DataPlex engineers designed a digital HVAC system for Zwick Energy Research's mobile HVAC ground equipment built under contract to provide NASA and the U.S. Air Force with the ability to cool avionics as their aircraft and spacecraft sit on the ground in harsh environments such as in a desert. The ZER-HVAC unit operates from -40 to 140 °F (-40 to 60°C) while maintaining a ±1°F setpoint. It controls airflow through up to five ducts, each attached to a specific air inlet vent.
The ZER-HVAC's original design used analog electronics to control the temperature and flow-rate for each duct, but this duct-independent approach had limitations. DataPlex engineers designed a drop-in replacement for the analog electronics, a centralized digital air flow control system that leverage proportional-integral-derivative (PID) feedback to directly drive a number of valves, solenoids and duct louvers. The DataPlex system not only met the difficult technical specifications of ±1°F and the wide temperature range, but it also provided a number of failsafe protocols that otherwise would not have been possible.
As one step towards meeting the challenging specs, DataPlex engineers recommended and received the go-ahead to design custom air flow sensors with greater range, higher reliability and faster response times than those commercially available.
|Space Shuttle at landing|
After every Space Shuttle landing, either at the Kennedy Space Center or at Edwards Air Force Base, the spacecraft undergoes a battery of data downloads, exhaustive systems testing and a final reset as it sits idle. To keep the electronics from overheating and becoming damaged while the main engines are off, the ZER-HVAC unit feds cold air into several ducts attached to the craft.
|B1-B on Tarmac|
The ZER-HVAC unit is used also to keep the equipment on B1 Bombers from overheating as they sit on the Tarmac. The B-1B fills an important niche in the Air Force inventory. After a rough start including a redesign from the original B-1A and a number of timely upgrades, the project is one that remarkably finished on budget. Compared to other active military aircraft, the B-1 has high survivability, great speed, worldwide serviceability and easy maintability, all of which appeals to the Air Force so much that they intend to keep the B1 relevant with upgrades and in service until 2038.
Airborne Warning and Control System (AWACS) aircraft were among the first to deploy during Operation Desert Shield where they immediately established an around-the-clock radar screen to defend against Iraqi forces. Because it could operate in the high desert heat, the ZER-HVAC equipment was adapted for use on virtually all AWACS aircraft. During Operation Desert Storm, one class of AWACS, the E-3 Sentry, flew more than 400 missions and logged more than 5,000 uninterrupted hours of on-station time in part because of the reliable nature of the ground servicing equipment, including the ZER-HVAC units.
DataPlex is proud to have been able to make such a worthwhile contribution for protecting advanced aircraft and spacecraft electronic systems.