Construction of a Climatic chamber

There are several variables that can affect the durability of a product. Climatic chambers are made of materials that ensure their durability and optimize their performance so that they can provide accurate and reliable data regarding the many factors that can cause deterioration and failure of products. Since a Climatic chamber is a miniature environment able to create a wide array of conditions, it is made of durable materials capable of withstanding the conditions that it creates.

Climatic chambers come in several sizes from desktop models to ones large enough to walk in. Regardless of the range of sizes, all Climatic chambers have several elements in common, which include wall design, sealing materials, doors, observation ports, humidity controllers, and temperature settings monitor.

Construction of a Climatic chamber

Walls –

The construction of the walls of a Climatic chamber is an essential part of the design. A major factor in the testing of products is to ensure that the created atmosphere is not contaminated by the surrounding environment. All Climatic chambers are double walled and can be modular or welded. The welded design is preferred since it offers a better seal to the enclosure.

Interior Wall of a Climatic chamber

Sealing Material –

The sealing material for a Climatic chamber has to be resistant to compression, steam, pressure, and temperature variations. The types of materials used to seal doors and windows are silicone, rubber, and certain polymers. The chamber sealant ensures that the chamber is protected against any intrusive factors that could cause harm to the chamber or corrupt the data.

Doors –

To preserve and contain the environment in a Climatic chamber, doors are double walled and mounted with heavy duty hinges with a locking mechanism that completely seals the chamber when closed. The construction of the door is essential to ensuring the integrity of the chamber and blocking any potential ambient contaminants that could distort the test results.

Climatic chamber Self Sealing Door

Controllers –

The control mechanism for Climatic chambers is a proportional integral derivative (PID) controller, which provides continuous modulated data and error values or the difference between the setpoint and measured process variable. The controller takes in the accumulated information and makes automatic corrections in accordance with the proportional, integral, and derivative terms.

A PID instantly and automatically makes corrections to the controlled function. If the particulate humidity falls below the desired setting, the controller makes the necessary adjustments to keep the ratio constant.

Controller

Controller (from weiss-na.com)

Temperature –

The heat for a Climatic chamber is provided by a direct heating coil or wire, which evenly distributes heat to all parts of the chamber. When a Climatic chamber is designed, its size determines the heat range. Large walk-in chambers have a highly complex heating system connected to the air supply, while smaller chambers are able to use a more direct heating method.

The heating elements are normally encased in ceramic. The calculation of the required temperature is computed by the control system once it has been programmed with the parameters for the items of the testing.

Air Supply –

The purpose of the air supply system is to circulate the humidified air in the inner chamber and consists of a circulating motor, circulating wheel or fan, and air duct system. The air supply system is designed to pull in air from the surrounding environment and distribute the humidified air in the chamber.

Humidity System –

There isn’t one single way that the humidity in a Climatic chamber is produced. Some chambers have a water tank that is heated to produce steam that is vented into the chamber, while other systems have spray nozzles. The heating system has water and vapor controls to meet the required international standards for Climatic chambers. In each of the systems, there is an overflow control to avoid having the chamber having too much moisture.

Materials –

One of the key requirements of a Climatic chamber is durability. They are constructed of thick and durable metal sheets that are designed for wear resistance of the highest quality steel. The majority of test chambers are made with a welded steel frame on the exterior and a stainless steel interior liner. They have fiberglass or silicone insulation with a 0.25k factor.

To add to the life of a test chamber, the metals are powder coated and painted for corrosion resistance and ease of cleaning. A key feature of Climatic chambers is their double wall seal that ensures the quality and accuracy of atmospheric tests.