Everything You Need to Know About Ventilation

by Tom Papageorge


One of the things that people commonly forget to think about is kitchen ventilation. Smoke, grease, heat, water, food, and odors are by-products of cooking that escape into the air while using a stovetop, accumulating on your kitchen's and home's surfaces and giving the room a grubby, uncomfortable layer. The primary purpose of kitchen ventilation is to reduce these by-products by lessening smells, minimizing condensation and humidity, and controlling unwanted heat by extracting them to the exterior of the home. A range hood, or a fan placed above the stovetop, is also able to trap cooking grease and keep it from splashing all over your kitchen and upholstered furniture nearby.

There are also health concerns. When these harmful pollutants are released into the air, ultra-fine particles coated in all sorts of chemicals are absorbed into your body. When you're cooking without a ventilation system, you breathe in nitrogen dioxide. When nitrogen dioxide is concentrated, it has been shown to cause asthma and irritation in the lungs.

To keep your kitchen and body comfortable and clean, here's what you need to know before making the right decision about a kitchen ventilation system for your home.

Different Stovetop, Different Ventilation

There are 3 types of ventilation systems: a ventilation hood, a range hood, and an exhaust fan.

Ventilation efficiency is measured by how many cubic feet of air the system removes per minute, or CFM. This number should match a stove’s energy output. Thus, a gas stove that releases10,000 BTU's of total burner output would need a range hood that can accommodate 100 cubic feet per minute.

The suggested CFM requirements for cooktops:

  • “Regular” gas cooktops output 40,000 BTU's. To calculate your gas stove's BTU, add the power of each burner and divide the total by 100. So a “regular” gas system would need a 300 CFM fan.
  • Electric stoves are low-powered and should need a ventilation output between 150 and 300 CFM. (Electric deep fryers should be treated as a gas stovetop.
  • “Professional” stovetops can generate tremendous amounts of heat depending on the setting. If they are in a restaurant, they will obviously need a ventilation system with a higher CFM. You can calculate the CFM of a professional, or high output stove by dividing the BTU's by 100. You should consider a higher CFM with professional stovetops if you have an extra long ducting system, the range hood is positioned high above, you cannot provide the structural area in width and depth greater than the range top, or if you want to keep noise levels at a lower volume.

Depending on the ventilation system's distance to the outside, the type and number of bends, and the wall plate and damper's resistance, the output can be considerably reduced. When choosing a ventilation system, understand the output and type of range top you're working with, the size and positioning of the hood, and the length and design of your home's ductwork. In addition, you should lean toward a stronger vent if you frequently cook Asian or stir-fry.



Ventilation Set-Ups

An updraft system contains a range hood that hangs above the stovetop. It sucks harmful by-products outside or recirculates them under the hood (if ductless). These systems are cost-effective because naturally, hot air rises. Newer models of updraft systems, too, are not equipped with an ugly, boxy metal hood. Instead they offer sleek designs with flat or lightly curved glass or metal panes that can be tucked away when not in use.

A downdraft system pulls air downward or to the back to the cooktop through built-in vents. Unlike hoods, downdraft designs are often integrated into the cooking appliance. These systems are best for island set-ups or for kitchens with cathedral ceilings so that the cook is not in the way of the ventilator.

Ductless, or recirculating range hoods, filter some pollutants, but not all. Many are unknowingly released back into the room. If installing a ductless system, be sure that it is ducted outside. However, many professionals do not believe ductless systems are true ventilators. These systems are also not recommended for gas stoves due to a release of carbon monoxide.

Ducted range hoods operate on fans, or blowers. The fans twist air and cooking by-products up through the exhaust duct. The air, however, is drug along the sides of the duct, reducing the exhaust output. When looking for a ducted system, look for efficient blowers that do not cause much turbulence to lessen the air drag inside the duct.



Stovetop Ventilation Designs

Dependent on your stovetop and price limitations, there are a myriad of stovetop ventilation designs available. Budget-minded updraft units can be priced as low as $200. Downdraft units typically run between $500 and $700. For a selection of up- and downdraft units that output 500 CFM or more, you're likely to spend between $600 and $1,200. And if design is your primary concern, be ready to exceed $1,200 to $2,000.

There are many types of range hoods designs not limited to: under the cabinet mounts, wall mounts, ceiling (island) mounts, downdraft ventilation, ventilator power packs, and wall ventilation fans. Design options are addressable for all ventilation systems, too, allowing you the choices of: color, stainless steel or other metal finishes, and between fans, packs, motors, and other interior workings.



Whatever model you choose, make sure to turn it on as soon as you begin cooking. Also, ventilation systems need to be cleaned once every 3 months. Some even conveniently slide out and fit on the top rack of a dishwasher.