Free Cooling Dry Cooler Combine with Rear Door Heat Exchanger Water Cooling

A Free Cooling Dry Cooler combined with a Rear Door Heat Exchanger (RDHX) is an energy-efficient water cooling system commonly used in data centers or high-density server rooms. It integrates two key cooling technologies to remove heat from IT equipment efficiently. 

1. Components

1. Rear Door Heat Exchanger (RDHX):

• Mounted on the back of server racks.

• Acts like a radiator for the hot air leaving the servers.

• Uses chilled water to absorb heat directly at the source, reducing hot air recirculation in the room.

2. Free Cooling Dry Cooler:

• A large air-cooled heat exchanger outside the data center.

• Cools the circulating water using ambient air, without relying on energy-intensive compressors.

• Provides “free cooling” whenever the outside air is cool enough.

2. How It Works Together

1. RDHX captures heat from the hot server exhaust and transfers it to water circulating in a closed loop.

2. The heated water flows to the Dry Cooler.

3. The Dry Cooler dissipates the heat to ambient air.

4. Cooled water returns to the RDHX to continue absorbing heat.

   If ambient air is too warm, supplementary chillers can maintain water temperature.

3. Benefits

• High energy efficiency: Free cooling reduces or eliminates the need for chillers in cool months.

• Localized heat removal: RDHX cools the servers directly, improving performance and reliability.

• Reduced PUE (Power Usage Effectiveness): Lower overall energy consumption for cooling.

• Scalability: Easy to expand as more racks are added.

In short:
This system combines direct rack cooling (RDHX) with ambient-air-based water cooling (Dry Cooler) to efficiently remove heat from high-density server racks while minimizing energy consumption.