AERCO Esteem O&M Manual - Manual (Page 25)

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Domestic Hot Water System Piping
Domestic Hot Water System Piping
See Figure 9, page 22 for recommended piping
to a DHW system. This recommended piping
configuration ensures priority is given to the
production and recovery of the DHW.
The piping for the DHW is separate from the
boiler system piping and does not require a
primary / secondary piping configuration.
To wire the DHW circulator to the boiler control
module, see Chapter 9 External Wiring.
System Piping - Zone Circulators
Connect the Esteem 399 Low NOx to the sys-
tem piping as shown in Figure 10 page 23 when
zoning with zone circulators.
The installer must provide a separate circula-
tor for each zone of space heating as well as
the boiler circulator.
N
OTICE
To ensure an adequate fl ow rate through
the Esteem 399 Low NOx , the boiler
supply and return piping size must be a
minimum 1-1/2 inch for the Esteem 399
Low NOx .
System Piping - Zone Valves
Connect the Esteem 399 Low NOx to the system
piping as shown in Figure 11, page 23 when zon-
ing with zone valves. The primary / secondary
piping ensures that the boiler loop has sufficient
flow.
N
OTICE
To ensure an adequate fl ow rate through
the Esteem 399 Low NOx , the boiler
supply and return piping size must be
a minimum of 1-1/2 inch for the Esteem
399 Low NOx .
System Piping - Through Boiler
In new or retrofit applications in which primary/
secondary arrangement is not used, the Esteem
399 Low NOx allows this flexibility due to a lower
boiler pressure drop, see Graph 2 and Graph 3
on page 91.
Figure 12, page 24 illustrates a multiple zone
valve system with a single system/boiler circu-
lator. A by-pass loop with a pressure differential
valve must be installed on the system piping.
Figure 13, page 24 illustrates a single zone utilizing
the boiler circulator as the system circulator.
System Piping - Radiant Heating
The heat exchanger design of the Esteem
399 Low NOx allows operation in a condens-
ing mode. This feature requires no return
water temperature regulation in radiant heat-
ing applications.
Esteem 399 Low NOx can maintained the boil-
er water supply temperature, eliminating the
need for a mix system to achieve the desired
temperature.
A high temperature limit as shown in Figure
14, page 25 should be installed to ensure that
the primary supply temperature does not
exceed the maximum allowable temperature
for the radiant tubing.
The addition of the high temperature limit is
important if the Esteem 399 Low NOx is con-
nected to a domestic hot water system, which
requires a high primary supply water tempera-
ture.
Size the system piping and circulator to provide
the flow needed for the radiant system.
N
OTICE
The Esteem 399 Low NOx supply and
return piping must be a minimum of
1-1/2 inch .
GF-125