DVN 5000
Environmental Guidelines
36
24-10520-22 Rev. –
This document contains confidential and proprietary information of Johnson Controls, Inc.
© 2009 Johnson Controls, Inc.
The downside to using a totally perforated cabinet and cold air-cooling in a data
center is uneven cooling and short-circuiting of airflow. If the air is too cold,
condensation can occur, and energy costs for the facility will be high.
Older data centers were mostly designed for equipment racks with less heat output
per rack footprint, so pay special attention to any equipment changes or additions.
Figure 24: Optimum Arrangement of High Heat Density Racks
The optimum layout for high heat density racks is an arrangement in rows of two to
produce both hot and cold aisles (see Figure 24). The
front
of the racks face each
other in the cold aisle, with air grating down the center for cold air supply. The
rear
of the racks face each other in the hot aisles, with return grills overhead for optimum
utilization of the air conditioning system.
How to Calculate Ventilation Required to Provide an Interior
Rack Temperature of 85°F (29ºC)
The nomograph on page 38 shows the minimum ventilation (active or passive)
required to provide an interior rack temperature of 85ºF (29ºC).
To calculate total waste heat (column B):
1. Obtain total waste heat output by combining the published waste heat
BTU/Hr. of all DVNs in the rack.
DVN 5000 Rackmount Series BTU/Hr.:
Typical: 655; Maximum: 706
2. Add up total measured amperage draw from all other equipment and
multiply by 400 (total amperage x 400 = total BTU/Hr. @117V).