Thermo Forma 3940 Refrigerated Environmental Chamber

Brand : Thermo

Product Code : SKU 3175GG INC

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Thermo Forma 3940 Refrigerated Environmental Chamber (Solid Door)

Many laboratory applications require more than a standard incubator. Stability testing, pharmaceutical storage, environmental simulation, and long-term product validation demand precise control of temperature and humidity over weeks or even months. The Thermo Forma 3940 Refrigerated Environmental Chamber with Solid Door was developed specifically for these demanding applications, providing exceptional environmental stability while protecting sensitive samples from external temperature fluctuations and ambient light exposure.

Featuring a 29 cubic foot (approximately 821-liter) chamber, the Thermo Forma 3940 combines refrigerated cooling, programmable heating, humidity control, and directed airflow technology to create highly uniform environmental conditions throughout the cabinet. Unlike glass-door environmental chambers that prioritize sample visibility, the insulated solid-door configuration maximizes thermal efficiency, minimizes heat gain during operation, and provides additional protection for light-sensitive materials. Purchasing a refurbished Thermo Forma 3940 from American Instrument Exchange allows laboratories to obtain premium environmental testing capabilities while significantly reducing capital equipment costs.

Key Features

29 cu. ft. (approximately 821 L) chamber capacity
Solid insulated outer door
Refrigerated heating and cooling system
Temperature range from 0°C to 60°C
Humidity control from ambient to 95% RH
Directed airflow plenum system
Microprocessor PID controls
Temperature resolution of 0.1°C
Temperature uniformity of ±0.3°C
Large stainless steel chamber
Adjustable shelving system
Audible and visual alarms
Designed for continuous operation
90-day warranty from American Instrument Exchange

Designed for Stability Testing and Controlled Environmental Research

Environmental chambers are often expected to operate continuously for months while maintaining tightly controlled conditions. Even minor variations in temperature or humidity can influence pharmaceutical stability studies, packaging validation, biological storage, and accelerated aging research.

The Thermo Forma 3940 was engineered to provide highly reproducible environmental conditions across a large-capacity chamber. Its refrigeration system allows operation both below and above ambient temperatures, while integrated humidity control supports applications requiring controlled moisture exposure. These capabilities make the chamber an excellent solution for laboratories conducting regulated stability studies, environmental simulation, and long-duration biological research.

The solid insulated door further enhances chamber performance by reducing thermal losses and limiting exposure to ambient laboratory lighting. For applications involving photosensitive pharmaceutical products, packaging materials, or biological samples, minimizing unnecessary light exposure can improve experimental consistency while reducing the frequency of environmental disturbances caused by routine inspections.

Many laboratories incorporate environmental chambers alongside laboratory refrigerators, ultra-low temperature freezers, biosafety cabinets, analytical balances, and stability monitoring systems to support complete pharmaceutical development and quality assurance workflows.

Common Applications

The Thermo Forma 3940 is commonly used for:

Pharmaceutical stability studies
ICH stability testing
Shelf-life evaluation
Drug product storage
Packaging validation
Accelerated aging studies
Controlled humidity testing
Biological sample storage
Seed germination research
Entomology research
Botanical studies
Medical device testing
Food product stability studies
Industrial quality control

Its broad operating range makes the chamber suitable for both refrigerated storage applications and elevated-temperature environmental testing.

Ideal Laboratory Environments

The Thermo Forma 3940 is widely used in pharmaceutical manufacturers, biotechnology companies, quality assurance laboratories, contract testing organizations, university research facilities, government laboratories, and industrial research centers.

Because of its large interior volume and excellent environmental uniformity, the chamber is particularly valuable for laboratories processing high sample volumes or conducting multiple stability protocols simultaneously. The solid-door configuration is especially attractive for facilities storing light-sensitive products or operating in laboratories where minimizing thermal fluctuations is a priority.

Temperature Recovery and Environmental Stability

Maintaining precise environmental conditions across a chamber approaching 30 cubic feet requires sophisticated airflow management and accurate electronic controls. The Thermo Forma 3940 utilizes a directed airflow plenum system that distributes conditioned air evenly throughout the cabinet, minimizing temperature gradients between shelves while promoting rapid recovery following door openings. Unlike conventional top-down airflow systems, the directed airflow design circulates conditioned air through both positive and negative pressure plenums to improve chamber uniformity under varying sample loads.

