Zonefirst OAS Air Sensor

For veteran technicians managing dual fuel HVAC systems, the ZoneFirst OAS Air Sensor is a critical component for achieving precise balance point control. This outdoor air sensor is engineered specifically to integrate with ZoneFirst H32, H32P, and MDP3 control panels, providing real-time ambient temperature data to the fossil fuel heat pump logic. By utilizing a high-accuracy thermistor housed in a UV-stabilized polycarbonate enclosure, the OAS ensures the system transitions seamlessly between the compressor and the backup furnace based on the outdoor balance point (OBP) settings, typically adjustable from 5°F to 53°F. This transition is vital for preventing the heat pump from entering inefficient defrost cycles during extreme cold and optimizing overall refrigeration cycle performance. The sensor features a non-polarity sensitive 2-wire connection, simplifying field wiring with standard 18AWG jacketed cable, and its seamless aluminum tubing frame provides a thermal barrier for stable, reliable readings in environments ranging from -40°F to 140°F.

• Precise Dual Fuel Logic: Enables the ZoneFirst H32P control panel to automatically toggle between air-source heating and fossil fuel auxiliary heat.
• Rugged Environmental Protection: The UV-stabilized housing and aluminum probe construction prevent sensor drift and withstand harsh outdoor conditions.
• HVAC Zoning Compatibility: Optimized for MasterZone control systems and MDP3 panels, supporting up to 103 zones in expanded configurations.
• Simplified Field Installation: Non-polarity sensitive 24V AC wiring eliminates common connection errors during HVAC outdoor air sensor installation.
• Advanced System Efficiency: Eliminates the need for external mechanical thermostats or bulky dual fuel kits by using integrated panel logic.

How do I test the ZoneFirst OAS for accuracy?
To verify field performance, disconnect the sensor from the panel leads; at a room temperature of 75°F, the thermistor should provide a resistance reading of approximately 10.5K ohms.

Where is the optimal mounting location for the outdoor sensor?
For the most accurate heat pump balance point readings, mount the sensor on the North, East, or West side of the structure, ensuring it is shielded from direct sunlight and away from exhaust vents or snow accumulation zones.

Can I use this sensor with other zoning panel brands?
The OAS is specifically calibrated for ZoneFirst zoning system logic (H32, H32P, MDP3, and BMPlus series). Using it with non-compatible hardware may result in inaccurate temperature reporting.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.