Solution/Wt.
15
20
30
40
(Percent)→
(180-190 degrees F)
0.98
0.99
1.00
1.00
Viscosity centipoises (mPas)
30
2.8
3.2
4.0
5.5
40
2.2
2.6
3.2
4.4
180
0.46
0.52
0.60
0.70
190
0.48
0.48
0.58
0.67
2.8.3.2 FLOW-GPM: Use the following correction factors to determine the
solution flows. Use this flow in the equipment schedule.
Table 2-4 Ethylene Glycol Solution; Weight Correction Factors
Solution/Wt.
15
20
35
40
(Percent)→
0-40 degrees C
1.03
1.04
1.09
1.16
(30-40 degrees F)
82-88 degrees C
1.04
1.04
1.06
1.10
(180-190 degrees F)
Example: 200 GPM water at 40 ft head and a 40 percent solution wt at 30
degrees F
Flow Rate = 200 x 1.16 = 232 GPM
2.8.3.3 PRESSURE DROP (HEAD): The total head for the solution is as follows.
Use this value in the equipment schedule.
(a) The following multiplier factors applied to the head calculated for the
water flow will give the increased head due to the increase in solution flow.
Note that the corrections for viscosity must also be included in the head
calculations. See paragraph (b) below.
Table 2-5 Pump Head Correction Factors For Increased Flow
Solution/Wt
15
20
35
40
(Percent)→
0-40 degrees C
1.06
1.08
1.19
1.35
(30-40 degrees F)
82-88 degrees C
1.08
1.08
1.12
1.21
(180-190 degrees F)
Pressure drop = 40 x 1.35 = 54 feet of water
(b) The following multiplier factors applied to head calculated for the
solution flow Item (a), will give the total head for the solution.
HVAC DESIGN MANUAL
2-19
HVAC SYSTEMS AND EQUIPMENT
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