Application Manual

| Infiniti™ K 160-19911 Application Manual
Data subject to change 10.2018 | Bradford White Water Heaters
4.3 DOMESTIC HOT WATER CIRCULATION
System conditions vary and each pump must be sized by
a professional to insure performance.
Refer to pump manufacturers flow vs pressure specifications to
select a pump that can provide adequate flow while
overcoming the pressure loss through the Infiniti® K and the
recirculation loop. Refer to figure 2 to determine pressure loss.
Use only bronze or stainless steel pumps. Do not use
pumps of iron construction as they will oxidize and clog
the inlet filter on the appliance.
• When properly installed in a direct recirculation application
the Infiniti® K will regulate water temperature in a recirculation
loop. A thermostatic mixing valve should be used if your
setpoint is greater than 120°F.
• When the loop temperature is within 1.8°F degrees of setpoint
the pump will turn off.
• When the loop temperature is 1.8°F degrees less than the
setpoint the pump will turn on.
• Infiniti® K pump will also turn off after approximately 1 minute
in cases where there is no flow thru the recirculation loop
such as when a crossover valve is installed at the farthest
fixture. Unit will check for flow after approximately 4 minutes
by operating the pump for 10 seconds in order to determine if
the crossover valve has reopened.
EXAMPLE
• Infiniti® K temperature setting: 120°F
• Pump turn ON temperature </= 118°F
• To minimize energy costs:
i. Insulate all pipes in the recirculation loop.
RECIRCULATION LOOP PRESSURE DROP AT 2GPM
(FEET OF HEAD)
Table 4 Source: 2009 International Plumbing Code
Once the loop head loss has been calculated, use the pump
manufacturer’s performance curves to select the proper potable
water circulator at the required flow rate.
For
other desired gpm flow rates, please consult IPC for appropriate
pressure drop.
EXAMPLE
Sizing a pump for a 2gpm direct DHW recirc system with
an Infiniti® K 199 and have 150 ft total loop length.
HEAD LOSS LOOP COMPONENT
9.00 ft
1.20 ft
5.90 ft
0.24 ft
0.10 ft
0.72 ft
+ 0.18 ft
17.34 ft
Infiniti® K 199 (See Fig.2, page 10)
80 ft of ¾" copper
70 ft of ½" copper return
8 x ¾" 90 elbows
2 x ¾" Tees (branch)
8 x ½" 90 elbows
1 x ½" Tee (branch)
Minimum Pump Head at 2.0 gpm
Material
10 ft Pipe 90˚ Elbow 45˚ Elbow Tee Branch
½" Type L Copper 0.85
0.09 0.05 0.18
¾" Type L Copper 0.15
0.03 0.01 0.05
¾" Pex 0.25
0.02 N/A 0.03
⅝" Pex 0.53 0.04 N/A 0.06
½" Pex 1.3 0.12 N/A 0.18
| Infiniti® K 160-199 Application Manual
Data subject to change 10.2019 | Bradford White Water Heaters
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