where does the heat come from when broiling
Charbroiler A charbroiler (also referred to as a chargrill, char-broiler or simply broiler) is a commonly used cooking device consisting of a series of grates or ribs that can be heated using a variety of means, and is used in both residential and commercial applications for a variety of cooking operations. The heat source is almost always beneath the cooking surface â€“ for gas-fired applications this is referred to as an under-fired broiler. Most commonly the charbroiler is a series of long evenly spaced metal ribs over a large combustion chamber filled with an array of burners that may have a deflector, briquettes or radiant between the burner and the cooking surface.
Hydronics These systems depend on the proper operation of thermostatic air-venting valves located on radiators throughout the heated area. When the system is not in use, these valves are open to the atmosphere, and radiators and pipes contain air. When a heating cycle begins, the boiler produces steam, which expands and displaces the air in the system. The air exits the system through the air-venting valves on the radiators and on the steam pipes themselves. The thermostatic valves close when they become hot; in the most common kind, the vapor pressure of a small amount of alcohol in the valve exerts the force to actuate the valve and prevent steam from leaving the radiator. When the valve cools, air enters the system to replace the condensing steam.