Associated Environmental Systems offers a range of prefabricated, tight-tolerance environmental walk-in rooms that are easy to ship and install. Major features include:

 

• Forced air circulation systems distribute air evenly and constantly recirculate it, maintaining uniform and accurate temperatures and humidity.
• Temperature Ranges are from -73°C (-100°F) to +85°C.
• Refrigeration system meets the room's load demand and operates continuously in cooling mode. Single-stage mechanical units operate at -35°C and above and two-stage cascade units at below -35°C.
• Electric heating system provides very accurate and straight line control of temperatures. System is reliable and has a long life.
• Humidity System choices are the conditioned fine Mist System or the Steam Generator System. Different ranges are available including special dehumidity ranges to 5% RH.
• Prefabricated room construction consists of modular, sandwich-type panels with a metal skin inside and outside. Panels are easy to ship and assemble.
• Multipane viewing windows can be ordered in custom sizes.
• Incandescent or fluorescent lighting is vapor-proofed and sealed.
• Instrumentation consists of single or two-channel microprocessor programmers with an accuracy of ±.25°C or better at the sensor. Other options include: RS-232C, RS-422A, IEEE-488 interface.
• Safety standard is a redundant control circuit with its own controller and failsafe contactor. Many other options are available.

 

 

 

AES supplies a refrigeration package that supports the load demands of the Walk-In Environmental Room.

 

• Single-stage mechanical refrigeration systems operate at -35°C and above.
• Two-stage cascade refrigeration systems (air cooled or water cooled) operate below -73°C.

 

• Operate continuously in cooling mode.
• Provide a hot gas by-pass system to automate capacity reduction when the room is at the set point temperature.
• Are constructed with high quality components including: liquid line solenoids, liquid sight glass, dryers, strainers, and TX valves.
• Contain Copeland semihermetic (or equal) compressors.
• Contain Penn (or equal) controls.
• Comply with ASHRAE guidelines for piping and rating.
• Are factory-assembled and tested.
• Are simple to maintain because components are easily accessible and clearly labeled.

 

Up to 5 HP units can be mounted on the roof of the walk-in room. Larger units are installed on the floor next to the room.

 

Comprehensive piping diagrams, schematics, and charging data are available for our environmental walk-in rooms.

 

Rooms are constructed of prefabricated metal tongue and groove sectional panels. An assembled room has continuous steel perimeters to hold panels tightly in place.

 

Panel features include:

• 100% insulation
• Light weight for easy handling – average weight of the largest panel is 84 lbs.
• Alignment pins for accurate fit.
• Steel straps connect locking arms with locking pins on opposite sides of panels.
• Cam-actuated locks ensure tight fits and accommodate frequent assembly/disassembly for relocating or enlarging the room.

Viewing Windows

The standard multipane window has a 14" by 23" viewing area. Thermostatically controlled heater wire in the window casing minimizes condensation and frost formation on the window surface. Custom size windows are available.

Lighting

All lighting fixtures are vapor proof and sealed. Both incandescent and flurorescent lighting fixtures are available.

 

Incandescent lighting is recommended for high temperature units operating above +110°F and low temperature units operating below 0°F.

Forced Air Circulation Systems

All walk-in rooms incorporate forced air circulation. Differences in the size of the test chamber and its internal configuration are accommodated by various airflow patterns, including horizontal, vertical, or a combination of both. These provide an even distribution of air and tight temperature control. Noise is also a consideration.

 

The air circulation systems use external heavy duty motors to distribute air evenly and constantly recirculate it, maintaining uniform and accurate temperatures and humidity. The high quality motors have internal cooling fans, protectors, and stainless steel shafts. Aluminum or stainless steel squirrel cage blowers circulate the air. All mixing is within a plenum that is external to the walk-in room work area.

 

In tight tolerance environmental walk-in rooms, air must be evenly distributed and constantly recirculated at a higher than normal rate in order to maintain uniformity and accuracy. A portion of one wall of the room is devoted to a conditioning plenum. Air is drawn into the lower part of the plenum through a set of cleanable filters, across an evaporator coil and vertically across electric heaters. The air then enters centrifugal fans and is discharged into a perforated ceiling plenum. The air flows vertically downward in the room and is returned horizontally through the cleanable filters to the wall plenum.

Electric Heating System

The combination of airflow, instrument response, and fast-reacting heaters provides very accurate and straight line control of temperatures.

 

Air is passed over the fast response, low watt density heaters with ceramic cores. This type of system provides very accurate air and humidity control. A separate instrument precisely controls the heat level.

 

The heating systems have a long life and are very reliable, with no down time.

Instrumentation

Instrumentation consists of either single or two-channel microprocessor programmers with an accuracy of ±.25°C or better at the sensor. The sensors are fast acting 100 Ohm. platinum type.

 

Other options include: RS-232, IEEE-488 interface.

Safety

Standard is a redundant control circuit with its own controller and failsafe contactor. To prevent thermal runaway, the safety control shuts off power to the heater circuit and the circulation blowers continue to distriibute heat within the room. This feature is particularly important if there are heat-generating items in the walk-in room. When the temperature goes down, the safety control closes and power is restored to the heaters.

 

Other available safety options are: High Temperature Safety with Complete Shut Down of Room with Manual Reset and Visual Indication, Low Temperature Safety with Complete Shut Down of Room with Manual Reset and Visual Indication, Both High and Low Temperature Safety with Manual Reset on Both and Visual Indication, Audible Alarm, and Remote Station Alarms.

Electrical Requirements

Standard power requirements include 208V 3PH 60HZ, 220/240V 3PH 60HZ, 460V 3PH 60HZ, 208/220V 1PH 60HZ. Other power requirements are available upon request.

Temperature Ranges

Various ranges can be provided, including fast change rates with your product load. Ranges from -73°C (-100°F) to +85°C are available.

Humidity

Standard ranges available are: 20% to 95% ±5% RH. 10% to 98% ±2% RH. Different ranges available including special dehumidity ranges to 5% RH.

Humidity System

Two Humidity systems are standard:

 

• Fine Mist System is recommended when doing continuous testing with high live loads.
• Steam Generator System is recommended for rooms being used for low and high humidity testing within the System range of +40°F to +130°F.

 

The conditioned Fine Mist System uses your local water supply. Steam is created within a plenum outside the room area by spraying a fine mist over a stainless steel sheath-type heater. The circulation system carries this steam throughout the walk-in room.

 

The Steam Generator System uses an external self-contained steam generator with all necessary safety and water level controls to provide humidities to saturation point within the walk-in room.