Envision, Nxw application data cont – WaterFurnace Envision2 NXW Chiller User Manual
Page 13

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ENVISION
2
NXW REVERSIBLE CHILLER INSTALLATION MANUAL
1.6. Insulation
A. Heat pumps are built with factory installed insulation
on any surface that may be subject to temperatures
below the room dew point.
1.7. Brine Applications
A. Applications where the leaving fl uid temperature goes
below 40°F a suitable brine solution must be used.
Failure to do so can cause immediate damage to the
system. The brine must be approved for use with heat
exchangers. Automotive antifreeze solutions are not
suitable for use in brazed plate heat exchangers.
B. The freeze detection must be adjusted appropriately
for brine applications. The brine solution
concentration should be at least 15°F below the
lowest leaving fl uid temperature.
Water Quality Guidelines
Envision
2
NXW Application Data cont.
Surface Condensation Chart
Room Ambient Condition
Surface Temperature
50°F
35°F
0°F
Normal (Max 85°F, 70% RH)
1/2"
3/4"
1"
Mild (Max 80°F, 50% RH)
1/8"
1/4"
1/2"
Severe (Max 90°F, 80% RH)
3/4"
1"
2"
Material
316 Stainless Steel
pH
Acidity/Alkalinity
7 - 9
Scaling
Calcium and
Magnesium Carbonate
(Total Hardness)
less than 350 ppm
Corrosion
Hydrogen Sulfide
Less than 1 ppm
Sulfates
Less than 200 ppm
Chlorine
Less than 0.5 ppm
Chlorides
Less than 300 ppm
Carbon Dioxide
10 - 50 ppm
Ammonia
Less than 20 ppm
Ammonia Chloride
Less than 0.5 ppm
Ammonia Nitrate
Less than 0.5 ppm
Ammonia Hydroxide
Less than 0.5 ppm
Ammonia Sulfate
Less than 0.5 ppm
Total Dissolved Solids (TDS)
1000 - 1500 ppm
LSI Index
+0.5 to -0.5
Iron Fouling
(Biological Growth)
Iron, FE
2
+ (Ferrous)
Bacterial Iron Potential
< 0.2 ppm
Iron Oxide
Less than 1 ppm, above this
level deposition will occur
Erosion
Suspended Solids
Less than 10 ppm and filtered
for max. of 600 micron size
Threshold Velocity
(Fresh Water)
< 6 ft/sec
NOTES: Grains = ppm divided by 17
mg/L is equivalent to ppm
2/22/12