Range Hood FAQ - Common Installation Mistakes
Common Range Hood Installation Mistakes
One of the most important parts of a kitchen makeover is the range hood, the incredibly useful appliance that removes airborne contaminants created by the cooking process. Like other major appliances, a range hood needs to be installed, and, just like other major appliances, plenty of things could go wrong during the installation process.
Fortunately, these mistakes are easily avoidable. Here's a list of the most commonly made mistakes and the simple solutions.
#1 - Check Function
Checking the function of the range hood prior to installation seems like a common-sense thing, but in the flurry of activity surrounding a kitchen upgrade, it's easy to forget it. Many kitchen appliances, including most range hoods, are of the plug-in type, making it easy to grab a free outlet or extension cord and run through the basic functions of the unit.
#2 - Duct Size & Type
You should always follow the manufacturer's recommendations for the duct size and type when installing a range hood. Connecting a range hood to a smaller duct than specified will lead to loss of performance, and may even cause overheating problems leading to mechanical failure.
Almost all high-performance range hoods require the use of rigid ducting. The reason is simple: flexible ducting has ridged walls, which create turbulence. Instead of a smooth stream, the airflow is randomized, causing loss of performance and additional noise. Flexible ducting is also susceptible to cracking and rupture, which could cost hundreds of dollars to locate and repair.
#3 - Ductless / Recirculating Installation
Although it's always recommended to connect the range hood to an outside duct, there are situations where this is simply impossible. Many high-rise condominiums and co-operative buildings prohibit any modifications that pierce the outside walls of the building. Ultra-modern condos with concrete ceilings and floor-to-ceiling glass windows also exclude the possibility of an outside duct.
The solution is installing the range hood in "ductless", also called "recirculating" mode. In this situation, in addition to the metal filters that absorb the grease droplets, the hood uses charcoal filters (aka "carbon filters") to absorb odors, and finally the scrubbed air is released back into the room. Activated charcoal is a form of carbon that has been specially processed to increase its porousness and thus maximize its surface area.
#4 - Duct Discharge
One of the most serious mistakes in range hood installation is terminating the duct in an enclosed space, e. g. the attic. Not only will this cause the hood to operate improperly (if at all) due to the back-pressure, but channeling the warm moist air from the kitchen into attic space will cause a serious problem with mold growth.
#5 - Duct Termination
An outside duct that exits through a side wall should end with a duct cap, while roof-mounted ducts are sometimes terminated with a "U" shaped elbow, allowing the air to exit while keeping out the rain and snow. Make sure the cap is the same size/diameter as the duct - using a smaller cap will cause problems with airflow and static pressure.
Regardless of the type of termination, it's important to have a damper (also called "backdraft" or "airflow controller") at the end of the duct. The damper keeps outside air from back-flowing into the duct, as well as keeping out unpleasant surprises in the form of birds, insects, and squirrels.
#6 - Electrical Connection
One of the most common problems with appliance installation is the electrical connection. The rule-of-thumb is simple: if an appliance comes with exposed wires, it must be hardwired; if it comes with a plug, it must be plugged in. Following this rule will avoid problems with manufacturer's warranty, as well as potential issues with inspection. Many high-end range hoods are supplied with a cord-and-plug assembly, and must be connected to a properly grounded outlet.
#7 - Electrical Line
Another good rule to follow is connecting each major appliance - including the range hood - to its own separate (dedicated) electrical line. It's not a question of amperage (or "load") on each wire, but rather ensuring that each appliance does not interfere with the others by causing voltage drops or introducing electrical noise into the line. Sensitive electronics found in many modern appliances will last a lot longer when the power supply is stable, and troubleshooting and maintenance is a lot simpler when each circuit can be isolated.
#8 - Installation Height
There are several factors that affect how high a range hood should be installed above the cooking surface. First and foremost, check out the range hood manufacturer's recommendations. Typical range hoods are installed in the 26-to-30 inch range above the cooktop, although this may vary from a low of 18 to a high of 36 inches.
Since the air polluted from cooking doesn't rise in a perfectly straight line, but spreads out rather aggressively, it's a good idea to position the range hood low enough to give it a good chance to capture the smoke/steam. Also, it's recommended to position the range hood at a height where the lights will be below eye level, which also keeps the control panel within easy reach and makes cleaning easier.
#9 - Proper Support
One of the most dangerous problems with range hood installation is attaching the unit to sheet-rock alone. Regardless of the weight, any range hood should be attached to structural beams or joists, in order to provide proper long-term support. If there is no beam/joist at the intended range hood location, a cross-brace made from 2x4's, ¾-inch plywood, or other strong material, is an acceptable substitute.
#10 - Protective Film
In order to avoid scratches during installation, the duct covers (vertical chimneys) on many high-end range hoods are covered (fully or partially) with a protective plastic film. When you first unpack the range hood, you may be surprised that instead of stainless steel, some parts look like they're painted white. Make sure the installer is aware that this film is intended to remain in place for the duration of the install, as the inevitable adjustments are made. Once the installation is finished, the film may be carefully removed.