Purmo OZC 4.0

Purmo OZC is a professional building energy and load calculation tool developed by SANKOM Sp. z o.o. It helps HVAC engineers, designers, and energy auditors accurately determine room-by-room and whole-building heating needs, size equipment, and prepare clear, compliance-ready documentation. With an intuitive interface and robust calculation engine, Purmo OZC streamlines the path from concept to specification, supporting reliable design decisions and efficient system selection—especially for hydronic heating solutions.

Key capabilities:

• Peak heat load calculations at room, zone, and building levels for precise emitter and plant sizing
• Seasonal energy demand assessment with detailed heat balance (transmission, ventilation, internal and solar gains)
• Flexible modeling of building envelope elements, including ground-contact components and thermal bridges
• Ventilation and infiltration inputs, with support for heat recovery systems
• Built-in libraries for climate data, materials, and constructions, all customizable to project needs
• Clear, configurable reports and summaries suitable for submittals and regulatory documentation
• Scenario comparison to evaluate design alternatives and optimization strategies
• Workflow designed to assist in selecting appropriate heating components from the Purmo portfolio

Purmo OZC enables faster, more transparent design workflows and defensible sizing decisions. It is well suited for new construction and retrofit projects across residential and commercial buildings, providing the rigor and clarity required for modern HVAC design.

Purmo OZC is developed by SANKOM Sp. z o.o.. The most popular versions of this product among our users are: 3.0 and 4.0. The name of the program executable file is OZC.EXE.