Operating from 0°C to 60°C, the chamber provides precise temperature control with 0.1°C resolution, ±0.1°C accuracy, and ±0.3°C uniformity between 25°C and 37°C. Integrated humidity control allows operation from ambient humidity levels up to approximately 95% RH, supporting a broad range of environmental simulation and stability testing protocols.

Environmental Control and Sample Protection

The Thermo Forma 3940 is designed not only to maintain stable environmental conditions but also to protect valuable samples throughout extended testing periods.

The insulated solid door reduces heat transfer between the chamber and the surrounding laboratory environment, improving temperature stability while lowering refrigeration demand. Eliminating a viewing window also limits exposure to ambient light, making the chamber well suited for pharmaceutical products, biological materials, and other light-sensitive samples that require controlled storage conditions. Combined with programmable temperature and humidity controls, the solid-door configuration provides a stable environment for long-term studies where consistency is essential.

Sample Storage Recommendations

The Thermo Forma 3940 offers approximately 29 cubic feet (821 liters) of conditioned chamber space, making it well suited for laboratories performing large stability studies, long-term environmental testing, or high-volume sample storage. The spacious stainless steel interior accommodates adjustable shelving configurations for pharmaceutical products, medical devices, packaged materials, laboratory reagents, biological specimens, environmental test samples, and research materials requiring tightly controlled temperature and humidity conditions.

Because of its large capacity, many laboratories organize the chamber by study, batch number, time point, or project to simplify sample retrieval while minimizing unnecessary door openings. Separating samples scheduled for frequent inspection from long-term storage can further reduce environmental disturbances and improve study consistency.

The adjustable shelving system also allows researchers to optimize airflow around stored materials. Leaving adequate clearance between shelves and avoiding overloading individual levels helps maintain uniform temperature and humidity distribution throughout the chamber, particularly during heavily loaded stability studies.

Energy Efficiency and Operating Costs

The Thermo Forma 3940 was engineered for continuous operation in pharmaceutical and research laboratories where environmental chambers frequently operate around the clock for months at a time. Its combination of refrigerated cooling, insulated cabinet construction, and precision microprocessor controls helps maintain stable environmental conditions while minimizing unnecessary compressor cycling.

Compared with glass-door environmental chambers, the insulated solid-door configuration provides additional thermal efficiency by reducing heat gain from the surrounding laboratory environment. The absence of a viewing window improves insulation, decreases refrigeration workload, and helps maintain chamber stability during long-duration studies. For laboratories conducting stability testing over several months or years, these improvements can contribute to lower operating costs while reducing environmental fluctuations.

The chamber's directed airflow system also improves overall efficiency by distributing conditioned air evenly throughout the cabinet. Uniform airflow reduces localized hot or cold spots, allowing researchers to utilize more of the available chamber volume without compromising environmental consistency.

Key Specifications

Specification	Details
Manufacturer	Thermo Forma
Model	3940
American Instrument Exchange SKU	3158? INC
Chamber Type	Refrigerated Environmental Chamber
Chamber Capacity	Approximately 821 L (29 cu. ft.)
Chamber Material	Stainless Steel
Exterior Construction	Powder-Coated Steel
Door Configuration	Solid Insulated Door
Temperature Range	0°C to 60°C
Temperature Resolution	0.1°C
Temperature Accuracy	±0.1°C
Temperature Uniformity	±0.3°C (25°C–37°C)
Humidity Range	Ambient to 95% RH
Humidity Control	Microprocessor Controlled
Airflow System	Directed Airflow Plenum
Controller	Digital PID Microprocessor
Interior Lighting	None (Solid Door Configuration)
Interior Dimensions	Approximately 38" W × 28" D × 54" H
Exterior Dimensions	Approximately 48" W × 36" D × 78" H
Shelving	Adjustable Stainless Steel Shelves
Alarm System	Audible and Visual
Electrical Requirements	230 V
Approximate Weight	Approximately 700 lb

Specifications are believed to be accurate but may vary depending on factory-installed options. Please verify all specifications prior to purchase.

