1. Door Heat Exchanger: Specification
John Fernandes
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2. Potential applications: Naming convention
Traditional
(air-to-liquid)
Hybrid (air-to-liquid
& liquid-to-liquid)
Air-assisted
(liquid-to-air)

3. Physical specifications

4. Physical specifications
Hinged solution for ease-of-access: Fans, power-bus bar, manifolds, etc.
Weight limitations
Assembled and primed rack: ≤ 3086lbs (1400kg)
Door HX only: 220lbs (100kg) preferred; 330lbs (150kg) maximum
Minimum aisle width of 4ft (1220mm)
Permit opening of door by at least 90° without interfering with adjacent racks

5. Physical specifications

6. Physical interfaces Facility coolant Electrical (active variant)
Connections should be permitted from both top and/or bottom sides
Accommodate different interface types for flexibility on-site; QC-type?
Electrical (active variant)
Supply options: 110 or 230VAC (50/60Hz)
AC plug-in connector: C14 or C20
DC supply from open rack power-bus bar (11 to 54VDC)?
Fuse specification? Preferred location?
Communication
Port type and protocol? Preferred location?

7. Facility air-side conditions
Cold-aisle Temperature
18°C ~ 35°C (65°F ~ 85°F)
Temperature Ramp Rate
5°C/15min
Cold-aisle Pressurization
0.005” H2O (1.24Pa)
Relative Humidity
10% ~ 90%
Altitude
≤ 2000m (6600ft)
Temperature Difference *
≥ 12.2°C (22°F)
* or dependent on IT gear being supported; 12.2°C may serve as a reference value to define performance metrics under 100% neutralization of heat load

8. Facility coolant requirements
Operating pressure: Typical range? worst-case?
Supply temperature: ≥12°C (non-condensing); typical range?
Coolant DT across door: Typical range? Target for efficient operation?
Supported coolant types: Water, water + glycol, dielectric
Pressure drop requirements?

9. Performance / Metrology
Cooling or heat rejection capacity should be defined in kilowatts (kW)
Based on: Air and coolant flow rates, inlet temperatures to HX and operation at sea- level
Performance curves (or tables) should be provided for both normal and fan failure operation
Active variant
N+1 rotor/fan redundancy is a must
Total power consumption should be ≤ 2% of rated cooling capacity (not including fan failure)
De-rating factors for cooling capacity based on coolant selection (with respect to water) and altitude (with respect to sea-level)
Air- and coolant-side pressure drop curves should be provided

10. Monitoring & Control
Which of the following could be classified as required, recommended or optional?
Monitoring
Door inlet and outlet temperatures, differential pressures (air and coolant)
Fan duty cycle or speeds
Modulating coolant control valve (position), coolant flow rate
Absorbed power, total power consumption
Alarms
Fan high/low speed, fan failure
Sensor failure, communication failure
Leak detection
Control
Air outlet temperature, water outlet temperature
Differential water temperature, differential air temperature
Reporting should employ the REDFISH standard

11. Serviceability Ease of replacing Door HX
Draining, un-mounting, installation and priming
Access to physical interfaces (coolant connections, power supply and communication cables)
Containment and discharge of expelled coolant in the event of a leak?
Discharge from condensation pan at the bottom of Door HX assembly?
Ease of replacing fan modules
Ease of replacing sensors or other accessible parts

12. Quality & Testing Testing of HX after assembly Quality
Pressure rating: Reference condition, factor-of-safety?
Leak testing
Checking physical interfaces?
Quality
Soldered joints only?
Sealing on adapter frame and/or HX to prevent leakage of server exhaust or entrainment of facility air?
Any other requirements that should be standard?

13. Regulations, Compliance, etc.
What are standard requirements?
Labels and markings?
Vibration & shock