HWM-H-IOM (10/14)
Page 16
Figure 8a 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/DWM
Models
Minimum Nominal Type L
Hard Copper Pipe and
Fittings, Inches
ETI Strainer
Model, Size
-018 (18,000)
-1836
3/4
ST-1836
1in. FPT
-024 (24,000)
3/4
-030 (30,000)
1
-036 (36,000)
1
-042 (42,000)
-4248
1-1/2
ST-4272
1-1/2in FPT
-048 (48,000)
1-1/2
-054 (54,000)
-5472
1-1/2
-060 (60,000)
1-1/2
-072 (72,000)
1-1/2
Figure 8a. Minimum Water Pipe, Fitting and Strainer Sizes to Storage Water Heater
The flow meter illustrated in Figure 4 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 8b) may be purchased at http://www.buygpi.com/eti-a1-116000-
1.aspx.
Figure 8b. Flowmeter Kit
F. Refrigerant Piping
Refrigerant piping connections and line set sizes are listed in Figure 7.
IMPORTANT!
Maximum hot water temperature, from the Hydronic Water Module is 110°F.