Frequently Asked Questions

Why choose the solid-door version instead of the glass-door Thermo Forma 3940?

The solid insulated door provides better thermal insulation and eliminates exposure to ambient laboratory light. Laboratories working with photosensitive pharmaceuticals, biological materials, or long-term stability studies often prefer the solid-door configuration because it helps maintain more consistent environmental conditions while improving overall energy efficiency.

Is the Thermo Forma 3940 designed specifically for pharmaceutical stability testing?

Yes. The 3940 is widely used for ICH stability studies, shelf-life testing, environmental simulation, and other applications requiring precise temperature and humidity control over extended periods. Its large chamber also makes it well suited for studies involving numerous samples or multiple product batches.

Can the chamber operate below room temperature?

Yes. Unlike standard laboratory incubators, the Thermo Forma 3940 incorporates a refrigerated cooling system that allows operation from 0°C to 60°C, enabling both refrigerated storage and elevated-temperature environmental testing within the same instrument.

Does the large chamber compromise temperature uniformity?

No. The chamber uses a directed airflow plenum system that continuously circulates conditioned air throughout the cabinet to minimize temperature variation between shelves. Independent testing specifications indicate excellent temperature uniformity even with a large chamber volume when the unit is loaded appropriately.

What types of products are commonly tested inside this chamber?

The Thermo Forma 3940 is frequently used for pharmaceuticals, biologics, vaccines, medical devices, packaging materials, diagnostic products, food products, agricultural samples, botanical research, and other materials requiring controlled environmental conditions during storage or testing.

Is this environmental chamber suitable for GMP or regulated laboratory environments?

Many pharmaceutical manufacturers, biotechnology companies, and quality assurance laboratories use chambers like the Thermo Forma 3940 for regulated testing because they provide programmable environmental control, alarm systems, and stable operating conditions that support documented laboratory workflows. Final qualification requirements should always be determined by the individual laboratory's validation protocols.

Why is a refrigerated environmental chamber preferable to a standard incubator for stability studies?

Standard CO₂ incubators are optimized for cell culture and typically operate above ambient temperature. Refrigerated environmental chambers offer a much wider operating range, precise humidity regulation, and programmable environmental conditions required for stability testing, accelerated aging studies, and product qualification.

Why purchase a refurbished Thermo Forma 3940 from American Instrument Exchange?

Purchasing a refurbished Thermo Forma 3940 from American Instrument Exchange provides access to a premium large-capacity environmental chamber at substantial savings compared with purchasing new equipment. Every chamber is inspected and tested prior to shipment and includes a 90-day warranty, providing confidence that it is ready to support demanding laboratory applications.

Testing Procedures for Used and Refurbished Laboratory Incubators
Ensure Quality and Stability Before Use

Used and refurbished laboratory incubators from American Instrument Exchange are thoroughly tested to ensure optimal performance and temperature stability with laboratory safety standards. Each unit undergoes a detailed inspection and functionality assessment to meet the needs of research, clinical, and industrial labs.

Why Testing Used Laboratory Incubators Is Essential

Before a laboratory incubator is reintroduced into any work environment, it must be tested for:
• Temperature uniformity and accuracy
• Airflow and humidity control (if applicable)
• Door seal integrity and insulation effectiveness
• Electrical and safety system compliance

Comprehensive testing reduces the risk of culture loss, contamination, and equipment failure—especially critical in applications involving cell culture, microbiology, pharmaceutical research, and diagnostics.

Our multi-point testing protocol for used and refurbished incubators ensures reliability, safety, and performance across all models and brands.

