Specific Systems: Severe Duty and Explosion Proof HVAC

Engineered for performance and durability in the world’s most difficult environments.

Specific Systems® InPac™ Series wall-mounted industrial severe duty and explosion proof HVAC units are engineered and proven to provide safe air conditioning and stand up to the rigors and harsh conditions of corrosive and hazardous environments, including those found in refineries, water/wastewater treatment plants, and on oil drilling rigs and offshore processing plants.

  • Available for use in hazardous Class I, Division 1, Groups C, & D locations, as well as Class I, Division 2, Groups B, C, & D
  • Standard through the wall air conditioning configuration
  • Also configurable in Wall MountPad MountRoof Mount, or Split configurations, using the same components for reduced lifetime costs
  • Built to demanding industrial specifications
  • Innovative two-stage dual refrigeration circuit provides 50% redundancy on units over 3 tons
  • Available corrosion resistant coatings and many other options
  • CSA certification, UL Listed panels, with ATEX and IECEX certification available.






InPac™ units include as standard what many others consider modifications or special features. Beginning with 16-gauge powder coated galvanized steel cabinets with stainless steel fasteners and drain pans, InPacs are industrial duty by design.

Industrial Cabinet Construction

  • 16-gauge or heavier 316L stainless steel is standard
  • Optional 304 stainless steel, hot-dipped galvanized steel, or aluminum
  • Galvanized steel and aluminum are powdercoated in-house to a thickness of four mils, with several colors available

Redundancy: Built-in

Dual Fans

Providing conditioned air into a space is the main purpose of an ECU, and InPac™ units are built to deliver.

  • Units from two tons (24,000 BTUH) to 50 tons (600,000 BTUH) utilize dual spark-proof evaporator blower assemblies
  • Two forward-curved blowers run concurrently on a double-shafted industrial grade motor
  • Two additional blowers can be optioned to serve as redundant backups
  • Main and aux fans are used to purge and pressurize the area in the event of a pressure loss, if required
  • Spark-proof axial condenser fans are standard on InPac units

Evaporator and Condenser Coils

  • Standard coils are constructed from heavy-weight rifled copper tubes mechanically bonded to aluminum fins
  • Standard coils can be coated with our SpecificCoat™ two-stage corrosion resistant coating, designed to give you optimal protection with minimal loss of heat transfer
  • All InPac™ evaporator and condenser coils interlace two completely separate refrigeration circuits
  • This allows the InPac™ unit footprint to remain as small as possible while still offering the redundancy and efficiency of four separate coils.
  • Condenser coils are designed at 8 FPI to reduce clogging in industrial environments
  • Evaporator coils are designed at 11-13 FPI for efficiency
  • Highly corrosion resistant copper fin/copper tube coils are available as an option
  • Several corrosion resistant coatings are also available as options
  • Freezestats are also standard on all InPac™ systems


  • Two hermetically-sealed scroll compressors
  • Crankcase heaters are provided as a standard feature to further extend the life of compressors

Control Designed for Ease of Use

Control Systems

  • UL 508A Listed and labeled control panels are located in the unit chassis
  • Remotely mounted panels are available
  • Utilize the most reliable industrial components and modern technology with all wires numbered and labeled for easy recognition during service.
  • Basic features of standard InPac™ HVAC control panels include two-stage control on both heating and cooling, automatic switching, and manual override switches for both stages, if desired.

Temperature Control

  • Close-tolerance temperature control is provided by a dual-stage digital thermostat
  • Remote mounting is available
  • Remote temperature and interface control panels capable of controlling multiple individual units from a single location can also be provided

Power Control

Fans, compressors, and other components in standard InPac™ units are automatically shut down by numerous safety devices, depending on any of several overload conditions. Standard fault interrupts on InPac™ units include

  • High and low refrigerant pressure on both circuits
  • Evaporator coil freeze
  • Compressor high current/temp overload
  • High temperature in the heating coil
  • Fan motor overloads
  • Compressor restart delay.

Each of these faults can be wired to trigger a local and remote alarm if desired.


  • Standard InPac return air filter is a 1″ aluminum frame washable flexible polyurethane foam media (UL Class 2).
  • Standard InPac outside air filter is a 2″ Farr 30/30, a MERV-8 pleated panel filter that meets most industrial and commercial filtration requirements.
  • Additional chemical filtration and high efficiency filtration, including HEPA, can be provided as shown in the optional equipment list.

Please check with your sales representative for full details on available filtration options.


  • System failure alarm Form C contacts for each of the two refrigeration circuits are provided on all units.
  • Units ordered with the optional NFPA 496 purge & pressurization package also include purge system failure, instantaneous and sustained building pressure loss alarms as standard features.
  • All alarms offer one or more Form C dry contacts for interface to remote monitoring systems for notification of an alarm event.
  • A multitude of other alarms, as well as unit mounted visual and audible indicators are available as options.

Need more information?  Please contact Connor Doyle today!