All Caeli systems employ closed-circuit loops that recycle exhaled breath by scrubbing out CO₂ and replenishing O₂. This allows continuous breathing without atmospheric exchange, which is crucial for efficiency (oxygen conservation). We use advanced soda lime scrubbers with compression technology to maximize CO₂ absorption efficiency and extend canister life. Our scrubbers are also air-cooled to manage the exothermic reaction heat, improving comfort and safety.

In hybrid mode, our systems function as high-end PAPRs – drawing ambient air through CBRN-rated filters with a battery-powered blower. The integration is seamless: when PAPR mode is active, the blower maintains positive pressure in the breathing circuit to keep contaminants out. This design required an innovative pneumatic selector valve and control algorithm to transition between modes without interrupting the air supply. The result is a smooth switch that users can perform at will, even under duress, to greatly extend operating time.

Traditional rebreathers often force the user to breathe against spring-loaded bags, causing strain and fatigue. The CRUSOE series eliminates this burden with sensor-controlled dual blowers that actively assist inhalation and exhalation, creating a natural breathing rhythm even under exertion. At the same time, the system maintains constant positive pressure in the loop, preventing inward leaks of contaminants and ensuring safety in CBRN or toxic environments.

Together, assistive breathing and positive pressure deliver both operator comfort and uncompromising protection in the harshest conditions.

The CRUSOE series features a hot-swappable scrubber and oxygen cylinder system, allowing operators to extend missions well beyond standard endurance limits. With consumables replaced in minutes, teams can maintain uninterrupted breathing support in the field without withdrawing from the mission.

This design not only reduces logistical constraints but ensures continuous survivability for special operations, CBRN response, and long-duration rescue scenarios where every second counts.

Our design philosophy is to meet or exceed military and emergency standards. That means designing for extremes – extreme heat, cold, pressure, and contamination. For instance, all our systems are rated for -30°C cold start and operation in toxic industrial chemicals. We rigorously test against MIL-STD environmental conditions. 

Our rebreathers also incorporate integrated mask defogging, ensuring operators maintain clear visibility even in the harshest conditions. Additionally, we are pursuing NIOSH and NFPA certifications for relevant models to ensure compliance with civilian firefighter and industrial safety standards. Our commitment is that if a human can physically be in an environment to perform a job, our equipment will function and keep them safe and breathing while they are there.

The cooling principle of all CRUSOE systems rely on FCA²F (Forced Convection Ambient Air Flow), maintaining breathing oxygen at a stable temperature of approximately 32 °C (89.6 °F).

Caeli’s advanced cooling system is engineered to maintain operator comfort and system reliability under extreme conditions. By eliminating the need for ice packs or pre-mission chilling, it ensures consistent airflow temperatures throughout extended operations. This design reduces logistical burden, prevents regulator freeze, and protects operators from heat stress — whether in confined subterranean environments, high-exertion CBRN response, or long-duration tactical missions.

Most Caeli rebreathers are electronically controlled: onboard processors monitor O₂ levels, CO₂, pressure, and temperature. They automatically adjust O₂ injection rates and blower speeds to optimize the breathing mix and minimize work-of-breathing.

Our digital HUDs or displays provide the operator with critical alerts (e.g., scrubber end-of-life, low oxygen), allowing issues to be addressed before they become problems.