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Repair/replacement for a range hood fan


MRTkH's Avatar
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Join Date: Aug 2013
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UT

03-19-17, 10:28 PM   #1 (permalink)  
Repair/replacement for a range hood fan

Folks:

Photos below should help in the explanation.

Our range hood that vents straight up to the roof really is failing in its ability to evacuate cooking smells, gases, etc. To be honest, it isn't just NOW, it's always not been very effective in this regard--worse, we cook a LOT at home and we battle to not smell like cooked onions all the time.

I honestly don't know if its because of its age (tired motor) or if it was always under powered for what we like to cook.

Couple of facts first:

#1) It is 17 years old. I've replaced the metallic grease filters on it. So they are not impeding flow. The fan blades do appear to have grease on them; I've not tried to fix them yet as I think it might just be under powered to begin with.

#2) Even when we bought the home and moved in (when it was only 4 years old) it would work "ok" but if you had 2 burners going,, it couldn't keep up.

#3) Its dimensions that are visible are 22 inches wide by 11 deep and 6 1/2 inches down (or hanging into the room). Photos will help folks see how it fits.

#4) Brand and model: Rangaire model 221.

#5) Label says CFM Vert 440. Sones Vert 5.5.

I don't know HOW its pulling 440 CFM as that would cause a solid draft if it indeed was pulling that much. I just lit a paper towel on fire under it and the flame would move a little, but not much.

#6) When you turn it on full speed and let it run then turn it off, when it is almost stopped you can hear the back flow flapper close. So that's at least moving.

My questions are:

Is 440 CFM vertical typical for a 4 burner range?

Are there stronger out there that may fit in this type of area? I don't want to take down the exterior hood, just replace the inside with a stronger unit.

What do folks typically use in terms of CFM for a 4 ranger burner? Again, I would like to evacuate most of the cooking odors--if at all possible.

Like to know were to shop for such a device as I only need the fan and light unit and not a full hood.

Thx in advance!


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PJmax's Avatar
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03-19-17, 10:48 PM   #2 (permalink)  
You need a very powerful unit moving a lot of air and also very noisy to do what you want.

You have a damper in the blower unit and you can hear it work. There should be another one in the roof vent and it may be stuck.

You said fan blades..... does it use an actual fan blade or squirrel cage wheels ?

I've installed those units for customers but they were always supplied to me by either the customer or the kitchen contractor. I don't know if the inside unit can be replaced by itself.
I'm sure it can with an original but I'm not sure about a replacement from a different company.

The model # 221 is only a partial model number.


~ Pete ~

 
Pilot Dane's Avatar
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03-20-17, 06:54 AM   #3 (permalink)  
The cfm rating of the vent hood is in free air with no exhaust duct and no sealed house on the other end. Install that hood with 10' of exhaust duct in a modern, well sealed home and the volume it moves drops considerably. Things like a under sized or long exhaust duct or bends in the exhaust run reduce it's performance as does a well sealed home since when the fan runs it creates a vacuum in the home which it must fight.

As a quick test you can try opening a door or window when running the exhaust fan to see if that helps improve the flow. You can also peek up into the attic and see what sort of exhaust ducting you have. Maybe the installers did something stupid like use under sized duct or a smaller than required vent through the roof.

There are higher volume exhaust hoods available. In most cases it requires replacing your entire hood. I don't know of easy to install upgrade kits to switch out the factory blower assembly for another, more powerful one. It can't hurt to check with the manufacturer though to see if they do have a more powerful blower that will work. After that, in the extreme, you could consider removing the fan assembly from your hood and go with a roof mounted, commercial style exhaust blower.

 
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