Heating System
The heating systems in AES chambers are all-electric and pass air over fast-response, low-watt-density resistance heaters with a ceramic core, ensuring a long, reliable life with no downtime. The combination of airflow, instrument response, and these fast-reacting heaters give highly accurate and straight-line control of temperatures. These 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 test items are not subject to direct radiation.
Standard temperature ranges: -37°C to +180°C (-34.6°F to 356°F) | -70°C to +180°C (-94°F to 356°F)
Precision: ±0.5°C
Cooling System
The cooling system in AES chambers consists of a self-contained mechanical refrigeration system with a single-stage or cascade configuration. You’ll have the option of air-cooling or water-cooling. Air-cooling comes with easier installation and is less expensive than water-cooling. However, it produces slower pulldown rates.
Water-cooling systems result in faster pulldown rates and are more energy efficient, but they require a dedicated, conditioned water supply and are more complicated to install.
You can supplement your system with boost cooling, employing liquid nitrogen (N2) or carbon dioxide (CO2) for even faster pull-down rates. It's a great option for stress tests that require rapid cooling. Even without boost cooling, AES standard cascade refrigeration systems have the fastest standard change rates of any environmental test chamber manufacturer.
Air Circulation
Air circulation is crucial for environmental testing. AES’s chambers have proprietary baffle and fan design combinations that optimizes temperature conditions within the workspace.
AES uses vapor generator systems to give you precise control over the humidity conditions of your chambers’ internal workspaces. The vapor generator system is a closed stainless steel or copper tube. An element heats a constant water source creating vapor or steam that travels through the tube and mixes with conditioned air in a plenum before moving into the workspace. Notably, this water source must be treated and demineralized to avoid contaminating the test.
This system yields a standard relative humidity (RH) range between 10% and 98%.
Optional Features to Increase Humidity Range
High Humidity Sensors let you measure humidity as high as 98% RH.
Dry Air Purge Through Desiccant Air Dryers can achieve humidity as low as 5% RH. It compresses air through a desiccant system, absorbing the moisture before it moves into the workspace.
Dry Nitrogen Purges prevent condensation and frost from accumulating on DUT surfaces at colder temperatures by forcing out the moisture-heavy air. This also prevents the oxidation of metals at high temperatures.
Recirculating Desiccant Air Dryers are a more feasible option for larger chambers. Air is circulated through a desiccant system and then returned to the chamber, often cycled through a honeycomb wheel that releases captured moisture into the external workspace.
Associated Environmental Systems has developed a Dew Point Calculator to help you determine whether you'll need optional features for your humidity systems.