ISO 5222-1:2023

Overview

ISO 5222-1:2023 - "Heat recovery ventilators and energy recovery ventilators - Testing and calculating methods for seasonal performance factor - Part 1" specifies test and calculation methods for the sensible heating recovery seasonal performance factor (F_sh) of heat recovery ventilators (HRV) covered by ISO 16494-1. The standard defines test conditions, procedures and calculation steps used for marking, comparison and certification of HRV sensible heating performance, using the rating conditions in ISO 16494-1 and the default outdoor temperature bins in Annex B.

Key topics and technical requirements

• Scope and relationship with ISO 16494-1: Applies to HRV sensible heating recovery metrics defined in ISO 16494-1:2022.
• Standard test conditions (T5/T6/T7): Specifies three reference test conditions (e.g., T5 = 2 °C outdoor / 21 °C indoor, T6 = 5 °C / 20 °C, T7 = 7 °C / 20 °C) for evaluating heating-mode performance and selecting the most representative condition for a given region.
• Test methods: Procedures for measuring gross sensible heating effectiveness (ε_sh), airflow, static pressure and system power under standard conditions and application climate bins.
• Bypass ventilation and energy-saving stages: Defines how to determine the bypass outdoor temperature (T_b), verify bypass function, and measure power input when bypass or staged fan control is used.
• Calculations: Step-by-step methods for:
  • Gross sensible heating effectiveness,
  • Sensible heating coefficient of energy for ducted and unducted ventilators,
  • Seasonal sensible heating capacity (E_sh) and seasonal power input (P_in,E),
  • Final seasonal performance factor F_sh (ratio of seasonal recovered sensible heat plus moving-air power value to total HRV electricity input).
• Additional requirements: Frost temperature determination, outdoor temperature bin distributions (Annex B), test reporting template and normative annexes for specific calculations (Annexes C, D, E, F).

Practical applications

• Product labeling, certification and marketing of HRV sensible heating performance.
• Independent testing laboratories use the test procedures and reporting templates to verify manufacturer claims.
• Manufacturers and R&D teams apply the standard to design and optimize HRV controls (bypass, fan staging) for improved seasonal performance.
• HVAC specifiers, energy auditors and building designers use F_sh values for system selection, energy modelling and comparing HRV options for cold-climate heating efficiency.
• Regulators and certification bodies adopt the method for standardized performance comparisons and compliance programs.

Related standards

• ISO 16494-1:2022 - Method of test for performance; provides metrics and definitions used by ISO 5222-1.
• Refer to the broader ISO 5222 series for additional parts covering other seasonal performance aspects.

Keywords: ISO 5222-1:2023, heat recovery ventilators, HRV, seasonal performance factor, sensible heating recovery, testing methods, ISO 16494-1, bypass ventilation, gross effectiveness, temperature bins.