Page 110 - HVAC Pump Handbook

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Source: HVAC Pump Handbook

Chapter
5

Physical Description of

HVAC Pumps

5.1 Introduction
A number of different types of centrifugal pumps are used to handle
all the various pump applications in the HVAC industry. HVAC
pumps can vary from small in-line circulators with a capacity of 20
gal/min at 10 ft of head and fractional horsepower motors to large
cooling tower pumps with capacities of 50,000 gal/min at 100 ft of
head and equipped with 1500-hp motors. These pumps can be con-
stant speed or variable speed. This chapter provides a physical
description of the various pumps that are popular with HVAC design-
ers for chilled, hot, and condenser water service.

5.2 Physical Description of HVAC Pumps
Centrifugal pumps account for most of the pump applications in the
HVAC industry. Some positive-displacement pumps are found on
HVAC systems, but they are used for specific applications with small
capacities, not for distributing water in hot, chilled, and condenser
water or cooling tower applications. A specific duty for positive-
displacement pumps in the HVAC field is the metering of chemicals
into water systems.
Table 5.1 provides a chart that describes the various types of cen-
trifugal pumps found on HVAC systems. There is not universal agree-
ment on some of the generic names applied to these pumps. For exam-
ple, the double-suction pumps listed are often called horizontal split
case pumps. The words diffuser, axial flow, and turbine are used inter-
changeably for one class of centrifugal pumps; axial flow appears to

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