What Does “Design Day” Really Mean?
August 12, 2021 By Luke Powell, WELL AP, LEED AP As I type this, the ambient (outdoor) temperatures are 95°F dry bulb and 79°F wet bulb here in Louisville, KY. Those conditions are above a “design day” for Louisville (94.0°/75.1°). The American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE) puts out […]
Ventilation In Schools – Be Careful What You Are Bringing In!
April 10, 2021 By Luke Powell, WELL AP, LEED AP I recently came across this study that was published March 27, 2021. The study came out of Spain and looked to assess air quality in classrooms after increasing ventilation as directed by public health officials. Ventilation conditions (carbon dioxide, CO2) and suspended particulate matter […]
Do Portable Air Cleaners Really Help?
March 16, 2021 By Luke Powell, WELL AP, LEED AP Last month, the CDC issued revised recommendations for mitigating the spread of COVID-19. Part of those recommendations included portable air cleaners that use high-efficiency particulate air (HEPA) filters to enhance air cleaning wherever possible. https://www.cdc.gov/coronavirus/2019-ncov/community/ventilation.html https://www.cdc.gov/coronavirus/2019-ncov/community/schools-childcare/ventilation.html Their “Ventilation in Schools and Childcare Programs” graphic even shows […]
OSHA Guidance on Mitigating and Preventing the Spread of COVID-19 in the Workplace
February 25, 2021 By Luke Powell, WELL AP, LEED AP You can read the full document from the Occupational Safety and Health Administration (OSHA), with all recommendations here: https://www.osha.gov/coronavirus/safework I want to focus on the “Improving Ventilation” portion. Despite what you may hear, both the CDC and ASHRAE have recommended making improvements to ventilation […]
ASHRAE Epidemic Task Force’s Aerosol Exposure Core Recommendations
On January 6, 2021, the ASHRAE (American Society of Heating, Refrigeration and Air Conditioning Engineers) Epidemic Task Force released new guidance to address control of airborne infectious aerosol exposure. An infectious aerosol is a suspension in air of fine particles or droplets containing pathogens such as the SARS-CoV-2 virus that can cause infections when inhaled. […]
Ventilation – Does Your Home Have It? Probably Not.
December 20, 2020 By Luke Powell, WELL AP, LEED AP Ventilation. A term that most people outside of the HVAC world rarely heard until a few months ago. As the COVID-19 pandemic escalated, and the CDC and WHO finally started to recognize airborne transmission, ventilation quickly became a buzz word. So why does ventilation […]
Aerosols, COVID-19 and HVAC
Luke Powell’s presentation to the Louisville ASHRAE Chapter on October 21, 2020 Webinar Recording: Louisville ASHRAE Oct. 2020 Meeting Notes PDF: Aerosols COVID-19 and HVAC – Notes from Louisville ASHRAE Presentation Side Deck: Aerosols, COVID-19 & HVAC – Slide Deck References: How can airborne transmission of COVID-19 indoors be minimised? https://www.sciencedirect.com/science/article/pii/S0160412020317876?via%3Dihub Aerosol and Surface Stability […]
Introducing WELL Building Standard Version 2
Yesterday (September 15, 2020) marked the official release of WELL v2. The WELL Building Standard™ version 2 (WELL v2™) is a vehicle for buildings and organizations to deliver more thoughtful and intentional spaces that enhance human health and well-being. The new version includes a set of strategies—backed by the latest scientific research—that aim to advance […]
The Case for Airborne Transmission of COVID-19
Droplets Fomites Aerosols Airborne What do all of these terms mean when it comes to the spread of COVID-19? Let’s look at definitions of each first. Droplets – Defined by the CDC and the WHO as projectiles that infect by impaction and fall quickly to the ground (often called “ballistic droplets”). Particles larger than ~300 […]
Ventilation in Schools
There has never been more focus on ventilation in school buildings. This leads to the obvious question – what do we actually know about ventilation in schools, and how important it is? Many studies use indoor CO2 to characterize ventilation, because the primary source in a school building is people breathing, and the outdoor concentration […]
