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Our FD and HD-21 models are floor-style environmental test chambers with 18.962 cubic feet (536.944 liters) of working volume, and external dimensions of 41.5"W x 52.5"D x 76.5"H (1055W x 1260D x 1945H mm), including two low to high-temperature range configurations as shown below. 

The HD configuration, includes a steam generator and dehumidification coil, giving a humidity range of 10%RH to 98%RH.

FD/HD Configurations:

  • FD - Temperature only
  • HD - Temperature and humidity capability

Available in two standard temperature ranges:

  • 500 Series ~ -37°C to +180°C (-35°F to +356°F)
  • 200 Series ~ -65°C to +180°C (-85°F to +356°F)


Interior: 32"Wx 32"D x 32"H
  815W x 815D x 815H mm
Exterior: 41.5"W x 52.5"D x 76.5"H 
  1055W x 1260D x 1945H mm
Volume: 18.962 cubic ft
  536.944 Liters
Temperature: -85°F to 356°F
  -65°C to 180°C
Humidity: 10% to 98%
Rise Rate*: 3.88 °C/minute
Pull Down Rate*: 1.5 °C/minute
Electrical Supply: 208 or 230V, 3 Phase, 60 Hz
Full Load Amps: FD - 45 Amps 
  HD - 51 Amps

*Rise and Pull-down rates calculated using IEC 60068-3-5 standard. Custom options available



  AES|XChange-Operating and Data Management Dashboard

Dashboard view enables chamber control at the chamber, at a desktop, or remotely via laptop or tablet

Profile Builder has drag-and-drop, web-browser functionality

Data Logging with onboard, multi-year logging of live and current data, anyplace anytime

Communication and Control uses standard, well-documented JSON API for easy integration with other test platforms

Security decreases test interference with three authentication methods and six permission levels 

View all the benefits of AES|XCHANGE

Watlow F4T Programmable Controller

Features a 4.3” capacitive touchscreen minimizing the chance for error. Ethernet communication supported by AES|XCHANGE

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100 OHM Platinum RTD  is a highly-accurate sensor made from platinum components for increased sensitivity

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Data Loggers

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Safety Measures

We offer multiple types of safeties on our test chambers to help protect your product and your test chamber if anything malfunctions.

Heat Fuse: (Standard)

A heat fuse or thermal fuse, will interrupt the flow of electricity to the test chamber and shut it down if it reaches a certain temperature.

High Temperature Safety: (Standard)

A digital set temperature safety that will shut down the test chamber if it goes over a certain temperature.

High/Low Temperature Safety:

A digital set temperature safety that will shut down the test chamber if it goes over a certain temperature or below a certain temperature.


Optional Features:

  • Shelf Modification (placement, size, number)
  • LN2 Boost Cool
  • CO2 Boost Cool
  • Custom Porting Sizes
  • Dry Nitrogen Purge
  • Water Cooled Condenser
  • Self Contained Water Recirculating System (HD Only)
  • Water Demineralizer Cartridge System (HD Only)
  • Heater for Window
  • Noise Reduction Package
  • Desiccant Air Dryer (for lower RH Range)
  • Variable Speed Fan*

*Only available on 13 cubic foot models and up



A unique feature of an Associated Environmental Systems test chamber is the variable speed fan we use to control airflow in the chamber. The fan is a variable frequency drive, specifically an ACS310 by ABB, that is dedicated to optimize the variable torque operation of our fans. The speed of the fan can be controlled through a profile or with a control loop on the AES|ONE.

ramp rate performance by associated environmental systems


Customers require the ability to reliably test as much product as possible in as little time as possible. AES standard cascade refrigeration systems have the fastest standard change rates of any environmental test chamber manufacturer, with average pull down times of 2.5°C/ minute and average ramp rates of 4.4°C/ minute. AES chambers allow you to maximize product testing efficiency without sacrificing quality.

mike designing chamber by associated environmental systems


All test chambers incorporate non-magnetic welded type 304 stainless steel inner chambers, a cold-rolled steel, powder coated exterior, efficient low "K" factor thermal insulation and direct drive-shaft powered forced air circulation along with open wire nichrome resistance elements generating ultimate functionality while maintaining a pleasant laboratory appearance. State-of-the-art regulation techniques result in high accuracy and long term stability.

Heating System

Heating System

AES heating systems are all-electric and pass air over fast-response low watt density resistance heaters with a ceramic core insuring a long reliable life with no down time. The combination of airflow, instrument response and these fast reacting heaters give very accurate and straight-line control of temperatures. Our heating systems support temperatures upwards of 180°C (356°F) and heaters may be controlled independently or in unison. Heating systems are located in a plenum so that test items are not subject to direct radiation.

cascade compressor cooling system

Cooling System

AES test chambers are either built with a single stage, self-contained mechanical refrigeration system [-37°C (-35°F)], or a two-stage, cascade mechanical refrigeration system [-65°C (-85°F)]. Depending on the size of the cooling system needed, more than one compressor will be included, or a small scroll compressor will be used to save space. Both refrigeration systems also come with an option for water cooling.