Key Testing Procedures for Refurbished and Used Laboratory Incubators

1. Initial Visual Inspection
• Check for cosmetic damage, corrosion, and wear to exterior surfaces, door hinges, and gasket seals
• Inspect power cord, wiring, and display panel for any defects or signs of tampering
• Confirm that shelves, chamber components, and internal fixtures are present and undamaged

2. Functional Testing
• Power on the incubator and verify all display indicators and alarms function correctly
• Test door latch and seal mechanisms for proper closure and insulation
• Run basic temperature cycles to ensure the unit maintains stability over time

3. Temperature Accuracy and Uniformity Tests
• Test internal sensors and controllers using temperature probes
• Measure temperature consistency at multiple chamber locations over several hours
• Confirm that programmable temperature settings respond accurately

4. Airflow and Humidity Control (if applicable)
• Test internal fan operation and airflow distribution
• For humidified incubators, inspect and test humidity reservoirs, sensors, and control systems
• Check for condensation buildup and confirm environmental stability

5. Electrical Safety and Compliance Checks
• Ensure all electrical components are properly grounded
• Perform insulation resistance and leakage current tests
• Verify compliance with current electrical safety standards for laboratory equipment

6. Final Quality Assurance Checklist
• Perform full cycle testing at various temperature setpoints
• Document performance benchmarks and results

All refurbished incubators from American Instrument Exchange are backed by our commitment to quality and precision. With our strict testing procedures, you can rely on your incubator to deliver dependable results from day one.

Repair and Refurbishment Protocol for Used Laboratory Incubators
Performance and Quality from American Instrument Exchange

At American Instrument Exchange, every used laboratory incubator we sell goes through a repair and refurbishment protocol. Whether it’s a standard, CO₂, or refrigerated incubator, our goal is to restore each unit to laboratory-level performance—ensuring temperature accuracy, environmental stability, and long-term reliability in your lab.

Why Choose a Refurbished Laboratory Incubator from American Instrument Exchange?

• Fully tested for performance and safety
• Backed by a warranty
• Cost-effective alternative to new equipment
• Environmentally sustainable through reuse and restoration
• Refurbished by expert technicians with decades of lab equipment experience

Step-by-Step Refurbishment Protocol

Every incubator at American Instrument Exchange follows this comprehensive, multi-stage process:

1. Initial Intake & Inspection
• Visual inspection for cosmetic wear, corrosion, dents, or broken components
• Mechanical assessment of door hinges, gaskets, seals, and chamber components
• Document any missing parts or issues requiring repair or replacement

2. Cleaning and Decontamination
• Thorough internal and external cleaning using non-abrasive solutions
• Decontamination/cleaning of surfaces to remove biological, chemical, or particulate residue
• Cleaning of removable parts (e.g., shelves, trays, etc.)

3. Mechanical and Electrical Repair
• Repair or replacement of worn mechanical components such as door latches, fans, hinges, and seals
• Evaluation and repair of control panels, switches, thermostats, and displays
• Inspection and testing of wiring, fuses, relays, and power supplies

4. Environmental Control System Assessment
• For CO₂ incubators: CO₂ sensors, regulators, and gas delivery systems are tested
• For refrigerated incubators: compressors, condensers, and cooling systems are evaluated for performance and leaks
• Fan motors and airflow systems are tested to ensure uniform environmental conditions

5. Temperature and Sensor Testing
• All temperature sensors and controllers are tested using thermometers/probes
• Uniformity and accuracy tested at multiple chamber locations
• For humidified or CO₂ incubators, humidity and CO₂ stability are verified

6. Safety System Testing
• Test of over-temperature protection systems and alarms
• Evaluation of door sensors, safety interlocks, and power failure recovery

7. Final Quality Control and Documentation
• Full performance test run over 24 hours
• Validation of setpoints for temperature, CO₂ (if applicable), and humidity (if applicable)
• Final inspection and cleaning before packaging
• Complete service report

Trust the Experts at American Instrument Exchange

With over 50 years in the lab equipment industry, American Instrument Exchange is a trusted source for high-quality refurbished laboratory incubators. Our proven refurbishment protocol ensures every unit is reliable, accurate, and ready to meet the demands of your lab from day one.

Warranty Information

All used equipment sold by American Instrument Exchange is refurbished/reconditioned, tested to meet specifications, cleaned, and comes with a 90-day warranty from the date of shipment unless otherwise specified. New products include a warranty from the manufacturer. Your warranty is only valid if you have paid your invoice. If your invoice is over 30 days old, warranty work will not be performed until your invoice is paid in full. American Instrument Exchange is not liable for any special or consequential damages that result from the use of, or the inability to use, the materials on this site or the performance of the products,

Exceptions include international sales and items that are agreed to be sold with a lesser warranty or items that are agreed to be sold “as is.”

