Conair VL Series - Manual (Page 37)

Page: 37 UGH020/0301 VL Series Portable Chillers, 0.25 to 1.5 Tons
8.3 WATER QUALITY CONTROL
A. Lack of, as well as, improper water treatment can damage the
chilling unit. The services of a competent water treatment specialist
should be obtained and their recommendations followed. It is the
equipment owner’s responsibility to prevent damage from foreign
material or inadequate water treatment.
B. The two main things to consider for water treatment in chillers are
corrosion and organism growth. Proper chemical treatment can
control PH levels and algae growth. An alternative to chemical
treatment is the addition of 20% inhibited propylene glycol to the
water. This will help prevent organism growth and coat the heat
transfer surfaces with corrosion inhibitor.
8.4 INHIBITED PROPYLENE GLYCOL
A. The use of a water-glycol
mixture is needed when
the operator desires a
process temperature
below 48°F. Freeze
protection is required so
ice crystals do not form
and cause severe damage
to both the water and
refrigeration system.
B. CHOOSING THE PROPER
GLYCOL:
1. For getting the most efficiency from your system, a
propylene glycol such as “DowFrost” is a must. DowFrost
contains special corrosion inhibitors for low system
maintenance and better transfer capabilities than normal
glycols. It also has a much longer fluid life up, to 20 years
in some cases.
2. SOURCES OF INHIBITED PROPYLENE GLYCOLS: for a
complete literature package, material, safety data sheets
and purchasing information, contact the following:
DOW CHEMICAL 1-800-447-4369
(Canada 1-800-363-6250)
Dowfrost inhibited propylene glycol
MONSANTO CHEMICAL 1-800-459-2665
Monsanto FS inhibited propylene glycol
FREEZING POINTS FOR
WATER/PROPYLENE GLYCOL SOLUTIONS
˚F
FREEZE POINT
32
25
10
0
-10
-30
-60
0
-3.9
-12.2
-17.8
-23.3
-34.4
-51.4
˚C WATER GLYCOL*
0
10
20
30
40
50
60
100
90
80
70
60
50
40
PERCENTAGE OF
*PROPLYLENE GLYCOL
NOTE: GLYCOL FREEZE POINT MUST BE 25˚F BELOW
LOWEST SETPOINT