LETTERS P = 1 - e-A /Q (1) Based on available literature results, P is plotted against Q (Figure 1), and the data are fi tted with Equation 1 to yield A = 0.8054 h-1, with a very low correlation coeffi cient of 0.4621. From Figure 1 it can be seen that the values of P deviate appreciably from Equation 1 for Q less than 5 ach. Very few updated data exist for the novel coronavirus SARS-CoV-2, especially for the more infectious mutant coronavirus strains. A value of 6 ach adopted in many indoor places including restaurants led to many challenges, particularly from the catering industry with respect to normal business operation. Keeping the ventilation requirements of 6 ach minimum should be further justifi ed. As shown in Figure 1, it appears diffi cult to justify this requirement. Ventilation requirements for buildings should be reviewed7 by including the indoor airfl ow pattern for developing ventilation codes. Local air speeds and turbulence are the key factors affecting virus transmission Trying to Meet VRF Demands? There's a Loop for That! Introducing the VRF Metraloop thermal expansion joint, the latest in expertly engineered products from Metrafl ex. The VRF Metraloop has been specifi cally designed to handle the demanding conditions of VRF systems. Rated for 700 PSI @ 300°F Features the Metrafl ex Exclusive Copper to Stainless Steel Conversion Fitting FV Requires Minimal Guiding & Anchoring Rated for Full Vacuum ed for Full Vacuum TheVRF Contact Metrafl ex or Visit Online to Learn More! sales@metrafl ex.com| 800.621.4347 | www.Metrafl ex.com/VRF The Metrafl ex Company © 2021 J U LY 2 0 2 1 ashrae.org ASHRAE JOURNAL 9 0.1 0.8 0.6 0.4 0.2 Figure 1 P vs. Q. and can be predicted by computational fl uid dynamics (CFD). Numerical simulations can be performed to examine the transport mechanism, particle path and a suggested control strategy for reducing airborne infectious agents. CFD is now rather mature and in general cheaper than other methods. Correlation relations among the key macroscopic design parameters could then be obtained. 5 10 Q (ach) 3; 4; 5; 6 Fitted Curve With A = 0.8054 h -1 15 20 25 Phttp://www.Metraflex.com/VRF http://www.ashrae.org