AERCO AM Series Boiler User Manual - Manual (Page 46)

AM Series Boilers and Water Heaters
CHAPTER 3 – INSTALLATION
Page 46 of 156 AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 OMM-0100_0B
PRI - 07/14/14
Ph.: 800-526-0288
GF-146
3.12.7 Water Chemistry – Water Heaters
The water heater pressure drops (see Figure 3-14) are based on potable water with a hardness
of 5 to 25 grains per gallon and a total dissolved solids not exceeding 350 ppm. Consult the
manufacturer when heating potable water exceeding these specifications.
Heating of high hardness and/or high total dissolved solids water increases the pressure drops
and may require a larger circulating pump, and a revised temperature rise specification based
on the water chemistry of the water to be heated.
Figure 3-14: AM Series Water Heater Water Pressure Drop Graph
Size your water system according to the following hardness guidelines to prevent scaling of the
heat exchanger. See Figure 3-15 for corresponding water flow.
• If the water is 5 to 8 grain per gallon, this is SOFT water and you have to size the system
for a 4 ft/sec minimum water velocity.
• If the water is 8 to 18 grain per gallon, this is NORMAL water and you have to size the
system for a 4 to 8 ft/sec minimum water velocity.
• If the water is 18 to 23 grain per gallon, this is HARD water and you have to size the
system for a 8 ft/sec minimum water velocity.