Frequently Asked Questions: Range Hoods
What's the best way to clean the
surface of my hood?
Stainless steel hoods should be washed regularly with a clean cloth,
warm water and mild soap or dish detergent. Clean in the direction of
the polish lines. Rinse well with clear water and wipe dry immediately.
You may wish to apply light oil used for furniture polishing to emphasize
it's bright finish.
Wiping regularly with mild soap/detergent and warm water should protect
painted hood surfaces. Be cautious about using "New and Improved"
cleaning agents. Your hood is installed over hot cooking equipment. Most
chemicals found in cleaning agents react with heat to loosen paint.
How often should I clean my filters?
The aluminum mesh grease filters should be washed in your dishwasher
approximately every month depending on the amount of usage. Wash often
if your cooking style generates greater grease like frying foods or wok
cooking. You cannot clean the non-duct carbon filters; they must be replaced.
Baffle filters, which are used in professional style range hoods products,
are designed to operate longer in high grease conditions without loss
of performance. Generally, these need to be cleaned with soap and water
whenever the surfaces become unsightly.
How often should the non-ducted
range hood filters be replaced?
It depends on the frequency and type of cooking that is performed. Normally,
every three (3) to six (6) months is recommended for replacing the charcoal
filters. Some charcoal filters are designed with an indicator mechanism
that will change color as a signal to replace the filter.
Can I replace an Over The Range
Microwave with a Range Hood?
Yes. Whether your current OTR is duct-free or ducted, we offer a complete
line of range hoods to effectively ventilate your cooking area.
Which is better, ducted or ductless?
Range hoods should be ducted to the outside of the home. While duct-free
filters trap some of the grease and odors from normal cooking, the humidity,
smoke and heat will all be recirculated back into the home. If the duct-free
filters are not regularly replaced, eventually the grease and odor catching
effect will no longer protect your home from impurities.
High BTU gas cooking equipment should always be ducted to the outside
of the home. If this is impossible, high performance convertible hoods
and filters are available in some models. Contact the Technical Support
What type of duct is best for venting
a range hood?
Range hoods must be vented using metal duct. Given a choice between flexible
metal duct and smooth metal duct, go with the smooth. The ridges found
in flexible metal duct create turbulence and will diminish airflow.
- NEVER use 4" dryer duct or any plastic duct on a range hood installation.
The minimum size duct allowed on most range hoods is 3 ¼"
by 10" which is equivalent to 6" round. More powerful hoods
require even larger duct sizes up to 10" round. Consult the specifications
for the model you have chosen.
- When remodeling and changing hood and cooking equipment types, do
not reduce the ductwork size to less than the size specified for the
range hood. Decreasing the duct size restricts the performance of the
range hood ventilator.
What do the CFM and Sone ratings
CFM stands for Cubic Feet per Minute of exhausting air flow. The higher
the number, the greater the amount of air that is exhausted using the
A Sone is an internationally recognized unit of loudness. Sones are a
linear measure like inches. Doubling the sone value is equivalent to doubling
the loudness. To get a sense of what one sone represents, one Sone is
equivalent to the sound of a quiet refrigerator in a quiet kitchen. Typically,
the Sone level is measured at maximum CFM (speed), however, some newer
products are also being tested at normal CFM (speed) settings to provide
consumers with typical sound level information.
All Broan-NuTone CFM and Sone ratings are HVI certivied so you can rely
What is "normal" setting considered to be?
The low setting is considered to be normal.
How much CFM do I need for my Range
or Cook Top?
For conventional electric and gas ranges or cook tops, we offer a complete
line of hoods that can fit your cooking needs with features you desire.
For high output gas ranges or cook tops, the minimum rate of 1 CFM of
ventilation per 100 BTU is recommended.
What is the CFM and sone rating
on a non-duct range hood?
There is no national standard for the measurement of CFM or Sones on
a non-ducted hood because the air is not exhausted, it is re-circulated.
