DOWTHERM SR-1 and DOWFROST HD Heat Transfer Fluids In ...

PRODUCT DESCRIPTIONS AND BENEFITS
DOWTHERM SR-1 fluid
DOWTHERM SR-1 heat transfer
fluid is an industrially inhibited
ethylene glycol-based heat transfer
fluid. The formulation consists of
95.4% ethylene glycol with the
balance corrosion inhibitors, water
and dye. The fluid is dyed fluorescent
pink for leak detection
purposes.
DOWFROST HD fluid
DOWFROST HD heat transfer
fluid is an industrially inhibited
propylene glycol-based heat
transfer fluid. The formulation
consists of 94% propylene glycol
with the balance corrosion inhibitors,
water and dye. The fluid is
dyed bright yellow to aid in leak
detection.
Both fluids are typically used in a
25-30% solution with water as the
heat transfer medium in ice
storage systems. Typical specifications
of these fluids are given in
Table 1.
Specially formulated inhibitors
prevent system corrosion
Dow glycol-based fluids contain
specially formulated packages of
2
industrial inhibitors that help
prevent corrosion of metal in two
ways.
First, they passivate the surface of
metals, reacting with the surface
to prevent acids from attacking it.
Unlike inhibitors used in some
other fluids, Dow inhibitors
perform this passivation process
without fouling heat transfer
surfaces.
Second, the inhibitors buffer any
acids formed as a result of glycol
oxidation. All glycols produce
organic acids as degradation
products. This degradation process
is accelerated in the presence of
oxygen and/or heat. Left in
solution, such acids lower pH and
contribute to corrosion. Properly
formulated inhibitors, such as
those in DOWTHERM and
DOWFROST fluids, neutralize
these acids.
These inhibitors are long lasting
and usually do not need supplemental
additions of other water
treatment chemicals. All the
necessary additives are already
contained in the DOWTHERM
SR-1 or DOWFROST HD fluids.
Table 1 –– Typical Product Physical Properties
Low freezing points prevent
chiller freeze-ups
DOWTHERM SR-1 and
DOWFROST HD also provide a
reduction in the freezing point of
the solution to allow the manufacture
of ice in the ice storage
system. Generally, the
DOWTHERM SR-1 or
DOWFROST HD solution is
chilled to between 20 and 26°F to
make ice. A 25% solution of
DOWTHERM SR-1 fluid has a
freezing point below 14°F, while a
similar solution of DOWFROST
HD fluid has a freezing point
below 16°F. Both provide an
adequate margin of safety below
the typical operating temperature
to prevent chiller freeze-ups.
Approved by ice storage
system OEMs
Following are some of the ice
storage system manufacturers who
have approved the use of one or
both DOWTHERM SR-1 and
DOWFROST HD heat transfer
fluids in their ice storage systems:
■ Baltimore Air Coil
■ Calmac
■ Cryogel
■ Dunham-Bush
■ Fafco
DOWTHERM SR-1 DOWFROST HD
Ethylene Glycol-Based Propylene Glycol-Based
Heat Transfer Fluid Heat Transfer Fluid
Composition (% by weight)
Glycol 95.4 94.0
Inhibitors & Water 4 . 6 6 . 0
Color Fluorescent Pink Bright Yellow
Specific Gravity (at 60/60°F) 1.1250 –– 1.1350 1.053 –– 1.063
pH of Solution (50% glycol) 9.0 –– 9.6 9.5 –– 10.5
Reserve Alkalinity (min.) 11.0 ml 15.0 ml