MC-TAIH62
图4显示了带有热水盘管的空气处理系统。类似的控制方案也适用于蒸汽盘管。如果选择蒸汽或热水来分配热能，可以使用高效锅炉来降低寿命周期成本。水通常比蒸汽更常用于将热能从锅炉传输到盘管或终端装置，因为水需要较少的安全措施，通常效率更高，尤其是在温和的气候条件下。恒温器热水供应阀排气风扇热水回流C2702图4。使用加热盘管的系统。空气处理系统通过将气流穿过包含加热介质的盘管、电加热盘管或熔炉来提供热量。单元加热器（图5）通常用于商店、储存区、楼梯间和码头。面板加热器（图6）通常用于加热地板，通常安装在楼板或地板结构中，但也可以安装在墙壁或天花板中。C2703单元加热器盘管风机蒸汽或热水供应冷凝水或热水回水疏水阀（如果蒸汽供应）图5。典型的单元加热器。C3035排气壁室外空气混合风门回风冷却盘管排水盘加热盘管风机图6。面板加热器。单元通风机（图7）用于教室，可包括加热和冷却盘管。对流加热器（图8）用于周边加热以及入口和走廊。红外加热器（图9）通常用于大面积（如飞机吊架、体育场）的局部加热。

Figure 4 shows an air handling system with a hot water coil. A similar control scheme would apply to a steam coil. If steam or hot water is chosen to distribute the heat energy, highefficiency boilers may be used to reduce life-cycle cost. Water generally is used more often than steam to transmit heat energy from the boiler to the coils or terminal units, because water requires fewer safety measures and is typically more efficient, especially in mild climates. THERMOSTAT HOT WATER SUPPLY VALVE DISCHARGE AIR FAN HOT WATER RETURN C2702 Fig. 4. System Using Heating Coil. An air handling system provides heat by moving an air stream across a coil containing a heating medium, across an electric heating coil, or through a furnace. Unit heaters (Fig. 5) are typically used in shops, storage areas, stairwells, and docks. Panel heaters (Fig. 6) are typically used for heating floors and are usually installed in a slab or floor structure, but may be installed in a wall or ceiling. C2703 UNIT HEATER COIL FAN STEAM OR HOT WATER SUPPLY CONDENSATE OR HOT WATER RETURN STEAM TRAP (IF STEAM SUPPLY) Fig. 5. Typical Unit Heater. C3035 DISCHARGE AIR WALL OUTDOOR AIR MIXING DAMPERS RETURN AIR COOLING COIL DRAIN PAN HEATING COIL FAN Fig. 6. Panel Heaters. Unit ventilators (Fig. 7) are used in classrooms and may include both a heating and a cooling coil. Convection heaters (Fig. 8) are used for perimeter heating and in entries and corridors. Infrared heaters (Fig. 9) are typically used for spot heating in large areas (e.g., aircraft hangers, stadiums).