What appliances are NOT required to be vented?

Counter appliances are not required to be vented because they typically do not produce harmful combustion gases like gas appliances. These appliances, such as toasters, microwave ovens, and electric griddles, generally use electric power and therefore do not create emissions that necessitate venting to the outside. They are designed for safe indoor use without the need for an exhaust system.

In contrast, appliances like gas water heaters and industrial furnaces generate combustion gases that need to be safely vented to prevent the accumulation of harmful substances in the living or working environment. Electric ovens, while also not emitting combustion gases, are included in a different context of appliance types mainly requiring venting for proper kitchen ventilation and odor management, rather than safety concerns about harmful emissions. Therefore, counter appliances stand out as the category that can operate effectively without additional venting requirements.