Overview
ISO 15714:2019 specifies a laboratory method to evaluate the UV dose delivered to airborne microorganisms passing through in-duct ultraviolet germicidal irradiation (UVGI) devices installed in HVAC systems. The standard defines test-rig configuration, microbial surrogates, test procedures, data calculations and reporting formats so that the disinfection capacity of different in-duct UVGI products can be compared reliably. Where a microorganism’s UV susceptibility is known, the measured UV dose can be used to calculate expected inactivation rates.
Key topics and technical requirements
- Test rig configuration: square ducts with 0.6 m inner side length; upstream and downstream duct lengths of 2.0 m and a UVGI device mounting section of 1.0 m. Duct walls constructed of galvanized steel or aluminium with 50–60% reflectivity. Components include blower, dampers, HEPA filters, injection port and sampling ports.
- Model microorganisms: the standard lists representative test strains (for example Serratia marcescens, Bacillus subtilis, Cladosporium sphaerospermum) and defines preparation, cultivation and suspension procedures to produce airborne challenge aerosols.
- Test procedure: determination of airflow, temperature and humidity; controlled generation of airborne microbes; sampling with and without UV irradiation; culture and enumeration to obtain survival ratios.
- Data analysis: calculation of inactivation rate (N/N0), derivation of average UV dose from measured inactivation, and use of the UV dose‑response relationship (ln(N/N0) = k · D) where k is the microorganism’s susceptibility constant.
- Reporting and evaluation: standardized result reporting, repeat tests across multiple airflow rates, rig qualification and safety/environmental controls (references ISO 15858 for UV‑C safety).
Practical applications
- Product testing labs and manufacturers: to certify and benchmark in-duct UVGI devices for air disinfection performance.
- HVAC designers and building engineers: to compare devices and estimate in-duct disinfection effectiveness under specified airflow conditions.
- Public health and facility managers: to inform selection of UVGI solutions for hospitals, schools, offices and other indoor environments.
- Regulators and standards bodies: to adopt consistent test methods for claims about UV air‑disinfection performance.
Related standards
- ISO 15858 - UV‑C devices: safety information and permissible human exposure (normative reference in ISO 15714).
- ISO 29464 and other air‑cleaning/particle terminology standards (for related definitions).
Keywords: ISO 15714:2019, UV dose, UVGI, in-duct UVGI, HVAC, airborne microorganisms, test rig, UV susceptibility, air disinfection, UV‑C.