Independent ASHRAE 241 Standard Test for Bioaerosols and Air Cleaning Technologies
Airmid Healthgroup specialises in the ASHRAE 241 standard test, providing manufacturers, developers, and regulators with independent, high-quality data on air cleaning system performance.
ASHRAE 241 Standard Test Method: Key Requirements
ISO 17025 Compliant Testing
Airmid Healthgroup operates under ISO/IEC 17025 accreditation principles, ensuring rigorous quality control.
Biosafety Standards
All bioaerosol testing follows CDC/NIH Biosafety in Microbiological and Biomedical Laboratories (BMBL) guidelines, using safe, EPA/ASHRAE-approved surrogates like MS2 bacteriophage.
Advanced Bioaerosol Chambers
Testing takes place in precisely controlled bioaerosol exposure chambers, designed to replicate real-world indoor air conditions.
Standardised Environmental Parameters
Temperature (70–75°F), humidity (50–60%), and sampling protocols meet ASHRAE 241 specifications.
Triplicate Sample Plating
ASHRAE 241 requires at least three replicates per test condition (system OFF vs. system ON), ensuring statistical reliability.
How We Conduct ASHRAE 241 Testing
- Chamber Preparation: The bioaerosol chamber is thoroughly disinfected before testing.
- Microbial Aerosolisation: A known concentration of test microorganisms is aerosolised into the chamber under controlled conditions.
- Baseline Air Sampling: Initial air samples are collected to determine microbial concentration before the air cleaning system is activated.
- Air Cleaning System Activation: The test system is turned on, and air samples are taken at key time points (e.g., 5, 10, 15, and 30 minutes).
- Sample Analysis & Enumeration: Samples are analysed to measure microbial reduction and determine the ASHRAE 241 equivalent clean airflow rate (V-ACS).
- Control Runs: Identical tests are performed without the air cleaning system to establish baseline natural decay rates.
Get Your Air Cleaning System ASHRAE 241 Tested
Ensure your air cleaning system meets ASHRAE 241 performance standards with Airmid Healthgroup’s expert testing services.
Industry Leadership and Collaboration
- Members of the ASHRAE 241 review process, ASHRAE 185, and the Environmental Health Committee
- Members of ISO air cleaner committees
- Members of IEC air cleaner committees
- Working closely with AHAM on AC-5 testing
- Endorsed by patient organisations such as the Asthma & Allergy Foundation of America (AAFA) and ECARF
- An accredited laboratory for the Verified Healthier Air program
- Strong network of leading academics, medical schools, and applied research centres with high-impact publications
- www.iAIR.Institute, a 501(c)(6) in Washington, DC
- Working on the ARPA-H BREATHE project
Why Choose the iAIR Group?
- Proven Expertise in Bioaerosol Testing: With a strong history in aerobiology research, we offer deep scientific expertise in airborne pathogen studies.
- Trusted by Industry Leaders: We work with HVAC manufacturers, building developers, and regulatory agencies to validate air cleaning technologies.
- Independent & Accredited: As an ISO 17025-accredited laboratory, our testing meets the highest standards of accuracy and reproducibility.
- GLP-based projects
- Aerobiology Infection Control Chambers and Allergen Exposure Chambers (AECs)
- Bio-safety Level 2 testing, including flu virus, bacteria, and mould testing
- Pre-clinical and clinical studies, CRO network
- Facility for digital twins, computational fluid dynamics, and AI mathematical models to enhance real-time chamber testing
ASHRAE 241 Test Standard: Ensuring Healthier Indoor Environments
ASHRAE (the American Society of Heating, Refrigerating, and Air-Conditioning Engineers) develops industry standards that shape the performance of HVAC and air cleaning systems. ASHRAE Standard 241 establishes a test method for biological aerosol removal and defines the minimum equivalent clean air requirements to reduce airborne disease transmission in indoor environments.
Get Your Air Cleaning System ASHRAE 241 Tested
Contact Airmid Healthgroup to discuss ASHRAE 241 testing requirements for your air cleaning technology and receive a tailored quote.
Frequently Asked Questions
Related Tests to ASHRAE 241 Testing and Test Standard
- What Is AHAM AC-5 Testing
- Test Method for UV-C Disinfection in Air-Handling Units and Air Ducts
- ANSI/AHAM AC-1 2020; Method for Measuring Performance of Portable Household Electric Room Air Cleaners
Related Resources to ASHRAE 241 Testing
- ASHRAE Standard 241: Control of Infectious Aerosols – Understanding its Impact
- Reflections on the ASHRAE Winter Meeting: Infectious Aerosols, Standard 241, and Healthy Buildings
- Understanding MERV, HEPA, and ASHRAE Standards
Related External Links
- ASHRAE Publishes Standard 241, Control of Infectious Aerosols
- ASHRAE Standard 241-2023; Control of Infectious Aerosols
- Purchase: ASHRAE Standard 241, Control of Infectious Aerosols
Related Aerobiology Testing Services
- Overview of Aerobiology Chamber Testing
- Testing Services to the ASHRAE 241 Standard
- AHAM AC-5 Testing
- ANSI/AHAM AC-1 2020
- ASHRAE 185.1-2020
- Custom Bioaerosol Protocols
Tag Words
ECAi, ASHRAE 241 test, bioaerosol testing, airborne pathogens, infectious aerosols, MS2 bacteriophage, aerobiology, infection control chambers, CADR, AHAM AC1, AC5, air cleaning technologies.
This page was last updated April 22nd 2026 by Oliver Dsa.
