WaterFurnace Envision Hydronic (NSW) - Manual (Page 42)

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NSW INSTALLATION MANUAL
Catalog performance can be corrected for antifreeze use. Please use the following table and note the example given.
Antifreeze Correction Example
Antifreeze solution is propylene glycol 20% by weight for the source and methanol 10% for the load. Determine the
corrected heating at 30°F source and 80°F load as well as pressure drop at 30°F for an Envision Series NSW050. Also,
determine the corrected cooling at 90°F source and 50°F load.
The corrected heating capacity at 30°F/80°F would be:
46,700 MBTUH x 0.913 x 0.985 = 41,998 MBTUH
The corrected cooling capacity at 90°F/50°F would be:
44,200 x 0.969 x 0.962 = 41,202 MBTUH
The corrected pressure drop at 30°F and 15 GPM would be:
5.2 psi x 1.270 = 6.60 psi
Antifreeze Correction
Antifreeze Type
Antifreeze %
by wt
Heating Cooling Pressure
Drop Load Source Load Source
EWT - °F [°C] 80 [26.7] 30 [-1.1] 50 [10.0] 90 [32.2] 30 [-1.1]
Water 0 1.000 1.000 1.000 1.000 1.000
Ethylene Glycol
10 0.990 0.973 0.976 0.991 1.075
20 0.978 0.943 0.947 0.979 1.163
30 0.964 0.917 0.921 0.965 1.225
40 0.953 0.890 0.897 0.955 1.324
50 0.942 0.865 0.872 0.943 1.419
Propylene Glycol
10 0.981 0.958 0.959 0.981 1.130
20 0.967 0.913 0.921 0.969 1.270
30 0.946 0.854 0.869 0.950 1.433
40 0.932 0.813 0.834 0.937 1.614
50 0.915 0.770 0.796 0.922 1.816
Ethanol
10 0.986 0.927 0.945 0.991 1.242
20 0.967 0.887 0.906 0.972 1.343
30 0.944 0.856 0.869 0.947 1.383
40 0.926 0.815 0.830 0.930 1.523
50 0.907 0.779 0.795 0.911 1.639
Methanol
10 0.985 0.957 0.962 0.986 1.127
20 0.969 0.924 0.929 0.970 1.197
30 0.950 0.895 0.897 0.951 1.235
40 0.935 0.863 0.866 0.936 1.323
50 0.919 0.833 0.836 0.920 1.399
WARNING: Gray area represents antifreeze concentrations greater than 35% by weight and should
be avoided due to the extreme performance penalty they represent.