Views: 0 Author: Site Editor Publish Time: 2026-01-29 Origin: Site
Free cooling dry coolers can work with existing chiller systems, provided the hydraulic and control integration is correctly designed. In many retrofit projects, the dry cooler is added to reduce chiller operating hours during low ambient temperature conditions, thereby lowering energy consumption and extending chiller lifespan.
Free cooling dry coolers are usually connected in parallel or series with the existing chiller on the condenser water or chilled water side, depending on system design.
The dry cooler operates independently of the chiller when ambient temperature is sufficiently low.
A three-way valve or motorized valve diverts chilled water to the dry cooler.
The chiller is completely shut down during full free cooling operation.
Ideal for data centers, process cooling, and continuous-load systems.
Advantages
Maximum energy savings
Reduced compressor runtime
Simple control logic
The dry cooler pre-cools return water before it enters the chiller.
The chiller still operates but at a reduced load.
Used when ambient temperatures are not low enough for full free cooling.
Advantages
Partial free cooling over a wider temperature range
Improved chiller efficiency (lower condensing temperature)
Free cooling dry coolers are compatible with:
Water-cooled chillers
Air-cooled chillers (on the chilled water loop)
Process chillers
They are commonly applied in:
Data centers
Industrial process cooling
Power electronics and energy storage systems
Plate heat exchanger or integrated coil for hydraulic separation
Proper pump sizing for additional pressure drop
Glycol solution may be required for frost protection
Bypass line for precise temperature control
Integration requires:
Ambient temperature sensors
Supply/return water temperature sensors
Automatic valve and pump control
Seamless changeover logic between free cooling and mechanical cooling
Most modern chillers support BMS or PLC integration, making retrofits straightforward.
Free cooling becomes effective when:
Ambient temperature is below the required supply water temperature
Typical threshold: outdoor temperature 5–10°C lower than chilled water setpoint
Best performance in cold and temperate climates
| Challenge | Solution |
|---|---|
| Freezing risk | Use glycol or drain-back design |
| Flow imbalance | Install balancing valves |
| Control conflicts | Upgrade control strategy |
| Space constraints | Use vertical or remote dry coolers |
Up to 60–80% reduction in chiller energy consumption during winter
Lower maintenance and longer chiller service life
Reduced CO₂ emissions
Fast return on investment, often 1–3 years
Free cooling dry coolers can be successfully integrated with existing chiller systems through proper hydraulic layout, control strategy, and component selection. Whether operating in full free cooling or hybrid mode, they provide a proven and cost-effective way to improve system efficiency without replacing the existing chiller.
