Lochinvar Copper-Fin II CX401, Designer'S Manual, Page: 25 / 32

AIR REMOVAL
An air separation device should be placed in
the installation piping, on the suction side of
the system pump, to eliminate trapped air in
the system. Locate a system air vent at the
highest point in the system. Additionally, a
properly sized expansion tank is required. Air
charged, diaphragm-type compression tanks
are common. The expansion tank
must be
installed close to the boiler and on the suction
side of the system pump to ensure proper
operation.
TEMPERATURE/PRESSURE
GAUGE
This boiler is equipped with a dial type
temperature/pressure gauge. This gauge is
factory installed in the outlet side of the heat
exchanger. The gauge has one scale for
reading system pressure and a separate scale
for water temperature in degrees Fahrenheit.
LOW SYSTEM WATER
VOLUME
System run time is very important to overall
operating efficiency of the boiler. Short
cycling of the boiler creates problems with
condensation in the vent stack,
condensation on the heat exchanger,
system temperature spikes, and mechanical
component failures. To prevent short cycling
of the boiler, it is important to limit the boiler
cycles to six or fewer per hour.
A Buffer Tank is an effective way to
enhance a small system load and increase
heating system efficiency. Buffer tanks add
water volume to the system and act as a
flywheel to absorb the additional Btu's
provided by the boiler when only a single
zone of a large system is calling for heat.
To calculate the proper buffer tank size for
a multiple zone system:
(Run Cycle) (Output - Minimum System Load)
(Temp. Rise) (8.33)(60 Min.)
L o c h i n v a r
D E S I G N E R
’
S G U I D E C O P P E R
-
F I N I I B O I L E R
6 1 5 - 8 8 9 - 8 9 0 0
23
(FIG. 25) BUFFER TANK PIPING
EXAMPLE OF
BUFFER TANK
APPLICATIONS
CHN1261 Boiler
Run Cycle = 10 Min.
Temp. Rise = 10°F
Min. Load =
100,000Btu/hr
(10)(1,000,000 -
100,000)
divided by
40 x 8.33 x 60
= 485 Gallons