1. All Water System & Air-Water
System

2. In an All - Water System
water (the controllable
fluid) is circulated to the
space. Thus a special type of
terminal unit (Figure below)
is required in the space.
Essentially each space
requires a small air handling
unit consisting of a coil, a
fan, and a filter.

4. Return air (Figure 26) is
drawn into the unit by the
suction of the fan. The air
is then filtered and passes
on to the suction of the fan.
From this point the same thing happens
what has happened in the All Air.
So what has happened in All Air at this stage.

7. Heat removed from the space
(Figure above) is then
transferred to the
refrigeration equipment thru
a network of chilled water
pipes. Heat rejection
equipment then transfers the
heat from the refrigeration
equipment to the outdoors.

9. The only thing lacking is
proper odor removal, because
an All - Water System
circulates water, not air.

10. Air - Water System
The lack of odor removal
leads us to the third basic
system - the Air-Water
System.
A separate air system
(Figure below) is provided to
supply fresh ventilation air
to the space.