

 

 

[Dryden]

Thanks everybody!

[TicTac]

If you have a strong range, do not skimp on the hood!

 

Though I am not sure the brand (the logo is a cool looking 'S') ours has 2 fans (I believe they are either 6" or 8") and it is an absolute BEAST. 

 

If you can, find one with more than one fan and as big as you can fit/afford!

 

 

[dcarch]

The quantity of exhaust air is determined by the size of the duct and the air pressure of the fan.

 

If the duct size is only big enough for one fan, then it make no difference how many fans you have, 2, 3, 50, 100 fans will give you the same CFM of exhaust air.

 

As long as the fan size is the same, having more fans will not increase air pressure, therefore CFM.

 

dcarch

[KennethT]

1 hour ago, dcarch said:

The quantity of exhaust air is determined by the size of the duct and the air pressure of the fan.

 

If the duct size is only big enough for one fan, then it make no difference how many fans you have, 2, 3, 50, 100 fans will give you the same CFM of exhaust air.

 

As long as the fan size is the same, having more fans will not increase air pressure, therefore CFM.

 

dcarch

I don't know if that's completely true, depending on the fan arrangement.  I think if there are 2 fans in a push/pull arrangement (one at the hood pushing, and one at the final exhaust pulling) you might get more CFM since the extra fan will help compensate for the losses created by elbows/turbulence/etc.  That's my theory - I have no proof...

[gfweb]

1 hour ago, dcarch said:

The quantity of exhaust air is determined by the size of the duct and the air pressure of the fan.

 

  And also the length of the duct which increases drag.

[TicTac]

1 hour ago, dcarch said:

The quantity of exhaust air is determined by the size of the duct and the air pressure of the fan.

 

If the duct size is only big enough for one fan, then it make no difference how many fans you have, 2, 3, 50, 100 fans will give you the same CFM of exhaust air.

 

As long as the fan size is the same, having more fans will not increase air pressure, therefore CFM.

 

dcarch

 

While I cannot comment on the science behind it, I can tell you that I recall my contractor commenting on how large the ducts and exhaust holes were. 

 

I can also tell you that on the highest setting, this thing roars like a jet engine and no smoke is going anywhere but OUTSIDE!

 

The only downside of this setup is that believe it or not, these fans are so strong they are pulling the oil/fat onto the fans themselves and past the industrial grade grates.

 

Kind of scares me, eventually the build-up will be too much, no idea where to begin with cleaning those beasts....

 

 

[dcarch]

2 hours ago, KennethT said:

I don't know if that's completely true, depending on the fan arrangement.  I think if there are 2 fans in a push/pull arrangement (one at the hood pushing, and one at the final exhaust pulling) you might get more CFM since the extra fan will help compensate for the losses created by elbows/turbulence/etc.  That's my theory - I have no proof...

 

You are absolutely correct with universal motors and some brushless motors, their speed is determined by voltage, but induction motors are synchronous motors. They are more or less constant speed motors determine by 60 Hz line frequency. The pushing fan is not going to make the fan speed higher.

 

With very restricted and long running duct systems, you can increase CFM by adding in-line booster fan.

 

dcarch

 

[KennethT]

19 hours ago, dcarch said:

 

You are absolutely correct with universal motors and some brushless motors, their speed is determined by voltage, but induction motors are synchronous motors. They are more or less constant speed motors determine by 60 Hz line frequency. The pushing fan is not going to make the fan speed higher.

 

With very restricted and long running duct systems, you can increase CFM by adding in-line booster fan.

 

dcarch

 

I actually wasn't thinking about making the push motor go faster - The pull motor creates negative pressure so that the push motor is more efficient - the air that it's pushing has less resistance.  Loss of CFM isn't necessarily due to a fan's speed changing, it's because of the pressure created in the fan's path by resistance due to turbulence, etc.  Like you said, the standard induction motors used don't change speed as the speed is determined by the line frequency - but the amount of air they move per revolution varies depending on the pressure behind it.

[paulraphael]

On 9/1/2020 at 7:07 AM, weinoo said:

 

 

In an apartment, recirculating, so it does as much as a recirculating hood can do...

 

 

Did I understand correctly that codes in NYC don't allow you you to vent to the outside?

[paulraphael]

On 9/1/2020 at 7:42 AM, dcarch said:

Can a kitchen hood with 600 CFM to 900 CFM make not much noise?

 

The numbers might be optimistic, but there are many ways you could blow more air than a leaf blower and make less noise. A bigger motor is usually quieter than a smaller one. A bigger fan spinning more slowly is quieter than a small one spinning fast. 

 

There's also a question of the quality of the noise. People are less sensitive to low-frequency whooshing sounds than they are to high-frequency whining sounds.

 

Apple gives a master class in these principles with the their desktop workstations. By using large fans that spin more slowly, and by keeping air paths direct and open, they make air-cooled machines quiet enough to use in recording studios even when all the processor cores are going bonkers. 

[KennethT]

42 minutes ago, paulraphael said:

 

Did I understand correctly that codes in NYC don't allow you you to vent to the outside?

I don't know if it's a NYC code or if it varies by building.  I know my building allows it for some apartments (those with a window in the kitchen also have an exhaust in the plans - but I've only seen the plans, not the apt) but most apartments in the building (whose kitchen does not have access to a window wall) must have a recirculating fan with carbon filter.

[dcarch]

2 hours ago, KennethT said:

I don't know if it's a NYC code or if it varies by building.  I know my building allows it for some apartments (those with a window in the kitchen also have an exhaust in the plans - but I've only seen the plans, not the apt) but most apartments in the building (whose kitchen does not have access to a window wall) must have a recirculating fan with carbon filter.

 

Many areas' building codes require make-up air for kitchen exhaust, something like over 600 CFM.

 

dcarch

Edited September 2, 2020 by dcarch (log)

[dcarch]

2 hours ago, paulraphael said:

Apple gives a master class in these principles with the their desktop workstations. By using large fans that spin more slowly, and by keeping air paths direct and open, they make air-cooled machines quiet enough to use in recording studios even when all the processor cores are going bonkers. 

 

Typical desktop computer cooling fans give you about 50 to 100 CFM (12VDC) and run at about 1500 to 2000 RPM. Cooling fans for server room, data room equipment run much higher and noisier. I have many of those. TFC1212DE (120mm x 120mm) fan runs at 5000 RPM and 252 CFM. V80E128BHA5 (80mm x 80mm) fan runs at 6300 RPM and 73 CFM.

 

That's why I find it interesting that some kitchen exhaust fans claim they can quietly evacuate 600 to 900 CFM.

 

dcarch

[CentralMA]

This could work:

 

https://www.bigassfans.com

 

 

[Yiannos]

29 minutes ago, CentralMA said:

This could work:

 

https://www.bigassfans.com

 

 

 

Wow super super cool, all that stuff is amazing!