These units are designed to provide cooling, heating, and pressurization in one assembly.  Although separate pressurization and air conditioning units are still viable alternatives, they are being used less and less as more efficient combination units are sought out for new installations.  Combining the two systems into one unit has distinct advantages.

These advantages include: 

- Dehumidifying and pre-conditioning the pressurization air before it enters   

   the room prevents condensation and wide temperature swings,

- The unit is completely pre-wired,

- Less wall space is required than with a separate air conditioner and

   pressurizer, and,

- Installation time is faster.  

The WCPX (explosion proof air conditioner) and WHPX (explosion proof heat pump) series are CSA (C/US) certified for hazardous locations in sizes 1-1½ through 6 tons, and are available up to 20 tons.   In addition to the apropriate Class I, Division markings, units may additionally be marked with the US and Canadian Class I, Zone system upon request (example: Class I, Zone 2, group IIB+H2).

• The WCPX-G and WHPX-G series is specifically designed for switchgear buildings, MCC rooms, RIE buildings, control rooms, and similar buildings whose interiors will be declassified to an ordinary (non-hazardous) location by the pressurization and purge features of the unit.

• The WCPX-H and WHPX-H series is specifically designed for analyzer shelters and similar enclosures containing a source of flammable gas, vapor, or liquid and having limited, or no release of these materials under normal conditions (for more information, refer to NFPA 496, chapter 9).

IEC Zone 2 - The WCPF-G and WCPF-H series are similar to the WCPX except that they are designed for use in IEC Zone 2 hazardous areas. Although they do not bear the CE mark or A.T.E.X. certification as required for installation in the European Union, they are intended for use in other countries that prefer the IEC methods of protection.  The WCPF-G and WCPF-H series are certified to conform to Zone 2 requirements by Marc Climatic Controls and all applicable Certificates of Conformity will be provided for components.  These air conditioners are not for installation in North America.    

The VPAX series is specifically designed to provide a safe, clean indoor environment for RIE and similar buildings containing computers and other sensitive electronics. The system provides 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 twin removable heating and cooling 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. Structural support underneath the VPAX is required to be provided by the customer. Only the control section with supply and return air openings penetrates the building making for a minimal wall cutout.

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 from the enclosed space is passed 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 one or two open doors to maintain the nonhazardous classification of the indoor space and prevent the entrance of hazardous and corrosive gasses.

Standard VPAX features include:

• Single-package construction with fork-lift base and completely pre-wired

    controls for ease of installation,

• Class I, Division 2 design in the condenser (outdoor) and pressurization sections,

• Two independent cooling and heating systems, separate thermostats and

    humidistats, and a 7-day timer to allow equal run time for each system,

• Dual pressurization and dual purge in compliance with NFPA 496,

• Gas-phase air filtration with chemical media cells and easy access for 

    removal and replacement,

• 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.

The DCPX-CF series is a single packaged, fully redundant cooling, heating, pressurizing and purge system while incorporating a deep bed scrubber for gas-phase air filtration into its design.  The unit includes particulate pre-filters, a carbon or potassium permanganate media bed, re-filters, and final HEPA filters to remove corrosive gasses and other pollutants.  

The system also provides positive pressurization to prevent infiltration ofhazardous and corrosive gasses and reduce the classification inside the building to an ordinary (non-hazardous) location.      

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, 27 foot tall.
•  150 MPH winds - Free-standing welded pipe design, 27 foot 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.

Packaged units and split systems are available in much greater cooling capacities. Systems are designed for Class I, Division 2 hazardous (classified) locations and to provide Type Z pressurization. Chemical filtration and redundant blowers can also be incorporated into the design.  All systems are capable of a black start.

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