Finned tube heat exchanger RDHX series

air/wateractiverack-mount

Overview
The EXTRCOOL Rear Door Heat Exchanger (RDHX) is a rack-mounted, door-integrated liquid cooling solution purpose-built for high-density AI and HPC server racks. Designed to pair with NVIDIA GB200/GB300 and next-generation GPU servers, this unit replaces standard rack rear doors with an integrated heat exchanger, capturing hot exhaust air directly at the source and rejecting heat via chilled water loops. It eliminates hot spots, reduces facility cooling loads, and supports rack power densities up to 50kW and beyond.

Core Technical Advantages

• Door-integrated, zero floor space design: mounts directly to the rear of standard server racks, requiring no additional floor footprint and simplifying deployment in new and retrofitted data centers.
• Direct hot air capture: captures server exhaust at the rack rear, eliminating hot air recirculation and reducing the need for raised-floor air conditioning.
• High-capacity heat rejection: efficiently transfers waste heat from exhaust air to chilled water loops, supporting high-density AI and HPC workloads with minimal facility cooling overhead.
• Flexible deployment: compatible with both new liquid-cooling data centers and retrofits using existing chilled-water infrastructure for phased adoption.
• Low-noise, energy-efficient operation: reduces reliance on high-speed rack fans and raised-floor cooling, lowering overall PUE and noise levels.

Product Specifications
Brand: EXTRCOOL
Model Series: RDHX-Series Rear Door Heat Exchanger
Cooling Type: Air-to-liquid heat rejection
Product Category: Rack-mounted rear door heat exchanger
Installation Type: Rear door installation (supports top/bottom water inlet methods)
Compatible Systems: Standard 19-inch server racks, chilled water networks
Place of Origin: Guangdong, China

Model Numbers and Rated Cooling Capacity:
EXT-30RDHX - 30 kW
EXT-60RDHX - 60 kW
EXT-90RDHX - 90 kW
EXT-120RDHX - 120 kW

Coolant: PG25 (all models)
Operating environment T&H: -10°C ~ 55°C / RH 5% ~ 90%
Storage environment T&H: -45°C ~ 70°C / RH 5% ~ 93%
Air & liquid temperature gap: 15°C / 10°C
Air temperature (in/out): 42°C / 27°C
Secondary side liquid temperature (out/in): 24°C / 34°C

Air flow rate by model:
EXT-30RDHX - 6000 m³/h
EXT-60RDHX - 12000 m³/h
EXT-90RDHX - 20000 m³/h
EXT-120RDHX - 25000 m³/h

Liquid flow rate by model:
EXT-30RDHX - 50 LPM
EXT-60RDHX - 90 LPM
EXT-90RDHX - 130 LPM
EXT-120RDHX - 180 LPM

Power Supply: 208–277 VAC 50/60 Hz
Dual power ATS: Yes (all models)
Control type: PID control regulating fan speed based on temperature sensors (inlet/outlet air and supply/return water)
Leak detection: Yes (all models)
Redundant fan automatic switchover: N+1 (all models)
Power consumption (typical by model): <0.7 kW (30 kW), <1.2 kW (60 kW), <2.2 kW (90 kW), <2.6 kW (120 kW)
Communication: Modbus RTU & TCP/IP
Design pressure: >10 Bar (all models)
Approx. weight by model:
EXT-30RDHX - 85 kg
EXT-60RDHX - 110 kg
EXT-90RDHX - 155 kg
EXT-120RDHX - 195 kg
Protection level: IP55 (all models)
Dimensions (W x D x H) mm by model:
EXT-30RDHX / EXT-60RDHX - 600 x 210 x 2000/2200 mm
EXT-90RDHX / EXT-120RDHX - 800 x 240 x 2200/2200 mm

Ideal Application Scenarios

• High-density AI data centers: supports 30–50 kW rack loads for GB200/GB300 GPU clusters.
• HPC & supercomputing clusters: eliminates hot spots in high-performance computing environments.
• Traditional data center retrofit: enables phased liquid cooling upgrades without major infrastructure changes.
• Colocation & enterprise data centers: reduces facility cooling loads and supports mixed-density rack deployments.
• Edge & compact data centers: ideal for space-constrained facilities with limited raised-floor cooling capacity.

Why Choose EXTRCOOL Rear Door Heat Exchanger?
The RDHX provides a non-intrusive, space-efficient solution to increase rack power density without major facility overhauls. By combining direct hot-air capture, efficient heat rejection, and flexible deployment options, EXTRCOOL RDHX-Series supports stable, energy-efficient operation for demanding AI and HPC workloads year-round.

Frequently Asked Questions
Q1. What is a rear door heat exchanger used for?
A rear door heat exchanger (RDHX) is a rack-mounted liquid-cooling solution that replaces a server rack’s rear door, captures hot exhaust air, and transfers heat to a chilled water loop to eliminate hot spots and support higher rack power densities.

Q2. What are the benefits of an RDHX over other liquid-cooling solutions?
RDHX units require no additional floor space, integrate directly into standard racks, and enable phased liquid-cooling adoption. They reduce hot-air recirculation and lower reliance on facility air conditioning.

Q3. Is the unit compatible with standard server racks?
Yes. The RDHX is designed for standard 19-inch server racks and supports common chilled-water pressures and temperatures.

Technical specifications

• Brand: EXTRCOOL
• Model / Series: RDHX-Series Rear Door Heat Exchanger
• Available models: EXT-30RDHX, EXT-60RDHX, EXT-90RDHX, EXT-120RDHX
• Rated capacities: 30 kW, 60 kW, 90 kW, 120 kW
• Cooling type: Air-to-liquid heat rejection
• Air flow: 6,000–25,000 m³/h depending on model
• Liquid flow: 50–180 LPM depending on model
• Power: 208–277 VAC 50/60 Hz; dual power ATS: Yes
• Protection: IP55
• Design pressure: >10 Bar
• Communication: Modbus RTU & TCP/IP
• Approx. weight: 85–195 kg depending on model
• Dimensions (W x D x H) mm: 600 x 210 x 2000/2200 or 800 x 240 x 2200 depending on model