Page 10 - HVAC Pump Handbook

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Digital Electronics and HVAC Pumps

Digital Electronics and HVAC Pumps 7

Figure 1.1 Energy and hydraulic gradients. (From Karassik et al., Pump Handbook,
3rd ed, McGraw-Hill, used with permission.)

such as an open cooling tower circuit; the closed systems of HAVC in-
cluding chilled and hot water systems consist of a loop, since the
water returns to its source. The individual losses in a water system
are explained in this diagram. Velocity head cannot be ignored, since
it represents the kinetic energy of the water in the pipe. Velocity head
will be emphasized in this book when it becomes a factor in pipe de-
sign, particularly in piping around chillers and in the calculation of
pipe fitting and valve losses.

1.4 Speed and Accuracy of Electronic
Design of Water Systems
The tremendous amount of time saved by electronic design enables the
engineer to evaluate a water system under a number of different de-
sign constraints. The designer can load certain design requirements
into a computer, and while the computer is doing all the detailed calcu-
lations for that program, the next program of design considerations

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