Practical Guide to Choosing a Climate Chamber

Choosing the climate chamber for your laboratory requires carefully evaluating several technical parameters: temperature range, humidity control, usable volume, applicable standards, and application sector. A poor choice results in non-compliant tests, unrepeatable results, and additional costs.

This guide analyses the fundamental criteria for choosing between climatic chambers, environmental chambers and thermostatic chambers, helping you identify the model best suited to your operational needs.

Climatic, Environmental, or Thermostatic Chamber: The Differences

The first step in choosing is to understand what type of chamber you need. The three main families are distinguished by the environmental parameters they control:

• Climatic chamber — controls temperature (-25°C / +70°C) and relative humidity (10-98% RH). It is the most versatile type and the most popular for stability, aging, and regulatory compliance testing.
• Environmental chamber — reaches extreme temperatures (-70°C to +180°C) with optional humidity. Required for thermal stress, burn-in, and thermal cycling tests according to military and aerospace standards.
• Thermostatic chamber — controls only temperature (-25°C to +70°C), without humidity. Suitable when the test requires only thermal control.

Rule of thumb: If your tests involve controlling relative humidity, you need a climate chamber. If you need temperatures below -25°C or above +70°C, you need an environmental chamber. If you only need a standard temperature range, a thermostatic chamber will suffice.

Temperature Range: How to Choose

The temperature range is the most critical parameter. It must be defined based on:

• Regulatory reference: Each standard defines test temperatures. For example, the ICH Q1A qualification for pharmaceuticals requires 25°C/60% RH and 40°C/75% RH. Military MIL-STD-810 tests can require -54°C to +71°C.
• Operating margin: Always choose a range at least 5-10°C wider than the test temperatures. A chamber operating at the limit of its range loses accuracy and accelerates component wear.
• Ramp Rate: For tests with rapid thermal cycling (e.g. automotive thermal shock), the rate of thermal transition is as important as the range itself.

Usable Volume: How Big Should It Be?

The chamber's internal volume must be sufficient to accommodate the samples while ensuring uniform air circulation. The CB-CS series FDM climatic chambers are available from 140 to 2,300 liters.

• 140-300 liters: ideal for electronic components, small pharmaceutical samples, laboratory materials
• 300-700 liters: for medium-sized automotive components, battery modules, multiple samples
• 700-2,300 liters: for testing complete assemblies, panels, structural elements
• Walk-in (over 2,300 liters): For testing entire finished products — discover FDM walk-in chambers

Please note: The usable volume indicated by the manufacturer represents the total internal space. In practice, samples should not occupy more than 30-40% of the volume to ensure thermal uniformity.

Relative Humidity Control

Humidity control is what distinguishes a climatic chamber from a thermostatic one. climatic chambers operate within a range of 10-98% RH with an accuracy of ±2-3% RH.

Humidity control is essential for:

• Pharmaceutical stability testing according to ICH guidelines (25°C/60% RH, 30°C/65% RH, 40°C/75% RH)
• Corrosion and humidity resistance tests (IEC 60068-2-78)
• Tests on hygroscopic materials (fabrics, paper, polymers)
• Microbiological growth tests and food shelf-life tests

If your tests also involve exposure to light, consider the LCB-LCS series FDM illuminated chambers, which integrate specific lamps for photostability and plant growth tests.

Regulations and Standards: Which Chambers for Which Tests?

Each sector has its own regulatory requirements, and the chamber must be able to meet the required parameters. Here are the most common associations:

• ICH Q1A/Q1B (pharmaceutical) → ICH FDM chamber
• IEC 60068 (electronics environmental testing) → Environmental chamber
• MIL-STD-810 (Defense) → Extended Range Environmental Chamber
• UN 38.3 (lithium batteries) → Battery test chamber
• ISO 4892 (UV aging) → FDM UV chamber
• EN 12390-9 (freeze-thaw concrete) → FDM concrete chamber

If you are unsure which standard applies to your industry, FDM Technical Support can help you define your specific test requirements.

Accessories and Customizations

In addition to the basic parameters, a climatic chamber can be equipped with accessories that expand its capabilities:

• Cable glands and portholes: for connecting external sensors or visually monitoring samples during testing
• Additional shelving: to maximize load capacity with multiple samples
• Data logger: for automatic documentation of test conditions (required for IQ/OQ/PQ qualification)
• Remote connection: for monitoring and control from PC or mobile device
• Custom doors: for loading large samples

FDM offers custom solutions for needs that go beyond standard configurations: special volumes, integration with external systems, multi-camera configurations.

The FDM Solution

FDM Environment Makers has been designing and manufacturing climate chambers in Italy since 1949. Each chamber is built to ensure precision, reliability, and compliance with the most demanding international standards.

With a catalog that ranges from CB-CS climatic chambers to environmental chambers for extreme tests, and the possibility of creating customized solutions, FDM is the ideal partner for laboratories of all sizes.

Discover FDM Climatic Chambers or contact us for a free technical consultation to help you choose the right model.

If the protocol includes CO₂ concentration control, the FDM range also includes the CO₂ test chamber.

Frequently Asked Questions About Choosing a Climate Chamber

What is the difference between a climatic chamber and an environmental chamber?

The climatic chamber controls temperature (-25°C/+70°C) and relative humidity (10-98% RH). The environmental chamber reaches extreme temperatures (-70°C/+180°C) with optional humidity. A climatic chamber is required for standard humidity tests; an environmental chamber is required for severe thermal stress.

How big should the climate chamber be?

Samples should not occupy more than 30-40% of the usable volume to ensure thermal uniformity. For small components, 140-300 liters are sufficient; for complete assemblies, 700-2,300 liters or walk-in chambers.

Do you need humidity control?

Yes, if the tests involve specific humidity conditions (ICH tests, corrosion tests, food shelf life). No, if only thermal cycles are needed without humidity requirements—in that case, a thermostatic chamber is sufficient.