13
Flow Controller 3
R e v. : F e b u r a r y 9 , 2 0 1 6
-50°F
-40°F -30°F -20°F -10°F
0°F
10°F
20°F
30°F
40°F
50°F
0.960
0.965
0.970
0.975
0.980
0.985
0.990
0.995
1.000
Low Temperature Protection
Specific Gravity
-45.6°C
-40°C
-34.4°C
-28.9°C
-23.3°C
-17.8°C
-12.2°C
-6.7°C
-1.1°C
4.4°C
10°C
1.00
1.01
1.02
1.03
1.04
1.05
1.06
1.07
Low Temperature Protection
Specific Gravity
-40°F
-30°F
-20°F
-10°F
0°F
10°F
20°F
30°F
40°F
-40°C -34.4°C -28.9°C -23.3°C -17.8°C -12.2°C -6.7°C -1.1°C
4.4°C
0.975
0.980
0.985
0.990
0.995
1.000
-5°F
0°F
5°F
10°F
15°F
20°F
25°F
30°F
35°F
1.7°C
-1.1°C
-3.9°C
-6.7°C
-9.4°C
-12.2°C
-15.0°C
-17.8°C
-20.6°C
Low Temperature Protection
Antifreeze Selection
Fluid Volume (gal [liters] per 100’ [30 meters) Pipe)
Pipe
Size
Volume (gal) [liters]
Copper
1”
4.1 [15.3]
1.25”
6.4 [23.8]
2.5”
9.2 [34.3]
Rubber Hose
1”
3.9 [14.6]
Polyethylene
3/4” IPS SDR11
2.8 [10.4]
1” iPS SDR11
4.5 [16.7]
1.25” IPS SDR11
8.0 [29.8]
1.5” IPS SDR11
10.9 [40.7]
2” IPS SDR11
18.0 [67.0]
1.25” IPS SCH40
8.3 [30.9]
1.5” IPS SCH40
10.9 [40.7]
2” IPS SCH40
17.0 [63.4]
Unit Heat Exchanger
Typical
1.0 [3.8]
Flush Cart Tank
10” Dia x 3ft tall
[254mm x 91.4cm tall]
10 [37.9]
Table 3: Fluid Volume
Chart 1a: Methanol Specific Gravity
Chart 1b: Propylene Glycol Specific Gravity
Chart 1c: Ethanol Specific Gravity
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WARNING!
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WARNING!
Always dilute alcohols with water (at least 50%
solution) before using. Alcohol fumes are flammable and
can cause serious injury or death if not handled properly.
General
In areas where minimum entering loop temperatures drop
below 40°F [4.4°C] or where piping will be routed through
areas subject to freezing, antifreeze is needed. Alcohols
and glycols are commonly used as antifreeze solutions.
Your local representative should be consulted for the
antifreeze best suited to your area. Freeze protection should
be maintained to 15°F [8.5°C] below the lowest expected
entering loop temperature. For example, if 30°F [-1°C] is the
minimum expected entering loop temperature, the leaving
loop temperature would be approximately 22 to 25°F [-5.5
to -3.9°C] and freeze protection should be at 15°F [-9.5°C].
Calculations are as follows:
30°F - 15°F = 15°F [-1°C - 8.5°C = -9.5°C]
All alcohols should be premixed and pumped from a
reservoir outside of the building when possible or introduced
under water level to prevent fuming. Initially calculate the
total volume of fluid in the piping system using Table 3.
Then use the percentage by volume shown in Table 4 for the
amount of antifreeze. Antifreeze concentration should be
checked from a well mixed sample using a hydrometer to
measure specific gravity.
Antifreeze Characteristics
Selection of the antifreeze solution for closed loop earth
coupled systems requires the consideration of many
important factors which have long-term implications on the
performance and life of the equipment. Each area of concern
leads to a different “best choice” of antifreeze. The fact is
that there is no “ideal” antifreeze and any choice will require
compromises in one area or another. Some of the factors
to consider are safety, thermal performance, corrosiveness,
local codes, stability, convenience, and cost.
