Farberware T4850 convection oven, $20.

Two of the most common convection ovens you're likely to encounter are the Farberware 460 and the Farberware T4850. Most people who see these ovens tend to think of them as oversized toaster ovens. But despite their unassuming, boxy looks, these ovens are costly new which means that people really go after them used on eBay. Now... what's the difference between convection cooking and a regular oven?

As opposed to a normal oven, which simply heats up the air inside the oven, a convection oven uses a fan to blow the hot air around inside the oven. Convection cooking allows food to cook in up to half the time, and at lower temperatures. How can that be? As food is heated in an oven, an insulation barrier forms on the surface of the food, caused by the exchange of heat between the hot air and the cold food, and by the evaporation of moisture in the food. This insulation greatly slows the cooking process. A convection oven literally blows away this insulation layer of air and replaces it with fresh hot air, making the heat transfer faster and more efficient.

To illustrate an example of the convection process that we're all familiar with, just think of "wind chill." A crisp, calm 65-degree spring day may be comfortable shirt sleeve weather, but throw in a stiff breeze, and all of a sudden you're freezing. The temperatures have been flipped in this example, but it's the same principle in action. It all has to do with the transfer of heat between an object and the medium around it, which in this case is air.

As you can see, we're constantly straddling the line between "too much info" and helping you see who wants what and why they want it. After all, why would these ovens sell for $100 to $200 on eBay if they were nothing more than big toaster ovens?

Although the model 460 is an earlier model than the T4850, both of them still bring in good money on eBay. The 460 was common in both silver and woodgrain finish, but all of the T4850's I've seen have been white. This oven sold on eBay for $106.

Photo of the Farberware T-4850 convection oven