Lochinvar 1 - Manual (Page 30)

30
Installation & Operation Manual
Figure 5-3 Pump Configuration
5
Hydronic piping
Hot Water Generator pump sizing
The SYNC has two (2) heat exchangers that require two (2) individual pumps for proper installation in the boiler loop and an
additional two (2) pumps for the Hot Water Generator loop.
Hot Water Pump Head Loss = Ft. of Head for Heat Exchanger 1 (at required flow) + Ft. of Head for the Hot Water Generator
(at 2 X the flow of Heat Exchanger 1)
Example:
Boiler: SB1500
A T of 30° requires a flow through each heat exchanger of 51 GPM. The heat exchanger head loss is 18 ft. of head (see Table 5A).
Coupled with a Lochinvar Hot Water Generator with a 8-42 (diameter-length) tube bundle the calculated pressure drop is
1.2 Ft. of Head at 102 GPM.
Hot Water Pump Head Loss = 18 Ft/Hd (51 GPM) + 1.2 Ft/Hd (102 GPM) = 19.2 Ft/Hd
A pump will need to be selected to flow 51 GPM with a head loss of 19.2 Ft/Hd.
Figure 5-2 Boiler Schematic
HEAT EXCHANGER 1
HOT WATER PUMP
HEAT EXCHANGER 2
HOT WATER PUMP
HEAT EXCHANGER 2
BOILER PUMP
HEAT EXCHANGER 1
BOILER PUMP
102 GPM
51 GPM
102 GPM
51 GPM
TO SYSTEM FROM SYSTEM
HOT WATER
GENERATOR
AIR COVER
OK
TO BOILER
INLETS
FROM SYSTEM
NO
TO BOILER
INLETS
FROM SYSTEM