It may seem obvious, but the “Why do I need a range hood?” question pops up far more frequently than I ever thought it would. It is important to know a few facts and figures pertaining to kitchen ventilation and range hoods when you are beginning your quest for appliances.
The primary purposes of kitchen ventilation are to reduce cooking smells, toxic
(Natural or Propane) gas, heat, and condensation by exhausting those things
outside. Another important purpose of a range hood is to trap grease to prevent it from being deposited all over your kitchen. Nobody likes a sticky, stinky kitchen! There are 5 major types of kitchen ventilation and each one geared towards a different installation scenario; aesthetic preference, power level, and noise factor.
Under Cabinet Mounted
Just as the title says, this type of range hood is fixed to the bottom of a cabinet. A good example of this is the which I have pictured here. Vent-A-Hood PRH9230SS, It may duct directly out the back, may go up through the cabinet or, may go up a little and then out the back. You may lose some storage in that cabinet above your range, but so what? It’s always messy above the hood and it is never easy to grab that bottle of cumin that wedged itself to the back corner anyway! Very few of this type of range hood have a remote blower.
A remote blower is basically the motor and fan of the ventilation system that sits further back in the ducting away from the hood itself. A remote blow will generally reduce some noise from your ventilation system.
This type of mount may also include a microwave for additional convenience. A prime example of that is the LG 30” LMHM2237BD which comes in the super popular black stainless steel. Definitely worth a click to see that one. You’ll notice that this model has a unique pull-out canopy feature which enhances performance (it sucks more!)
This type of vent hood is directly affixed to the wall and may have a decorative chimney or soffit, to line up with the top of your cabinets or to “disappear” into your ceiling. It may be ducted straight out from the back of the hood, be ducted straight up from the hood and out a vent in your roof, or up and then horizontally out through a vent in the side of the exterior of your home. These hoods come is many different shapes, colors, finishes and designs. You will see most of these in stainless steel, much like the one that I have pictured below. This is the Elica LEONE ELG630SS, such an iconic style and so easy to clean.
This type of range hood hangs from the ceiling over an island or peninsula. It may also hang from peninsula wall cabinets. You may choose to hang it higher to avoid blocking a view and, if so, it will need more coverage than it would in a wall mount situation. I would recommend at least an additional 3″ all round (30″ stove would require a 36″ hood. It will also need more CFM to compensate for the extra height and for breezes passing through your kitchen. This type of hood is generally going to be over-the-top styled as they are seen as a showpiece of the kitchen. The island hood that I have shown below is the Best IC35190B and as you can see it is very styled, in glossy black and stainless steel.
Venting downwards has come a long way in the last 20 years and is mostly used in kitchen island or peninsula situations. This type of unit can also be used for a cooktop near a wall. The fumes are drawn downward under the floor and vented out (like what is frequently done to vent a clothes dryer.
Downdraft units are relatively inefficient because they have to fight the natural upward flow of air and are most often used in an island situation if you don’t want to block a view or if your range top needs to be placed in front of a window.
If you were just looking to ventilate a cooktop, you could install a standalone downdraft which can be relatively plain like Zephyr’s DD1E30AS downdraft or incredibly exotic like the elegantly styled Cattura Downdraft Ventilator by Best Range Hoods.
If you were looking to downdraft a range, you would need to purchase an “all-in-one” unit where the downdraft is built-into the range itself. JennAir’s JDS1740FP or KitchenAid’s KSED950ESS, pictured below, are excellent all-in-one downdraft ranges.
Power Packs (sometimes referred to as insert or liner hoods)
These power packs contain the “guts” of a custom or made-to-order range hood and contain the blower(s), grease trap(s), lights and (usually) controls. They are intended mainly for use in custom or wood hoods or “your own” style hood. They fit into your own creation or into a shell of wood, plaster or metal manufactured by others.
Power Packs often come with an easy-to-clean, powder coat metal or stainless steel liner to ensure a snug and easy-to-clean bottom for your hood. Now, these will not be pretty, but I did want to illustrate what the insert is going to look like. The one I have chosen is the Vent-A-Hood BH234SLDSS which is shown above. All Vent-A-Hood liners come complete with blowers, lights, switches and canopy. They are easily installed into your custom hood!
“How Much Power is enough for My Ventilation?”
Here’s the technical “deep dive” that you’ll want to be armed with when determining what kind of ventilation is perfect for your needs.
Cubic Feet per Minute (CFM) is a measure of the volume of air being exhausted through your range hood. This number is how much your vent hood sucks. This measurement is always based on when the hood is running at full speed. Depending on its distance to the outside, the diameter of the ductwork, type and number of bends, and the type of cap on your home at the end of the duct run, this output may be considerably reduced.
The CFM requirement for your hood will depend on
- the type (gas or electric) and cooktop output (standard heat or flame throwing PRO caliber burners),
- the size of the hood canopy,
- the height of the hood,
- and the length and configuration of your ductwork.
I can say with confidence that it is better to have too much power and not need it than not enough power when you’re burning dinner!
Generally speaking an electric cook top is low powered and should only need a range hood output between 150cfm – 300cfm. If you have an electric deep fat fryer you will need to treat it as if it was a gas stove top.
“Regular” gas cook tops have outputs of up to around 40,000 British Thermal Units (BTU) and, since they are almost always used in an “against the wall” situation, you can use this simple formula to help make your choice. Calculate your cook top’s BTU rating by adding the power of each burner and then divide the total by 100, e.g. a 30,000btu top will require a 300cfm fan.
High Output [“Professional”]:
Professional style gas range tops can reach outputs akin to a small stove in a restaurant and they can generate enormous amounts of heat. The simple calculation of Total BTUs/100 = CFM (e.g. a 60,000 BTU top will need 600cfm blower) is fine in many situations, but you may need to consider more CFM if one or more of these factors apply:
- You have an extra-long run of ducting (especially with 90 degree bends)
- The range hood is positioned extra high over the range top
- Your hood canopy cannot be wider than the cooking surface
- You want to keep the noise level down, simply choose an extra powerful hood but run it at a lower setting.
While my customers obviously want an efficient smoke free kitchen, one major concern often expressed to me is the noise level – and I am fairly sure it will be a big concern for you too. All too frequently, I hear from customers that the hood isn’t important to them because they rarely if ever plan to turn it on.
Most of the noise from a range hood comes from the blower motor but a considerable level also comes from the rush of air through the grease filters and ducting. Noise can be much more pronounced if any of the following conditions exist:
- the ducting is incorrectly sized (example, when using a 6″ diameter duct for a hood that requires 8″)
- the ducting has too many 90 degree bends between the hood and the outside of the home
- the cap at the end of the duct run isn’t appropriate for the diameter or amount of wind being moved
Obviously quieter is better, but make sure your hood has sufficient power for the job. A great work around is to buy a higher output hood than you need and run it at lower speed. This will reduce the noise a lot. Just make sure it has a variable speed control or multispeed even if it is more costly. Consider the extra cost against the number of years of aggravation saved!
Kitchen ventilation can be an expensive, complicated, and frustrating portion of any kitchen design. With time, patience, some great advice and planning, it can be pretty easy to figure out what you need. I strongly recommend consulting an appliance professional that is well versed in the ins and outs of kitchen vents…… Like the ones at Metropolitan Appliance (**shameless plug**)!