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The Use of Water in HVAC Systems

224 The HVAC World

reduced the energy consumption in the system. It must be remem-
bered that many existing systems were designed at a time when
energy was lower in cost and the use of these mechanical devices was
the most economical procedure at that time. The following discussion
will review the use of water in hot and chilled water systems. A simi-
lar evaluation will be made for condenser water in Chap. 11.

8.3 Hot and Chilled Water Systems
There are three zones of different activity in a hot or chilled water sys-
tem. The first zone is energy generation, the second zone is transporta-
tion of that energy, and the third zone is use of the energy (Fig. 8.4).
Zone 1: Energy generation. Energy for hot and chilled water systems is
generated in boilers and chillers. The efficiency of the boilers and
chillers may be affected appreciably by how the water is circulated
through them. The development of bypasses and special piping
arrangements has been achieved to enhance their efficiency.

Figure 8.4 Three zones of a chilled or hot water system.

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