Keep Healthcare Healthy Enhance Healthcare Spaces with Standard 241 and Airfl ow Measurement ASHRAE Standard 241, Control of Infectious Aerosols, provides airfl ow rates that will dilute and clean the air in buildings in normal and infection risk management mode (IRMM). With an EBTRON air measurement device, you can easily switch from normal to IRMM, maintain rates during all operating states, and validate clean air rates (VECAi). Measure and control outdoor air ventilation rates in normal or IRMM to verify dilution rates and ensure energy is not wasted. Measure airfl ow through In-duct Air Cleaning Systems to validate clean airfl ow rates. Measure the supply airfl ow to determine VECAi delivered and minimum air change requirements. Track and control airfl ow rate diff erentials (pressurization fl ow) of supply, return, and exhaust to ensure that healthcare spaces remain properly pressurized to limit the spread of airborne pathogens.