Downdraft Systems

Proper kitchen ventilation is an important aspect of kitchen design. Cooking produces large amounts of smoke, steam, grease, odors, and heat that must be removed to clean the air and prevent damage to cabinets, walls, and other kitchen surfaces. Cooking on multiple burners at once, especially in conjunction with an oven or other heat source, may overtax a typical air conditioner without the aid of a ventilation system to remove excess heat above the stove.


Ventilation Systems and Health Risks

Improperly ventilated kitchens can also cause serious health problems. When fuel is burned at high temperatures, it produces nitrous oxides, which contribute to the development of ground-level ozone. Ground-level ozone is an aggravating factor in many respiratory problems. Proper ventilation in the kitchen is an important step to prevent or reduce such problems.

Updraft Ventilation Systems

There are two main types of kitchen ventilation system: updraft and downdraft. Updraft ventilation systems are located in range hoods and work by pulling polluted air up through a filter with the help of a fan and either venting it outside or cleaning and recirculating it. Because heated air rises, updraft hoods are the most effective type of kitchen ventilation system. However, updraft hoods are not always the most convenient type of ventilation system and when this is the case, downdraft systems provide an effective alternative.

Downdraft Ventilation Systems

Downdraft systems are built into base cabinets and work by pulling air down through vents on the back and sides of the cook-top with the aid of a fan and venting it to the outside. Downdraft systems work particularly well for island or peninsula cooktops where an overhead hood would be inconvenient or even dangerous, as well as small kitchens that simply lack the space for a proper overhead hood. Some people also prefer downdraft systems because they are less intrusive than overhead hoods to the kitchen's overall design. There are several types of downdraft system.

  • Flush-mount downdraft systems lie flush with the cooktop itself and are sometimes built into it. They have the disadvantage of sometimes disrupting the cooking process by pulling flames away from the cooking surface and are less efficient than overhead ranges or newer pop-up style downdraft systems.
  • Pop-up, or countertop level, downdrafts are retractable and lie flush with the countertop unless needed. These are more effective than flush-mount systems and less likely to interfere with cooking.

Downdraft vs. Updraft Ventilation Systems

Downdraft systems are generally not recommended for professional-level installations and are less effective than updraft systems at capturing steam and cooking vapors from taller pots and areas that are farther away from the fans. However, they are a great alternative when an overhead hood would not be practical.

For further information on kitchen ventilation see the following article from Ventilation Systems.