Lochinvar 81 - 286 - Manual (Page 36)

36
Installation & Operation Manual
6
Hydronic piping
13. Indirect water heaters:
The Knight boiler may be piped to an indirect water
heater to heat domestic hot water with the space heat
transfer medium. As depicted on pages 39 through 45
there are two options when utilizing an indirect water
heater.
A. The space heating piping will branch off to flow the
space heat transfer medium through a single wall
heat exchanger coil inside the indirect water heater.
B. The indirect water heater is connected to the system
supply piping. A pump controlled by the Knight
boiler’s control will regulate the flow of water
through the indirect water heater. The indirect water
heater’s temperature will be regulated by the Knight
boiler’s control.
The Knight boiler is pre-configured to control the
operation of the DHW pump with Domestic Hot Water
Prioritization programming. The DHW programming is
designed to control and balance the space heating
demand by switching between DHW and space heating.
Lochinvar offers the Squire which is a series of indirect
water heaters. The Squire features a stainless steel vessel
with a single wall stainless steel heat exchanger.
ƽ WARNING The National Standard Plumbing Code, the
National Plumbing Code of Canada and the
Uniform Plumbing Code limit the pressure
of the heat transfer fluid to less than the
minimum working pressure of the potable
water system up to 30 psi maximum. Also,
the heat transfer fluid must be water or
other non-toxic fluid having a toxicity of
Class 1, as listed in Clinical Toxicology of
Commercial Products, 5
th Edition.
14. Y-Strainer:
Field supplied. A Y-strainer or equivalent multipurpose
strainer is recommended at the inlet of the heat exchanger
to remove system particles from older hydronic systems and
protect newer systems.
CAUTION
It is up to the installer to ensure the
minimum system flow is not less than the
minimum boiler flow at any time.
Circulator sizing
The Knight boiler heat exchanger does have a pressure drop,
which must be considered in your system design. Refer to the
graph in FIG. 6-3 for pressure drop through the Knight boiler
heat exchanger.
INDIRECT
DOMESTIC
HOT WATER
TANK
TO FLOOR
DRAIN
DOMESTIC HOT
WATER PUMP
BOILER
PUMP
SYSTEM
PUMP
Y-STRAINER
(RECOMMENDED)
DRAIN
(TYPICAL)
TO
SY
ST
EM
FR
OM
SY
ST
EM
FR
OM
TO
SYSTEM SENSOR
AIR SEPARATOR
Figure 6-2A Near Boiler Piping w/Y-Strainer
Y-STRAINER
(RECOMMENDED)
FILL VALVE
EXPANSION TANK
DRAIN VALVE
SYSTEM SENSOR
AIR SEPARATOR
LOW LOSS HEADER
(TYPICAL)
AIR VENT VALVE
DRAIN
(TYPICAL)
TO
SY
ST
EM
FR
OM
SY
ST
EM
FR
OM
TO
INDIRECT
DOMESTIC
HOT WATER
TO FLOOR
DRAIN
BOLIER PUMP
Figure 6-2B Near Boiler Piping w/Low Loss Header
Near boiler piping connections