Designing for Québec: Frost Management, Proper Sizing, and Real Comfort

Introduction

Heat pump systems designed for the North American climate must contend with extreme conditions: prolonged cold, rapid temperature fluctuations, high humidity levels, and significant thermal loads. At Willis, more than fifteen years of hands-on field experience have shaped a unique engineering approach focused on real-world performance rather than theoretical ratings. This fundamental difference guides every stage of development: mechanical design, control algorithms, frost management, material selection, and technical support for HVAC contractors.

Technical Section

The inverter compressors used by Willis allow for precise frequency modulation, reducing mechanical wear while ensuring energy delivery proportional to actual heating demand. Continuous analysis of subcooling and superheat—constantly recalculated—ensures system stability even when suction pressure drops in very cold climates. This stability is essential to prevent short cycling, a common cause of reduced efficiency and premature equipment failure.

Frost Management

Frost is one of the major challenges for any heat pump system. Willis units incorporate an intelligent defrost algorithm that activates only when real operating conditions require it. Unlike time-based systems, this technology reduces time spent in defrost by up to 27% while maintaining indoor comfort.

Field Analysis

Contractors working with Willis report a noticeable reduction in service calls related to winter capacity loss. This consistency is the result of a combination of factors: proper system sizing, clear documentation, direct technical support, rapid parts availability, and stable cold-climate performance.

Conclusion

The Willis philosophy is built on a balance between technical innovation, ease of installation, and proven reliability. For both professionals and homeowners, this approach delivers a durable, high-performance system truly adapted to the North American climate.