Lochinvar Power-Fin Designer's Manual page 24

Designer's Guide / Power-fin Water Heater
FACTORY SUPPLIED PUMP
Again, the circulation pump in the water heater loop is factory supplied. It is sized based on a
given amount of pipe and so many fittings. The standard pump is based on 45 feet of straight
pipe with:
6 – 90° Elbows
2 – Unions
Did you Know?
THE POWER-FIN COMES WITH INTERMITTENT PUMP CONTACTS AS STANDARD EQUIPMENT. THE
CONTACTS WILL OPERATE THE RECIRCULATION PUMP ON EACH CALL FOR HEAT AND THE PUMP
DELAY TIMING IS FIELD PROGRAMMABLE.
For each fitting in excess of those shown above, deduct 6.5 feet from the straight pipe. If your
system exceeds this math, the pump may be increased in size to provide the necessary flow.
Please consult Lochinvar Technical Service for details.
MULTIPLE HEATERS / MULTIPLE TANKS
The second most common design is for multiple water
heaters piped to multiple tanks. Multiple heaters
provide water heating redundancy. Multiple tanks
increase storage on capacity in easy to manage
vessels.
The key element in having multiple water heaters is you
have multiple pumps; multiple pumps that share
common piping. When that happens, the pipe
diameters MUST be increased to accommodate the
increased flow.
Here are the common manifold pipe sizes and the
combined flow rates for the Power-fin product family.
Power-fin 0502, 0752, 1002 & 1302
Number of
Units
2
3
4
5
6
7
8
Regardless of the number of tanks, when you have more than one heater, the common pipe size
must increase because the number of pumps increased. However, if you have multiple tanks but
only one heater, you do not have to increase the common manifold size because you only have
one pump.
2 – Ball Valve
1 – Cold Water Tee
Combined Common Manifold
GPM Pipe Diameter
150 3-1/2"
225 4"
300 5"
375 6"
450 6"
525 6"
600 7"
Power-fin 1501, 1701 & 2001
Number of Combined
Units GPM
2 180
3 270
4 360
5 450
6 540
7 630
8 720
24
LOCHINVAR CORPORATION
300 MADDOX SIMPSON PKWY
LEBANON, TN 37090
www.lochinvar.com
Reference Drawing A3 – Page 39
Common Manifold
Pipe Diameter
4"
5"
6"
6"
6"
7"
7"