Episode 667: Bradley Prezant, MBA, MSPH, CIH - Assessing Risk of Infection & Air Exchange – CO2 Pitfalls, SF6 Benefits

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Episode 667: Bradley Prezant, MBA, MSPH, CIH - Assessing Risk of Infection & Air Exchange – CO2 Pitfalls, SF6 Benefits

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Show Resources: Show Discussion:

12:03:37 From cliff zlotnik : trivia- what caused the death of 12,000 Australians in 1919?
12:03:53 From Paula Schenck : flue epidemic
12:04:50 From cliff zlotnik : Close enough Paula, (Spanish Flu) please send your contact info to czlotnik@cs.com
12:11:03 From Derrick A. Denis : We've used propylene glycol smoke with visible detection. We've used peppermint oil with olfactory detection. We've used CO2 emitted from people with meters. We've used CO2 introduced using dry ice with meters. We've never used Sulfur Hexafluoride.
12:13:39 From Host Computer : Just saw that Mike Lubliner from UW retired congrats Mike
12:19:46 From Derrick A. Denis : $65,000
12:30:51 From Paula Schenck : Practically thinking-your "far field modeling" may have the most public health value in suggesting where masks mandates are important or in extreme cases where closing indoor spaces would be reasonable until ventilation improvements are made. The "new normal" likely means we will need these tools for a very long time.
12:32:53 From Host Computer : Good point. There are a few other practical measures coming up in this interview. Particularly with respect to windows for ventilation.
12:35:42 From Host Computer : https://www.researchgate.net/publicatio ... TIMISATION
12:35:49 From Host Computer : https://www.researchgate.net/publicatio ... TIMISATION
12:36:15 From Host Computer : This is a great document. We will also have it on our website after the show
12:36:27 From Host Computer : We will talk more about it after halftime
12:41:15 From Host Computer : I should have asked more about using the flow hood and the pros and cons of that method. I will ask Brad to comment and put it in afterthoughts.iaqradio.com
12:55:20 From Paula Schenck : The problem is that "regulators" and building managers want a number to hang their hat on. I have resisted answering that question but it is difficult when so many just don't understand these nuances.
12:59:14 From Derrick A. Denis : Do you consider design occupancy? Sometimes we get the plans and see that the design occupancy is 25 people, but there are 33 people in the room. We don't need measurements at that point to suggest the system will not ventilate, cool or heat effectively.
13:01:04 From Host Computer : I found this part really interesting. Its obvious once you think about it but sometimes what's obvious to us is not obvious to those designing and maintaining buidings.
13:11:02 From Paula Schenck : Thank you. Very helpful discussion!
13:11:19 From Radio Joe : Thanks Paula
13:13:15 From Derrick A. Denis : GREAT GUEST!
13:13:52 From Brad Harr : Outstanding
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Re: Episode 667: Bradley Prezant, MBA, MSPH, CIH - Assessing Risk of Infection & Air Exchange – CO2 Pitfalls, SF6 Benefi

Post by CliffZ »

Another very informative IAQradio broadcast.

Congrats to Paula Schenck for being first to answer the IAQradio trivia question.

Brad Prezant is an advocate of the use of “Risk Calculator” occupant modeling used to predict risks of infection.

The volume of space determines the quantity of infection in air, higher ceiling heights are occupant protective.

David Bearg’s book “Indoor Air Quality & HVAC Systems introduced Brad to the concept of using tracer gas.

Tracer Gas is either a present or added substance used to track airflows indoors.

GREAT CASE STUDY: The story of air quality complaints, a de-pressurized below ground fan room, and sewer gas. Brad discussed a case study where tracer gas was used in a medical facility to determine the cause of odor and illness complaints. The building had an underground fan room. During construction, heavy equipment crushed sewer lines. Leaking sewage contaminated the ground and the high static pressure (3”-4”) in the fan room drew vapors from the soil through the porous concrete and circulated them within the building. They were able to make this determination by dropping tracer gas into the sewer system.

Ventilation Optimization AIRAH document link: https://www.airah.org.au/Content_Files/ ... chools.pdf

Z-Man signing off
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Re: Episode 667: Bradley Prezant, MBA, MSPH, CIH - Assessing Risk of Infection & Air Exchange – CO2 Pitfalls, SF6 Benefi

Post by RadioJoe »

It's always a pleasure talking to Brad Prezant. Upbeat and intelligent are just two words to describe him. What started out as a pretty technical show also included a bunch of practical information that can be implemented quickly.

I will be using some of the things learned today when we open a new gym at the Northwinds Lodge at Indian Lake. Higher ceilings and using windows and doors for better ventilation will be high on the list. We will also have a dedicated dehumidifier and possibly far UV. We should have one of the safest gyms in the area once we get everything implemented.

It's also great to see when people recognize those that have influenced their work. Brad points out several people he has great respect for.
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