8
NSKW INSTALLATION MANUAL
General
NSKW heat pumps may be successfully applied in a wide
range of residential and light commercial applications. It
is the responsibility of the system designer and installing
contractor to ensure that acceptable water quality is
present and that all applicable codes have been met in
these installations. Failure to adhere to the guidelines in the
water quality table could result in loss of warranty.
Water Treatment
Do not use untreated or improperly treated water.
Equipment damage may occur. The use of improperly
treated or untreated water in this equipment may result in
scaling, erosion, corrosion, algae or slime. The services of a
qualified water treatment specialist should be engaged to
determine what treatment, if any, is required. The product
warranty specifically excludes liability for corrosion,
erosion or deterioration of equipment.
The heat exchangers and water lines in the units are copper
or cupronickel tube. There may be other materials in the
Material
Copper
90/10 Cupronickel
316 Stainless Steel
pH
Acidity/Alkalinity
7 - 9
7 - 9
7 - 9
Scaling
Calcium and
Magnesium Carbonate
(Total Hardness)
less than 350 ppm
(Total Hardness)
less than 350 ppm
(Total Hardness)
less than 350 ppm
Corrosion
Hydrogen Sulfide
Less than 0.5 ppm (rotten egg
smell appears at 0.5 ppm)
10 - 50 ppm
Less than 1 ppm
Sulfates
Less than 125 ppm
Less than 125 ppm
Less than 200 ppm
Chlorine
Less than 0.5 ppm
Less than 0.5 ppm
Less than 0.5 ppm
Chlorides
Less than 20 ppm
Less than 125 ppm
Less than 300 ppm
Carbon Dioxide
Less than 50 ppm
10 - 50 ppm
10 - 50 ppm
Ammonia
Less than 2 ppm
Less than 2 ppm
Less than 20 ppm
Ammonia Chloride
Less than 0.5 ppm
Less than 0.5 ppm
Less than 0.5 ppm
Ammonia Nitrate
Less than 0.5 ppm
Less than 0.5 ppm
Less than 0.5 ppm
Ammonia Hydroxide
Less than 0.5 ppm
Less than 0.5 ppm
Less than 0.5 ppm
Ammonia Sulfate
Less than 0.5 ppm
Less than 0.5 ppm
Less than 0.5 ppm
Total Dissolved Solids (TDS)
Less than 1000 ppm
1000 - 1500 ppm
1000 - 1500 ppm
LSI Index
+0.5 to -0.5
+0.5 to -0.5
+0.5 to -0.5
Iron Fouling
(Biological Growth)
Iron, FE
2
+ (Ferrous)
Bacterial Iron Potential
< 0.2 ppm
< 0.2 ppm
< 0.2 ppm
Iron Oxide
Less than 1 ppm, above this
level deposition will occur
Less than 1 ppm, above this
level deposition will occur
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
Less than 10 ppm and filtered
for max. of 600 micron size
Less than 10 ppm and filtered
for max. of 600 micron size
Threshold Velocity
(Fresh Water)
< 1.8 m/sec
< 1.8 m/sec
< 1.8 m/sec
NOTES:
Grains = ppm divided by 17
mg/L is equivalent to ppm
2/22/12
Water Quality
building’s piping system that the designer may need to take
into consideration when deciding the parameters of the
water quality.
If an antifreeze or water treatment solution is to be used,
the designer should confirm it does not have a detrimental
effect on the materials in the system.
Contaminated Water
In applications where the water quality cannot be held to
prescribed limits, the use of a secondary or intermediate
heat exchanger is recommended to separate the unit from
the contaminated water.
The following table outlines the water quality guidelines
for unit heat exchangers. If these conditions are exceeded,
a secondary heat exchanger is required. Failure to supply
a secondary heat exchanger where needed will result in a
warranty exclusion for primary heat exchanger corrosion or
failure.
Water Quality Guidelines
