Evaporative cooling occurs with the evaporation of a small portion of water. The rising concentration of dissolved solids, means further airborne impurities and biological contaminants enter the recirculating water, as the evaporative cooler ‘washes the air’.
Failure to control these impurities and contaminants will see them cause scaling, corrosion, sludge or biological fouling. For optimal heat transfer efficiency, maximum service life and minimized operating costs, the quality of the make-up and recirculating water must be ensured. You can find the water quality guidelines for all BAC material options in the paragraph "Water quality" of BAC's application guidelines.
Good water care is also vital for avoiding harmful bacterial proliferation, including legionella, in the recirculating water. BAC offers automatic water treatment packages or filtration systems to control corrosion, scaling, fouling and microbiological growth.
Circulated water quality guidelines
Baltiplus 800, 810TM Protection | |
| pH | 7.0 to 9.0 |
| pH during initial passivation | below 8.2 |
| Total hardness (as CaCO3) | 70 to 600 mg/l |
| Total alkalinity (as CaCO3) | 500 mg/l max. |
| Total dissolved solids | 1250 mg/l max. |
| Conductivity | 2000 µS/cm |
| Chlorides | 200 mg/l max. |
| Sulfates* | 200 mg/l max.* |
| Total suspendid solids | 25 mg/l max. |
| Chlorination (as free chlorine): continuous | 1 mg/l max. |
| Chlorination (as free chlorine): batch dosing for cleaning & disinfection | 5-15 mg/l max. for 6 hours max. 25 mg/l max. for 2 hours max. 50 mg/l max. for 1 hour max. |
SST 304 | |
| pH | 6.5 to 9.2 |
| pH during initial passivation | below 8.2 (for units with HDG coil only) |
| Total hardness (as CaCO3) | 70 to 750 mg/l |
| Total alkalinity (as CaCO3) | 600 mg/l max. |
| Total dissolved solids | 2050 mg/l max. |
| Conductivity | 3300 µS/cm |
| Chlorides | 300 mg/l max. |
| Sulfates* | 350 mg/l max.* |
| Total suspendid solids | 25 mg/l max. |
| Chlorination (as free chlorine): continuous | 1 mg/l max. |
| Chlorination (as free chlorine): batch dosing for cleaning & disinfection | 5-15 mg/l max. for 6 hours max. 25 mg/l max. for 2 hours max. 50 mg/l max. for 1 hour max. |
Pultruded Composite | |
| pH | 6.5 to 9.5 |
| pH during initial passivation | not applicable |
| Total hardness (as CaCO3) | 750 mg/l max. |
| Total alkalinity (as CaCO3) | 600 mg/l max. |
| Total dissolved solids | 2500 mg/l max. |
| Conductivity | 4000 µS/cm |
| Chlorides | 750 mg/l max. |
| Sulfates* | 750 mg/l max.* |
| Total suspendid solids | 25 mg/l max. |
| Chlorination (as free chlorine): continuous | 2 mg/l max. |
| Chlorination (as free chlorine): batch dosing for cleaning & disinfection | 5-15 mg/l max. for 6 hours max. 25 mg/l max. for 2 hours max. 50 mg/l max. for 1 hour max. |
SST 304 and SST 316 with HDG coil | SST 316 (with SST 316 coil) | |
| pH | 6.5 to 9.2 | 6.5 to 9.5 |
| pH during initial passivation | below 8.2 (for units with HDG coil) | not applicable |
| Total hardness (as CaCO3) | 70 to 750 mg/l | 750 mg/l max. |
| Total alkalinity (as CaCO3) | 600 mg/l max. | 600 mg/l max. |
| Total dissolved solids | 2050 mg/l max. | 2500 mg/l max. |
| Conductivity | 3300 µS/cm | 4000 µS/cm |
| Chlorides | 300 mg/l max. | 750 mg/l max. |
| Sulfates* | 350 mg/l max.* | 750 mg/l max. |
| Total suspendid solids | 25 mg/l max. | 25 mg/l max. |
| Chlorination (as free chlorine): continuous | 1.5 mg/l max. | 2 mg/l max |
| Chlorination (as free chlorine): batch dosing for cleaning & disinfection | 5-15 mg/l max. for 6 hours max. 25 mg/l max. for 2 hours max. 50 mg/l max. for 1 hour max. | 5-15 mg/l max. for 6 hours max. 25 mg/l max. for 2 hours max. 50 mg/l max. for 1 hour max. |
* Higher concentrations of sulfates allowed provided the sum of chlorides +sulfates paramaters does not exceed 400 mg/l for Baltiplus 800, 650 mg/l for SST 304 and 1500 mg/l for SST 316/Pultruded.
Contact your local BAC representative for more information.