How are range hoods ducted?
There are several ducting methods, depending on the model. The 3 ¼"
X 10" duct may vent from the top vertically or horizontally through
the rear of the product. The 7" round duct vents through the top
of the range hood. Some hoods are single use ducted and some are convertible,
meaning that the hood is designed to be installed using more than one
duct method or direction.
What does the term "convertible"
The term "convertible" refers to a hood that can be installed
in different ducting modes. Typically a "convertible hood" can
accommodate: 7" round ducted, 3 ¼" X 10" vertical
or horizontal ducted , and non-ducted applications available at installation.
How far can I run my ductwork to
exhaust my hood?
For maximum performance keep the duct straight and short. Use the shortest
route with the fewest turns possible. 45° turns are better than 90°
turns. Be sure to use an external roof or wall cap. If in doubt, consult
a qualified designer/installer knowledgeable in ventilation or contact
the Technical Support Group.
Can I exhaust my hood into my attic
instead of out the roof or wall?
No. You should never exhaust air into spaces within walls, ceilings,
attics, crawl spaces or garages. The humidity and grease collect in the
Can I install an external vent fan
or in-line fan to boost the performance of my hood ventilation equipment?
Do not install in-line or external fans to boost a hood that has it's
own power unit. In general, attempting that type of "boost"
will not be effective. Also, most cooking ventilation products are designed
with fan switches matched to the original motor amp ratings and would
not support the increased amp draw from additional motor installations.
This type of tampering voids the original manufacturer's warranty. If
you want a remote/extended fan, there are hood products made for that
type of installation.
How high should I mount my hood
above my stove?
Most common installations require a range of 18" - 24" between
the bottom of the hood and the top of the cook top. This will provide
the best capture area for cooking impurities.
For high capacity ventilators, the distance from the cooking surface
to the bottom of the hood should be 22" - 30" unless otherwise
noted for a specific hood or range.
Is a cabinet above the hood required
to mount the product?
Some hood models are designed for mounting to the wall and do not require
cabinet for mounting. Hoods designed for undercabinet applications need
a cabinet or soffit above it, or a Model 35 wall mount kit.
My ceiling height is much taller
than most kitchens and I want my stove on an island. What do I do about
- Broan -NuTone has LoSone Select ventilators available that are approved
for kitchen applications.
- Drop-in cooking equipment can be vented with one of Broan-NuTone's
- Custom chimney extensions are available for Island hoods for up to
10' ceilings. Contact Technical Support Group if your ceiling is higher
- Contact your local Retailer/Distributor or call the Technical Support
May I remove the hood controls and
mount them remote from the hood?
Altering the product voids manufacturer's warranty. Check for models
that already offer remote switch options.
If I have a custom hood built for
my kitchen, does Broan provide protective liner for their hood inserts?
No. You would need to find a metal fabricator in your area to design
a liner for your hood, especially if local building codes require one.
Broan does sell a complete custom kit that includes an integrated liner
in specific sizes and 30"-42" widths. See Model 103023.
Does Broan-Nutone build custom design
While we do not build custom hoods, Broan provides a number of blower
inserts designed to accommodate the ventilation needs of most cooking
equipment. See our Specialty Hood Section.
Does a cord come with a hood?
We provide electrical connections for hard-wiring the product through a wall; however, in Canada, cord kits are not provided, nor are they available.
May I use a downdraft with a slide-in
There is no way to use downdrafts with stoves or built-in ovens. The
units must only be installed with drop-in cooking equipment.
What power units are available for
custom range hoods?
Currently, there are two power modules offered by Broan and NuTone. The
PM25 (250 cfm) and the PM44 (440 cfm). Both units come in either black
or white. Broan also offers a custom hood kit complete with liner, see
Is the hood width the actual measure
that is advertised?
No. They are between an 1/8" & 1/4" smaller than listed
so that they fit properly into an opening of that nominal size.