Short answer
A convection oven cooks with dry heat circulated by a fan. A combi oven does that too, but can also add steam or cook with steam alone, so it can roast, steam, bake and braise in one cabinet while controlling moisture. Combis cost more and need a water supply and drain; a basic convection oven needs no water line or drain.
Convection ovens are the everyday choice for baking, roasting and reheating. They are built in half-size and full-size cavities, as countertop or floor models, single or double stacked.
A combi makes sense when one oven must do several jobs: steaming vegetables, roasting with humidity control to limit moisture loss, proofing, overnight cooking and rethermalizing. Most combis are programmable, which helps kitchens with less experienced staff produce consistent results.
Most combi manufacturers call for water treatment or filtration, because scale in the steam system is a common cause of service calls, and warranty terms can depend on water quality. Plan for a filter and a drain location when you lay out the space.
Updated · By Norpex