{"id":1513,"date":"2021-05-14T14:40:49","date_gmt":"2021-05-14T18:40:49","guid":{"rendered":"https:\/\/drsmith.blog.yorku.ca\/?p=1513"},"modified":"2021-11-05T10:03:57","modified_gmt":"2021-11-05T14:03:57","slug":"fighting-covid-with-ventilation","status":"publish","type":"post","link":"https:\/\/www.yorku.ca\/professor\/drsmith\/2021\/05\/14\/fighting-covid-with-ventilation\/","title":{"rendered":"Fighting COVID with Ventilation"},"content":{"rendered":"

Introduction<\/h2>\n

It's May, 14, 2021 and the consensus is that COVID is airborne, that the characteristics of aerosols play a significant role in how it spreads and infects. \u00a0This is distinct from the outdated assumption that it is spread primarily through droplets and\/or surface contact (foamites).<\/p>\n

\"Carbon<\/a>Summary: Add CO2 Sensors to our Classrooms & Offices to verify healthy ventilation<\/h5>\n

I am advocating for the addition of CO2 sensors to all classrooms and offices in our schools. \u00a0Carbon Dioxide (CO2) measurement is commonly used by ventilation experts to determine the \"freshness\" of air. \u00a0More on this below.<\/p>\n

\"Twitter<\/a>

Source: https:\/\/twitter.com\/DFisman\/status\/1394273559472742405<\/p><\/div>\n

\"Letter:<\/a>

Excerpt from a letter<\/a> to Prime Minister Boris Johnson.<\/p><\/div>\n

\"Schools<\/a><\/h2>\n

Actions to Take in our Schools<\/h2>\n

Beyond distancing, masking and vaccination, we need to focus on airflow<\/strong> in the indoor spaces where people congregate: schools, offices, factories, distribution centres, etc. \u00a0Here I'm going to focus on school settings<\/strong>, whether at the elementary\/secondary or post-secondary.<\/p>\n

\"Thread<\/a>

https:\/\/twitter.com\/DavidElfstrom\/status\/1298001341747548160<\/a><\/p><\/div>\n

The reason we need to focus on airflow is that it is clear that there will be a non-negligible number of people<\/a> entering our schools who will either refuse to or cannot mask, distance or vaccinate. \u00a0Some may do so for sincere and truthful reasons, while others may hide or lie about their status or motivations. Regardless, verifying the COVID status of individuals will likely be impossible or impractical. \u00a0 So we must examine passive methods for minimizing the threat of COVID in these indoor environments. \u00a0Ventilation is perhaps the best candidate for this as it is unintrusive and universally applicable using mundane, proven, off-the-shelf technologies and techniques, as described in this interview<\/a> and associated Twitter thread<\/a>.<\/p>\n

\"Ventilation<\/a>Ventilation Improvements<\/h4>\n

Anybody that has been in a typical Canadian primary or secondary school in the middle of June knows how terrible the ventilation is. \u00a0While adding stand-alone fans and air filters in the classroom was a good ad-hoc approach in 2020 when we were coming to grips with the reality of COVID, it is no longer acceptable as the only way to improve ventilation.<\/p>\n

Properly designed and installed HVAC (Heating Ventilation and Cooling) systems, capable of exchanging \"dirty\" air for fresh, outside air is necessary. \u00a0Nothing short of this is acceptable if our goal is to reopen our schools -- and therefore our economies -- in September 2021.<\/p>\n

But installation of HVAC is not sufficient. \u00a0We need to monitor, in real time, the status of the air in our classrooms to ensure that when the ventilation fails we can be alerted to that fact and then act to keep our children and schools staff safe.<\/p>\n

Therefore, we need to measure the quality of the air in our classrooms.<\/p>\n

Ventilation Verification: CO2 Sensors<\/h4>\n

I am advocating for the addition of CO2 sensors to all classrooms and offices in our schools. \u00a0Carbon Dioxide (CO2) measurement is commonly used by ventilation experts to determine the \"freshness\" of air. \u00a0The consensus is that a level of CO2 between 400 and 800 ppm (parts per million) is the threshold for acceptable fresh air (sources: 1<\/a>, 2<\/a>, 3<\/a>, 4<\/a>, 5<\/a>).<\/p>\n

CO2 sensors are inexpensive, easy to install and operate. \u00a0Many look like the thermostats that we see in homes, schools and offices. \u00a0There are many sources of CO2 sensors, including:\"\"<\/a><\/p>\n