Every electrical system added to an aircraft increases the heat that must be managed, and Honeywell Aerospace says the job of air and thermal management systems has expanded well beyond cooling the cabin and cockpit. Cassie Matto, Honeywell’s director of offering management for thermal management systems, says cooling demand increasingly comes from radar, satellite communications, flight displays and onboard computing rather than passenger comfort alone. Those tradeoffs are most pronounced on battery-powered advanced air mobility platforms, where weight has a direct impact on performance. “Pound for pound, every little bit counts and makes a difference to their overall performance and range,” Matto said.

MOVING BEYOND BLEED AIR

Honeywell says earlier aircraft relied heavily on engine bleed air to power environmental control systems, while more-electric aircraft are expanding the use of electrically driven air and thermal management technologies, reducing reliance on bleed air and giving designers more flexibility over where cooling is delivered. Engineers must weigh where, and how much cooling is required against the weight and electrical power available, a challenge Honeywell says is compounded as every additional heat exchanger, compressor, duct and cooling line competes for limited space and electrical capacity onboard.

TREATING COOLING AS A DESIGN DECISION

Rather than optimising each system independently, Honeywell says engineers are increasingly considering electrical power, environmental control and thermal management together from the start of a programme, since decisions in one area affect performance and cooling capacity elsewhere on the aircraft. High-density cooling systems are becoming more relevant as aircraft carry more electronics in tighter spaces, and Honeywell says commercial, defence and advanced air mobility platforms each require tailored solutions rather than a single standard approach.