Liquid vs Air Cooled Test Chamber

Air cooling will heat up the room that the test chamber is located in, is usually less power efficient, slows the pull down times of the chamber, and needs more space, but costs less and is simpler.

The water cooling option does not heat up the room it is located in, is more power efficient, and has a smaller area compared to the air cooled option, but is more complicated, costs more, and needs a water supply.

Steam generating humidifier

Humidity System

We use a vapor generator system to control the humidity within our test chambers. The vapor generator is a closed steam generator that can be sized to fit any chamber which offers quicker steam generation, but also can result in built up sediment. The humidity range on most test chambers is 20% to 98% +/-2% RH (Relative Humidity). The range can be lowered to roughly 5% RH with the use of a dry air purge.


Continual Humidity Package

Available for any test chamber with a humidity system, the continual humidity package allows users to recycle water used for humidity testing, eliminating the need for hard-plumbed water access and expanding the capability of autonomous testing.

  • Tower Level Control
  • 6 or 10 External Gallon Storage Tank
  • Recirculation Pump
  • Optional: Demineralizer Cartridge
  • Optional: Desiccant Dehumidifier
  • Optional: Chilled Mirror Humidity Sensor
dry air purge dehumidifier

Dry Air Purge/Dry Nitrogen Purge

The dry air purge features a desiccant dehumidifier which pulls moisture from the air using an active desiccant material, a hygroscopic substance that induces dryness in its vicinity. As the ultra dry nitrogen, which has a dewpoint of -70 degrees, is introduced into the enclosed cavity, it expands and places the test item under pressure, removing any residual moisture from the test product and internal test chamber environment.



Desiccant dehumidifiers have a more complex principle of operation but perform exceptionally well in colder climates or when there is a large amount of moisture in the air.

Temperature/Humidity environmental test chambers are commonly paired with dry air purge systems which reduces the humidity index of the chamber interior at a much quicker rate than a natural rate.

Temperature only chambers may also benefit from a dry air purge system if the user wishes to control the residual moisture that is generated with temperature changes within the chamber interior.
Dry nitrogen may also be used as a dry gas purge method.

Liquid CO2 Boost

Liquid LN2 or COBoost

Via an endothermic process, directly injected liquid carbon dioxide instantly drops the temperature of the test chamber interior, ideal for stress tests and efficient thermal dissipation. CO2 can lower the chamber's internal temperature almost instantaneously to -73°C (-100°F). Liquid CO2 is available to customers in either a bulk system stand-alone tank, or a cylindrical system which stores much smaller amounts in multiple attached vessels.

Liquid nitrogen is directly injected into the test chamber to both expand achievable temperature ranges and raise the temperature change rate. Upon contact with the air inside the test chamber, following the same thermodynamic principle as the CO2 boost, liquid nitrogen can rapidly decrease the interior chamber temperature. Liquid N2 boost can quickly lower the temperature to a cryogenic temperature of -185°C (-300°F).



Unlike CO2 which has a boiling point of -57°C (-70.6°F), liquid nitrogen has a boiling point of -196°C (-320.8°F), therefore have pull-down rates that are much faster.

LN2 or CO2 cooling option for the FDP-4246 should only be considered in bulk form.  Cylinder option for the sizable workspace is not ideal.



CO2 Scrubber Cartridge

A dependable filtering system designed to eliminate contamination caused by moisture, oil and dirt in bulk or bottled liquid CO2 supplies. Suitable for both 1000 psi and 300 psi service and assure pure CO2 at valves and metering orifices, completely eliminating problems of clogging and erratic operation.

Manifold for 6 Cylinders (MLC-6)

Included with the cylinder based CO2 cooling system, the manifold system is designed to regulate and monitor the vaporized gas coming from cryogenic cylinders. This system may be used to test to the MLC-6 specification.

CO2 Tank to Test Chamber Hose (DAK-6)

Included with the bulk order CO2 cooling system, the tank to test chamber hose provides safe and effective delivery of liquid CO2 to the chamber interior. This system may be used to test to the DAK-6 specification.


Bulk System

  • -18°C (0°F) and 300 psi
  • This larger reserve system has a higher initial cost but then offers a much lower per pound CO2 cost to customers and is recommended for long duration testing or multi-chamber operation.

Cylindrical System

  • The cylindrical system stores much smaller amounts of CO2 in attached vessels, stored at room temperature and 1000 psi.
  • This option is recommended for short duration testing or long term testing in smaller test chamber sizes.
xchange splash dashboard by associated environmental systems

Control and Data Collection

Digital chart recorders allow users to escape the limitations of pen and paper data recorders and provide a way to instantly monitor and store valuable testing data.

We offer a variety of controller and data logging options to fit your needs

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cannot fit through standard doorway


This model CANNOT fit through a standard 34" wide doorway. Although some AES test chambers can have modifications to allow for a modular assembly on-site, a Model 21 test chamber CANNOT be modified.

Casters and floor stands may be applied to any test chamber series (except walk-ins) upon request, to optimize mobility within your facility.