Stability Chambers for a Multitude of Applications.

Product Selection

Model Capacity Electrical
same as 3911-11This product has more than one valid catalog number.
11 cu. ft., 311.5L 208/220V 60Hz
3913 11 cu. ft., 311.5L 220/240V 50/60Hz
3920 29 cu. ft., 821.2L 120V 60Hz
3940 29 cu. ft., 821.2L 208/220V 60Hz
3949 29 cu. ft., 821.2L 220/240V 50/60Hz


  • Perform a variety of applications with Thermo Scientific Forma Environmental Chambers, which can be configured for a variety of purposes and are available in multiple capacities.
  • With a wide range of accessories and years of experience in constructing cabinets, we can construct units to match your most stringent applications.

Broad Range of Features and Controls

  • Wide temperature range of 0° to 60°C that enhances the flexibility of the unit.
  • Relative humidity control via steam generator from above ambient to 95% at 37°C (not available w/Cat. No. 3920).
  • Sophisticated digital controls.
  • Programmable ramp and soak cycles for temperature and RH†.
  • Durable cabinets with true laminar airflow through side plenums for extremely tight uniformity.
  • Phenolic-coated evaporator for use in applications that create corrosive byproducts.
  • Manual control of defrost and refrigeration cycles.
  • Visible/audible safety alarms alert to over- and undertemperature conditions, deviation of humidity from set parameters (except Model 3920).

Durable Construction

  • Cold-rolled steel, powder-coated cabinet.
  • 2" (5.1cm) thick, CFC-free, foamed-in-place polyurethane insulation.
  • Stainless-steel interior with solid stainless-steel adjustable shelves.
  • Directed horizontal airflow system for excellent uniformity.
  • Locking swivel casters for easy mobility during installation and cleaning.
  • Leveling feet for stability and added safety in the lab.

Broad Range of Options

  • Interior lighting for Models 3920, 3940 and 3949 (Optional).
  • Reinforced shelving and flooring for heavy loads.
  • Heatless dryer for lower humidity levels.
  • Access ports for probes, sensors.
  • Interior convenience receptacles.
  • CO2 (IR sensor).
  • 6" and 12" temperature chart recorder.
  • Other custom options available.

Compatible with

  • Recorders (197075, 198036, 198039, 198042, 201144, 201145, 201146, 201147).
  • Reach-In/Environmental Chamber Solid Stainless-steel Shelf (224139).
  • Reach-In/Environmental Chamber Perforated Stainless-steel Shelf (224155).
  • Reinforced Stainless-steel Shelf (224161).
  • Fixed Reinforced Stainless-steel Shelf for two shakers (1900005).
  • Stainless-steel Door Glass Cover, factory installed (190591).

Recommended for

  • Ideal for growth, stability and shelf-life testing applications.

Ordering Information

  • † Humidity controller available on 3940/3949, 3911/3913 only.


Thermo Scientific Forma Environmental Chambers Product Brochure