AAON SB-018 - Manual (Page 22)

22
Table 3 - Condenser Water Connections
Model (SB-)
Supply and Return
Connection Size
(in. FPT)
003, 004, 005 1
006, 007, 009, 010 1 1/4
014, 016, 018 1 1/2
Condenser water pump must be field sized
and installed between the cooling tower or
geothermal wellfield and self contained unit.
System should be sized in accordance with
the ASHRAE Handbook. Use engineering
guidelines to maintain equal distances for
supply and return piping and limit bend
radiuses to maintain balance in the system.
Balancing valves, permanent thermometers
and gauges may be required.
Before connection to the unit, the condenser
water system should be flushed to remove
foreign material that could cause condenser
fouling. Install a screen strainer with a
minimum of 20 Mesh ahead of the
condenser inlet to prevent condenser fouling
and internal tube damage. Mineral content
of the condenser water must be controlled.
All make-up water has minerals in it and as
the water is evaporated in the cooling tower,
these minerals remain. As the mineral
content of the water increases, the
conductivity of the water increases.
Field provided and installed water treatment
program must be compatible with stainless
steel, copper, aluminum, ABS plastic, and
PVC. Batch feed processes should never be
used as concentrated chemicals can cause
corrosion. Never use hydrochloric acid
(muriatic acid) or chlorine as it will corrode
stainless steel.
Water loop piping runs through unheated
areas or outside the building should be
insulated.
NOTE: Ball valves should be installed in
the condenser water supply and return lines
for unit isolation and water flow balancing.
All manual flow valves should be of the ball
valve design. Globe or gate valves should
not be used due to high pressure drops and
poor throttling characteristics.
Pressure and temperature ports are
recommended in condenser water supply
and return lines for system balancing. These
openings should be 5 to 10 pipe diameters
from the unit water connections. To allow
for mixing and temperature stabilization,
wells in the water piping should extend at
least ½ pipe diameter into the pipe.
WATER PIPING
Follow national and local codes when
installing water piping. Connections
to the unit should incorporate
vibration eliminators to reduce noise
and vibration and shutoff valves to
facilitate servicing. Supply and return
water piping must be at least as large
as the unit connections and larger
depending on length of runs, rise and
bends.
CAUTION
Installing contractor is responsible for
properly sizing and installing water
system components. Improper fluid
flow due to valves, piping, or
improper pump operation may result
in unacceptable unit operation and
void warranty.
CAUTION