HWM-407CH-IOM (09/13)
Page 17
Figure 10a lists the minimum nominal Type L hard copper pipe and fitting sizes, and the
strainer required for the primary circuit between the hot water module (HWM) and the
storage water heater.
Compressor Unit Size
& Capacity, BTUH
HWM Models
Minimum Nominal Type L
Hard Copper Pipe and
Fittings, Inches
ETI Strainer
Model, Size
-018 (18,000)
-18B
3/4
ST-1836
1in FPT
-024 (24,000)
-24B
3/4
-030 (30,000)
-30B
1
-036 (36,000)
-36B
1
-042 (42,000)
-42B
1-1/2
ST-4272
1-1/2in FPT
-048 (48,000)
-48B
1-1/2
-060 (60,000)
-60B
1-1/2
-072 (72,000)
-72B
1-1/2
Figure 10a. Minimum Water Pipe, Fitting and Strainer Sizes to Storage Water Heater
The flow meter illustrated in Figure 5 is an important component of the system to (1)
commission the performance of the system at startup and (2) determine when maintenance
to the system strainer and/or HWM heat exchanger is required. (See Maintenance in
Section 7.)
ETI part number ETI-A1-116000-1 flowmeter kit has a range of 5-50 GPM and can be field
calibrated for the appropriate antifreeze mixture for the specific application. The kit includes
the flowmeter and the 5 gallon calibration container.
The flow meter kit (see Figure 10b) may be purchased at
http://www.buygpi.com/eti-a1-
116000-1.aspx
.
Figure 10b. Flowmeter Kit
F. Refrigerant Piping
Refrigerant piping connections and line set sizes are listed in Figure 9.
