Range Hoods – How to choose an exhaust system

Purchasing a range hood can be a costly and confusing business. Not only do you have so many designs to choose from, but what power of fan do you need? What kind of filters? What’s the difference between the metals used, or whether it’s a commercial unit or custom made?

Fan/ blower

Power: CFM

Blowers are rated by CFM – that is, how much air they move, and the requirement is based on the stove top you have. The more heat produced the bigger the blower you need. Check with the manufacturer of your stove for their recommendations as well as your local code requirements. A general guide is: for every 10,000 BTUs your cooktop produces, you need 100 CFM. For example, a cooktop producing 90,000 BTUs would need a 900 CFM unit.

You should purchase an adequate size, but don’t go overboard. If you choose a fan much larger than you need, you could end up ventilating your whole house!

Internal or external fan

An internal unit is positioned inside the range hood and pushes the air outside through the duct. An external unit sits outside of the house, on an exterior wall or roof and draws the air out. These are useful for larger fans where noise can become an issue. Note: often external units will require 10” duct and so you must also check if that is a feasible option with the structure of your home.

Safety features

Consider purchasing a unit with built in heat sensors. These will turn the fan on should excessive heat be detected and draw the heat out of the kitchen. Make sure you also chose a unit that is UL listed and HVI certified.

Filters

Different companies have different options – from regular mesh filters, baffle filters and stainless steel trays that trap grease. Modern units have filters that are dishwasher safe. Baffle filters give a professional restaurant style look but can be more expensive. What you chose is usually a personal preference on style rather than function.

Above: Standard mesh filters by Broan

Metals & construction

By far the most common metal used to range hoods is stainless steel. Increasingly popular are range hoods painted to match your appliances, zinc metal and especially copper, a more expensive metal but highly sought after by homeowners who want something different and more dramatic in their homes.

Custom copper combined with
stainless trim

Custom painted
to match appliances

Copper also comes in different thicknesses, often measured in gauge or weight. The lower the gauge number, the heavier and thicker the copper. Roofers, for example, commonly use 16oz or 20oz copper (technically called “soft copper”). For our range hoods, we only ever use 48oz copper – much heavier duty & creating a much stronger hood that is far less likely to dent or ding with every day use as well as being less susceptible to surrounding heat.

With heavy duty copper comes a heavy range hood and so requires a sturdy internal structure and welded seams. Welding copper is a highly skilled and labor intensive job, far more so than welding harder metals such as steel. It provides a completely seamless and much stronger range hood. Although thicker copper is much harder to work with, the final result is most definitely worth it in looks, quality & durability! Your hood should be built to last decades.

Commercial or custom made

Commercial hoods may vary from $30 to thousands of dollars and as with most things, what you pay is usually what you get. Low CFM fans and cheaper construction accompany the lower priced units. If you need a big fan for a big range or want a specialty item, be prepared for a higher sticker price.

Clients choose custom & bespoke pieces for a variety of reasons: special requirements, made in USA, handmade versus machine made, or simply because they want to go back to traditional craftsmanship & embrace true quality craftsmanship at its finest. And for us, custom made is more personal - it's made for you.

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