ABSTRACT
The hot water for domestic purposes in a small building is usually heated by the kitchen fire. In large buildings, where considerable quantities of water are required, a separate boiler is used for heating the water. Heated bodies transmit heat by radiation, by convection, and by conduction. Radiant heat passes from one body to another without affecting the intervening atmosphere. The radiation and convection methods of heating are respectively termed the direct and indirect methods of conveying heat from one place. Convection currents will be set up in the air in a room by the presence of people in the room, or by a heating medium, such as a stove or a gas burner situated in the room. The Hypocaust method of warming consists in passing air through tubes surrounded by a fire. The heated air is conveyed through ducts to the lower part of the room to be heated.
