DVN 5000
Environmental Guidelines
32
24-10520-22 Rev. –
This document contains confidential and proprietary information of Johnson Controls, Inc.
© 2009 Johnson Controls, Inc.
Heat Exchangers and Air Conditioning Units
In harsh environments, such as dirty factory floors, filters quickly become clogged
and heat inside the rack builds rapidly. In these applications, gasketed and sealed
racks rated by the National Electrical Manufacturers Association (NEMA®) should
be installed.
Heat exchangers and air conditioning units (mostly installed in NEMA-rated racks)
do not allow the ambient dirty air to mix with the enclosure interior air, which helps
the interior rack air stay clean.
Figure 21: Correct use of Simplified Heat Exchangers and Air Conditioners
These devices (either water-coil or refrigerant-compressed) are also the only way to
make the temperature inside the rack cooler than the ambient air. However, avoid
condensation when cooling the rack with an air conditioning unit. To prevent
condensation, keep the temperature above the dew point.