White Paper - Row-based cooling with the LCP Passive
Rittal
Rittal's fanless LCP Passive rear-door heat exchanger relies on the servers' own fans, and nothing inside it is powered. The paper therefore concentrates on the room conditions that must hold for it to work.
On this page
Overview
The paper begins by citing infrastructure as about half of data-centre electricity, with cooling the largest share at 37 % of the total in the cited breakdown. The LCP Passive has no fans, controller or power connection and provides useful cooling of up to 20 kW per rack. The door opens 120 degrees despite the water connection and mounts in place of a standard rear door, making it suitable for retrofit.
The mechanism is that server fans must overcome the coil's air-side pressure loss, and no opposing airflow may exist at the door outlet. For that reason rows cannot alternate hot and cold aisles: all rows blow in one direction, forming a single room air loop. This condition is the fundamental difference from a conventional CRAC layout.
Inside the rack the arrangement changes too. Internal foam and baffle partitioning must be repositioned so exhaust air reaches the door without recirculating. The paper contrasts the passive door with the powered LCP Rack and Inline units. Being a manufacturer paper, it presents the passive door as the preferred solution and does not treat failure cases in detail.
Key points
- Infrastructure is about half of data-centre electricity; cooling is the largest share at 37 % of the total in the cited breakdown.
- LCP Passive has no fans, controller or power connection and gives useful cooling up to 20 kW per rack.
- The door opens 120 degrees and replaces a standard rear door, so it suits retrofit.
- Server fans must overcome the coil's air-side pressure loss; no opposing airflow may exist at the door outlet.
- Rows must not alternate hot/cold aisles; all blow in one direction.
- Internal foam/baffles must be repositioned so exhaust reaches the door without recirculating.
Using it in design
- Catalogue rear-door coolers with a passive/active flag, kW capacity and air-side pressure drop.
- If passive rear doors are selected, require uniform row orientation and warn about facing rows with opposing exhaust.
- Check server fan static-pressure capability where known, and include blanking and partitioning in the BOM.
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Who should read it
Cooling designers planning a retrofit or new row layout with passive rear-door heat exchangers.
Publication details
- Authors
- Rittal
- Publisher
- Rittal
- Year
- 2012
- Document number
- 3_1139
- Document language
- English
- Source type
- Manufacturer
- Access
- Free to read
- Licence
- Copyright retained; citation only — the publisher’s terms apply to the original document
Citation
Rittal (2012). White Paper - Row-based cooling with the LCP Passive. Rittal. 3_1139. https://www.rittal.com/imf/none/3_1139/Rittal_3311900_White_paper_3_1139
Events on this subject
- ISK-SODEX Istanbul 2027
- SC26 – International Conference for High Performance Computing, Networking, Storage and Analysis
- ASHRAE Winter Conference
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