Should there be visible shipping damage to packaging or concealed shipping damage to item(s) supplied, buyer must communicate such damage to the delivering entity or carrier upon receipt first and to American Instrument the same day item is accepted / signed for. Failure to do so voids warranty. Customer decision to involve / procure third party or OEM service other than American Instrument or AIE assigned vendors to resolve in-warranty instrument failure or defect without first placing a service call to American Instrument voids warranty.

Return & Cancellation Policy

American Instrument Exchange will authorize the return of and issue a full refund for any equipment that is not working as represented and could not be replaced or repaired to the customer’s satisfaction by AIE or a representative of AIE during the warranty period. Returns without prior authorization and an RMA number will not be accepted.

Customers are responsible for proper packaging of the equipment and all included accessories. American Instrument will pay for insurance and shipping costs. Non-inventory items bought specifically to fill customer orders may possibly be returned, but on a case by case basis.

Customers who cancel orders after refurbishing has begun or after delivery where there are no equipment performance issues may be subject to a Restocking/Cancellation Fee of 20% or more and responsible for shipping costs for both the delivery and return.

Ongoing and Extended Support Options

American Instrument Exchange is able to provide additional repair and support services outside the warranty terms for most products that sell.

For biosafety cabinets, clean benches, chemical fume hoods, and other clean air products our team at AIE Laboratory Services can provide certifications, repairs, decontaminations, and other services for customers throughout New England, and guidance and limited technical assistance for any customers in the US and Canada for new or refurbished biosafety cabinets purchased from American Instrument Exchange.

For all other products, the repair service team at American Instrument Exchange can provide both field and depot repair evaluations. We can easily schedule and coordinate the pick-up and transportation of your malfunctioning equipment. By offering hourly rates lower than most OEM service providers and eliminating travel time for technicians, we help reduce repair costs. Furthermore, our lab depot repair service minimizes or eliminates scheduling delays. Our experienced service technicians are qualified to restore your equipment to factory specifications.

Please contact our team at info@americaninstrument.com for more details.

FAQ

Does the equipment come with a warranty?

Yes, all equipment from American Instrument Exchange comes with a warranty.
Used/reconditioned/refurbished equipment is tested to make sure it operates to the manufacturer's specifications and comes with a 90-day warranty (unless otherwise noted). New equipment comes with a warranty from the manufacturer.

How do you test and recondition the equipment?

Testing requirements vary across all the equipment categories we sell. Temperature controlled units are tested with NIST traceable probes and data loggers. Gaskets, external housing, glass, handles, controls and control screens are all thoroughly inspected for integrity and functionality.
We test all equipment using the manufacturer's parameters and specifications to confirm that the unit operates properly.

How do products ship from American Instrument Exchange?

We can ship products both nationally and internationally using a well-established network of transporters. Smaller items will ship via UPS. Larger equipment will be palletized and shipped either LTL or air-ride, depending on the specific equipment and/or delivery requirements.

Return and order cancellation policy

American Instrument Exchange will accept the return of any product that is not working as represented and could not be replaced or repaired to the customer's satisfaction during the warranty period. Customers who cancel orders after refurbishing has begun will be subject to a cancellation and restocking fee of between 20% and 40%.

Are discounts available for educational or non-profit institutions, or for bulk purchases?

Yes – call or email us today with a list of equipment you're looking for and we can potentially put together a quote that includes a discount.

How does your price matching policy work?

We strive to keep our pricing competitive and reasonable. If you find comparable items for sale at a lower price from other vendors please send us a link and or quote for the item and we'll do our best to match or beat the price.

Can I see the equipment in person before committing to a purchase?

Customers are welcome to make an appointment to view equipment in our warehouse. Given our workload we may not be able to test or clean the equipment prior to your arrival if you have not committed to an order.

1023 Western Avenue is a working warehouse, not a showroom, and customers should dress appropriately and wear closed toe shoes.

Can I ship products that I purchased elsewhere to American Instrument for repair?

Yes – please see our repair services page for more information.