Episode 706: Jie Zhao, PhD - Head of Delos Labs & Executive Vice President at Delos - Keeping Our Buildings and Homes a

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Episode 706: Jie Zhao, PhD - Head of Delos Labs & Executive Vice President at Delos - Keeping Our Buildings and Homes a

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Show Resources: Show Discussion:

12:05:24 From cliff zlotnik : trivia, name the inventor of the first personal protective mask incorporating a charcoal based filter which removed more harmful gases than previous masks?
12:05:53 From Ralph Froehlich : Lewis Haslett
12:06:30 From cliff zlotnik : sorry not the inventor we were looking forward
12:06:31 From Ralph Froehlich : John stenhouse
12:07:09 From cliff zlotnik : correct Ralph, please send your contact info to czlotnik@cs.com
12:12:21 From Ralph Froehlich : Didn’t “making our buildings more airtight” lead us into our current IAQ problems after buildings were made more airtight in response to the energy crisis of 1973?
12:15:19 From Ralph Froehlich : Are you proposing better outdoor air pollution controls?
12:17:01 From Ralph Froehlich : Ozone is so reactive that indoor levels are typically much lower than outside concentrations. However, the reaction products in the indoor air may be more hazardous.
12:24:37 From Jonathan Faith : https://www.sciencedirect.com/science/article/abs/pii/S1011134423001094?via%3Dihub
12:35:12 From Ralph Froehlich : Cooling people is the key for heat stress management, but can introduce additional hazards. Legionella has been recognized as a hazard associated with misting systems in grocery produce areas.
12:39:45 From aonder : Cooling of our indoor environment starts with humidity control.
12:53:31 From Ralph Froehlich : What do you recommend for measurable indoor air quality parameters (CO,
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Re: Episode 706: Jie Zhao, PhD - Head of Delos Labs & Executive Vice President at Delos - Keeping Our Buildings and Home

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Show Number: 706

Jie Zhao, PhD
Head of Delos Labs & Executive Vice President at Delos
Keeping Our Buildings and Homes a Safe Oasis

Dr. Zhao is the Head of Delos Labs and an Executive Vice President at Delos. Delos is a wellness, real estate and technology company headquartered in New York City. As the creator of the WELL Building Standard, Delos develops products, programs and solutions that transform our environments into vehicles for health, well-being, performance, and resilience. Jie leads the research team to support product innovations and market strategies. He is also a lecturer in the Weitzman School of Design at the University of Pennsylvania. His research focuses on Human-building Interactions, including total building performance, occupant behavior in buildings, sensing and controls in buildings, health, comfort, and productivity of building occupants, as well as building energy efficiency and sustainability. Jie received his PhD in Building Performance and Diagnostics from Carnegie Mellon University.

This week we welcomed back Jie Zhao, PhD Head of Delos Labs and VP at Delos for a show on Keeping our buildings and homes a safe oasis. With heat extremes, wildfires, hurricanes, heavy rains, train derailments, Ozone action days and other atypical environmental hazards becoming more frequent it’s important that our buildings be prepared to provide a safe oasis.

Nuggets mined from today’s episode:

Radio Joe is working on the AIHA committee producing a guideline for IEPs dealing with atypical environmental hazards.

Wildfires and IEQ? Wildfires create immense quantities of PM 2.5. Short term human exposure to PM 2.5 particles is known to cause respiratory discomfort and irritation. Short term exposure to PM 2.5 is also known to trigger asthma. In longer term exposure PM 2.5 particles enter the blood stream, heart and cardiovascular system and cause heart and cardiovascular disease and other health problems. PM 2.5 is the #1 environmental risk health factor. PM 2.5 from Canadian wildfires is crossing the border and carried deep into the US. The number of wildfires worldwide is increasing due to global warming and forestry factors.

Wildfire preparation, resistance, and remediation? Airtight buildings are more wildfire resistant. Buildings can prepare for wildfires by sealing exterior cracks and crevices to prevent wildfires residues from getting indoors. It’s recommended that HVAC filters be upgraded to MERV 13 or better. HVAC filters need to be changed routinely. Placement of standalone air-cleaners in occupied spaces, and use of low cost sensors (or better) and air monitoring equipment are highly recommended. Weather Apps on smartphones show weather patterns. Be aware, be prepared. Airnow.gov

Does tightening buildings for energy efficiency cause IEQ problems? We’ve learned from the past that; air-tightening buildings for energy efficiency can cause IEQ problems and “sick buildings” when fresh air is reduced. The importance of fresh air is well known and understood. Well designed HVAC system dilute CO² and effectively capture particulate. Operable windows in low traffic areas can provide fresh air.

