It depends on how you cook, but for high volume cooking, you should...
A downdraft range has an integral vent, so it pulls the heat, steam, odor and grease through the range into the duct and to the outside.
Back in the 1980’s, GE, Roper, Modern Maid, Thermador and Jenn-Air all marketed a downdraft range. Downdrafts were popular, because it allowed you to place a range in an island or in the middle of the kitchen without requiring an overhead vent.
The average kitchen accumulates 4 gallons of grease per year, so it's incredibly important to have good ventilation.
Proper ventilation clears the air of smoke and odors and prevents particles from accumulating on ledges, curtains and cabinets.
I am not a huge fan of downdrafts. If you are buying a gas range, the BTU’s of a new gas range will be at least 30% more powerful than a gas range 10 years ago.
There will be at least one burner with 15,000 BTU's or hotter, which means you need to properly vent your kitchen.
The downdraft is Jenn-Airs signature product. The vent is in the middle of the cooktop or stove and vented down through the product and out of your house.
That’s the theory, but I never saw it in operation until last Sunday.
Placing your cooking appliances is the toughest part of planning a kitchen. Every other appliance is pretty easy.
Cooking with various sizes, wall ovens, cooktops and stoves has the most variables. Downdrafts are not as popular as they were in the 1980s, but still can solve some problems in kitchen islands or replacing other downdrafts.
At one time, Modern Maid, GE, Roper, Amana and Jenn-Air all produced a downdraft range. Now Jenn-Air is the only manufacturer left manufacturing this product.