In sizes 5 to 40 ton, the VPAX series is specifically designed to provide a safe, clean indoor environment for RIE and similar buildings containing computers and other sensitive electronics.  As specified, the system provides either:

• Environmental protection with over-pressurization inside the building to prevent infiltration of corrosive gasses, or,
• Class I, Division 2 hazardous location positive pressurization of 0.1” WC (min.) to prevent infiltration of hazardous and corrosive gasses and reduce the classification inside the building to an ordinary (non-hazardous) location.

Featuring two air conditioning units for full redundancy, the VPAX incorporates cooling, heating, and dual pressurization with gas-phase air filtration into a single system. The VPAX is designed to allow for easy installation and maintenance. The complete assembly is designed for installation on the exterior of the building.  Only the control section with supply and return air openings penetrates the building making for a minimal wall cutout.  Structural support underneath the VPAX is required to be provided by the customer.

To protect sensitive equipment, make-up air for purge and pressurization is scrubbed as it passes through particulate pre-filters, carbon and/or potassium permanganate media cells, and final filters to remove corrosive gasses and other pollutants.   A portion of the return air is recirculated through the filtration section of the system for continual cleaning of the indoor atmosphere.   Pressurization air passes through the cooling and heating sections and is preconditioned before entering the room.

In compliance with NFPA 496, each pressurization blower provides a purge of 60 feet per minute through open doors to maintain the non-hazardous classification of the indoor space and prevent the entrance of hazardous and corrosive gasses.

VPAX features include:

• Single-package construction with fork-lift base and completely pre-wired controls for ease of installation,
• Two independent cooling and heating systems,
• **Separate thermostats and humidistats, and a 7-day timer to allow equal run time for each system,
• Class I, Division 2 design in the condenser (outdoor) and pressurization sections when required,
• Dual pressurization and dual purge in compliance with NFPA 496,
• Gas-phase air filtration with easy access for removal and replacement, and with either:
  • Single bed bulk fill chemical media, or,
  • Chemical media cells,
• Alarm for loss of room pressure,
• Corrosion protection coatings on coils, compressors, copper tubing, and other exposed  components,
• Urethane coated galvanized steel cabinetry (stainless steel optional),
• Fresh air stack with rain cap,

** Optional PLC control with HMI interface (touch screen). ** Optional redundant PLC control with dual HMI interface (touch screens).  

Fresh air stacks can be furnished in a guy-wire or free-standing style and includes a rain cap with bird screen.  Free-standing stacks can be furnished in either a welded pipe design or in a lighter weight, heavy gauge spiral pipe design.  Our free-standing stacks are made in 10 foot long (max.) sections and with heavy, seal-welded flanges at both ends.  The free-standing stacks are P.E. Certified for:

•  130 MPH winds - Free-standing spiral pipe design, up to 30 feet tall.
•  150 MPH winds - Free-standing welded pipe design, up to 30 feet tall.

Free-standing stacks must be properly secured at the base with anchor bolts in a concrete foundation or seal-welded to a structural steel support.

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