Ozone? Ozone is hard to remove from indoor environments. High ozone levels are often transportation related. In theory, sorption filters can remove some ozone. Photocatalytic oxidizers can breakdown ozone through very complex chemical reactions. Molecules from ozone reactions can form new chemical compounds when molecules from chemical reactions reassemble. Ozone is an indicator proxy of th end result of chemical reactions.

Pittsburgh, PA is one of the top ten worst cities for PM 2.5.

UV lights? Germicidal ultraviolet lights were widely used during COVID. 222 Nano UV light is used to sanitize entire rooms. 254 Nano UV lights installed on upper sanitize the air. Oxidation molecules break apart and reassemble to form sulfur dioxide, nitrogen dioxide and nitrogen monoxide. LED bulbs can be used. When the phosphor wears off of some bulbs; the UV bandwidth changes.

Heat Extremes? Due to the high percentage of US properties that are air-conditioned; the US has more and better resistance to heat extremes than much of the rest of the world (e.g. Europe, Asia and Middle East). We can prepare better for heat extremes by designing and buildings which are airtight, have good insulation, incorporate external shading, blackout curtains, which mitigate solar heat gain.

Thermal comfort? The human body’s thermal sensation differs for air and surface temperatures. Air movement changes the sensation. Air of the same temperature feels better when it blows on us. Fans blowing on us increase evaporation creating a cooling sensation. High humidity reduces thermal comfort, maintaining the indoors at 40%-60% RH improves comfort. Most heat pumps gave a dehumidification function.

Biophilic building design? The term biophilic, is a psychology term. Bringing nature indoors is known to increase human comfort, productivity and happiness. Dense building materials such as wood, clay, adobe help modulate RH indoors. Many studies demonstrate that biophilic effect is real.
Visual- closer to nature, wood, bamboo, plants, fake plants (plastic plants may emit VOCs)
Audio- sounds of birds, waterfalls, crackling fire, ocean, bubbling brooks, etc.
Olfactory- Controversial as aromas contain VOCs. Nor all VOCs are bad, it depends how they are produced. Naturally extracted oils are preferred. Use warmers or wood reeds to diffuse fragrant oils into the air.
• Do not put fragrance oils in humidifiers, as this application has not been adequately studied.
• Do not use fragrant candles.
• Do not ingest fragrant oils.

Leafy plants as air cleaners? Leafy plants have been oversold as air cleaners. Indoor plant walls have been studied for their ability to remove VOCs, results show the results are negligible. Plants assist in mental health.
• Keep plants out of bedrooms. Plants produce CO² at night.


• ASHRAE’s Control of Infectious Aerosols Standard is a significant achievement. It raises awareness and provides guidance and solutions.

• Equivalent Air Changes (E-ACH)- ASHRAE “…based on the concept that within limits ventilation, filtration, and air cleaners can be deployed flexibly to achieve exposure reduction goals subject to constraints that may include comfort, energy use, and costs.” According to Dr. Zhao, firms with interna; systems are using the term E-ACH and creating confusion in the market place.

• Current projects- Delos Labs is monitoring Air Quality Standards, Setting Benchmarks and Baselines, Raising awareness of problems. Baselining is the first step for meaningful improvement.

• Low cost sensors- accuracy is less important than practicality. Raising awareness is more important. Sensors with alarms or visual indicators red, yellow, green are preferred over sensors that just provide a number.

Z-Man signing off

Trivia- Name the inventor of the first protective mask containing a charcoal=based filter which removed more harmful gases than previous masks?

Answer: John Stenhouse, 1854

Answered by:
Ralph A. Froehlich, CIH, CSP, QEP
Helix Environmental, Inc.
1 Elizabeth Place, Suite 160H
Dayton, Ohio 45417
(937) 776-8435 cell
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Re: Episode 706: Jie Zhao, PhD - Head of Delos Labs & Executive Vice President at Delos - Keeping Our Buildings and Home

Post by RadioJoe »

Thank you Dr. Zhao. Great discussion on how buildings can be a safe oasis from atypical environmental hazards; wildfires, chemical spills, heat, O2. The heat topic and buildings is one we will need to focus on more. It's becoming a huge issue that has not been talked about enough.

Heat kills more Americans every year than any other weather-related disaster. Each year, an average of more than 700 people die from heat and more than 9,000 people are hospitalized nationally due to heat, according to the Centers for Disease Control and Prevention
https://news.yahoo.com/finance/news/t-a ... 03010.html
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