SSTWB Workroom Units


Low velocity air units for processing rooms. These models feature axial fans and many end user oriented features.


  • One to Five Fan Models
  • Hinged Access Panels
  • Sloped Top Panels
  • Dual Sloped Full Coverage Drain Pans
  • Rated in Accordance with AHRI Standard 420



Design Features

Maintenance Features

Optional Equipment

Unit Specification

SSTWB Workroom Units - Design Features


The STW evaporators are equipped with owner-oriented benefits that improve the operation of processing rooms. The ease of maintenance and improved accessibility reduces downtime required for clean-up.

SSTWB Workroom Units - Maintenance Features

SSTDB Low Profile Coolers - Optional Equipment

STW Series Evaporators

Low Velocity Workroom Units

Innovative Design Features with Superior Quality, Performance and Dependability


Low velocity air units for processing rooms. Units feature stainless construction with hinged panels for easy access. STW Evaporators are designed to provide working comfort in high occupancy rooms. STW Evaporators are offered with Stainless Steel tubes and aluminum fins.

Design Features


Heavy Duty Coil with Stainless Steel Tube with Aluminum Fin. Standard Catalog Models with Three, Four or Six Fins per Inch, Variable Fin Spacing Available as an option.


Coil Built in Accordance with ASME/ANSI B31.5. Charged With Nitrogen Prior to Shipment to Prevent Entry of Moisture and Contamination. Pressure Tested Under Water to 400 PSIG.


Type 304 Stainless Steel Casing to Provide Maximum Corrosion Protection for Critical Process Environments. Heavy Gauge G235 Galvanized Steel Casing Available at a Reduced Cost.


Rugged Air Deflector Design Provides 360o Air Discharge Pattern while Maintaining Low Air Velocities.


Hinged Access Panels with Conveniently Located Fasteners Allow Cleaning and Inspection of Coil and Fan Motors and Reduces Maintenance Time.


Totally Enclosed Air Over (TEAO) Fan Motors with Internal Thermal Overload Protection, Sealed Bearings and Low Temperature Grease for Reduced Maintenance and Longer Life. Two Speed/Two Winding Motors Available as an Option. Fan Motors may be Wired to Common NEMA 4X Junction Box and Supplied With Disconnects and/or Starters.


High Efficiency Sheet Metal Fan Blades for Low Noise to Improve Worker Comfort and Safety. Optional Cast Aluminum Fan Blades are Available for Low Temperature Applications.


Heavy Duty PVC Coated Fan Screens conform to all OSHA Requirements.


Individually Compartmentalized Fan Sections to Prevent Air Bypass and Allow Fan Cycling.


Totally Enclosed Air Over (TEAO) Fan Motors with Sealed Bearings and Low Temperature Grease for Reduced Maintenance and Longer Life. Fan Motors on Catalog Models up to 1-1/2 HP are Equipped with Automatic Thermal Overload Protection. Individually Wired Fan Motors to NEMA 4 Junction Boxes. Motors may be Supplied with Disconnects and/or Starters.


Sloped Top Panels to Prevent Moisture from Accumulating on the Top of the Unit. Water from the Top of the Unit will Drain into the Over-sized,


Full Coverage Drain Pan, Improving the Cleanliness of the Unit and Preventing the Possibility of Product Contamination. Full Coverage, Fully Accessible Drain Pans Provide Full Coverage of the Entire Casing Section and Coil Connections. This Design Ensures that All Moisture from the Evaporator Collects in the Drain Pan while Preventing any Droplets from Falling into the Refrigerated Space. In Addition, the Drain Pans are Fully Accessible wth the Wet Coil Baffles Installed in the Middle of the Coil to Prevent Air Bypass and Allow for Drain Pan Access from Both Side of the Coil. Hygienic Drain Pans are Sloped in Two Directions to Prevent Water from Pooling in the Pan. The Drain Pans are Custom Engineered and Equipped with Swaged Bottom Outlets to Ensure Complete Drainage.


Hot Dip Galvanized Structural Steel Legs are Designed for Greater Structural Rigidity and Easier Installation. STM Models Ship with Sheet Metal Channels that Allow the Unit to be Easily Handled with a Forklift. Once the Unit is Installed, the Shipping Supports are Easily Removed.


Superior Defrost Technology with Optional Water Defrost, Electric Defrost and Hot Gas Defrost Arrangements Available. Optional Hot Gas Defrost Pan Includes Closely-Spaced, Heavy Wall Pan Coil. Hot Gas Pan Coil may be Piped either in Parallel or in Series with Cooling Coil. Factory Mounted Piping with Pan-to-Coil Check Valve.

Innovative New Technology


Coil Design Developed Through Extensive Testing at EVAPCO's Advanced Research and Development Laboratory and Industry Experience.


  •     Thermal Performance Guaranteed.
  •     Optimized Coil Circuiting for Increased Performance.
  •     Clean Tube and Fin Pattern Ideal for Food Freezing Applications.


Proven Performance Resulting In:


  •     Lower Horsepower
  •     Greater Capacity
  •     Hygienic Design

Clark Johnson Company, Inc.       2016