Fan-coil units and unit ventilators are directly controlled
by local thermostats, often located within the
unit, making this system one of the most energy efficient.
Drawbacks to their use is a lack of humidity control
and the fact that all maintenance must occur within
the occupied space.
Fan-coil units are typically used in buildings which
have many zones located primarily along exterior walls,
such as schools, hotels, apartments and office buildings.
They are also an excellent choice for retrofitting air-conditioning
into buildings with low floor-to-floor heights.
Although a four-pipe fan-coil system can be used for a
thermally massive building with high internal loads, it
suffers the drawback that the cooling of interior zones in