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Is Conference Room Air Making Us Dumber?

nytimes.com

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Re: Is Conference Room Air Making Us Dumber?

#111

Post by castratikron »

Klathmon wrote: post #19
Mistletoe wrote: post #5

I own a CO2 monitor and it is shocking how high it can get in a house with two people just existing. 800 ppm or more. Outside air is 410. In a car with air on recirculate, it was getting to >1220 ppm, a level that impairs decision making and lowers brain function. I try to drive with air on fresh from now on. I don’t doubt the air in our conference room with 20 people gets super high in CO2 as the meeting goes on, an…

I picked up a CO2 monitor a while ago myself, and the biggest surprise was having it on in the morning in our bedroom with the doors closed. It was easily over 1000ppm IIRC. Ever since then I've made sure to set my AC system to run the "house fan" for 15 minutes or so every hour at night just to circulate the air in the house, and while the numbers went down significantly, anecdotally I swear that I wake up easier in…

I monitored the CO2 in my bedroom every second for three months and I found results similar to you. If I was sitting right next to the sensor in the evening it would go up to about 1900 ppm. Cracking open the window for an hour or so eventually brought things down to the 500ppm range.

What was interesting is how fast the ppm increases when someone enters the room. I would plot the data and see a blip on the graph when I entered. It was within seconds of entering.

Re: Is Conference Room Air Making Us Dumber?

#112

Post by segfaultbuserr »

w-m wrote: post #76

How are CO2 sensors built? Can you make them small and cheap enough to put in a phone, so I'd get a notification if the CO2 levels are rising?

> Can you make them small and cheap enough to put in a phone, so I'd get a notification if the CO2 levels are rising?

Yes! It's possible. But the air circulation inside a smartphone is limited and newer phones are completely sealed for waterproofing, so there are still some doubts.

> How are CO2 sensors built?

Based on my very limited experience on playing with electronics, I would say...

1. Previously, many CO2 sensors use an electrochemical process, the chemical cell in the sensor reacts with air, and outputs an analog voltage proportional to the gas concentration. They are large, have a distinct cylindrical shape similar to a microphone module, needs manual calibration, and common in the industry. For example, have a look at the datasheet of MG811 sensor, which mentioned how the chemistry works: https://sandboxelectronics.com/files/SEN-000007/MG811.pdf

2. NDIR sensors is another traditional option. Inside a large rectangular blackbox, it has an infrared LED and some electronics. Basically, you shoot a beam of infrared light though the air and detect it on the other end, and correlate your measurement with the gas concentration. NDIR is reasonably accuracy, very popular in the industry, and can detect particulate air pollutants, and many types of gas. As an example, take a look at the MH-Z16 datasheet: https://sandboxelectronics.com/wp-content/uploads/2018/08/Z1...

3. It's now possible to build an all-in-one digital gas sensor on a piece of semiconductor chip! Examples include:

* CCS811, it has an on-die sensor that detects VOCs and CO2 concentration, and even includes a microcontroller that speaks I2C. And it only costs 5.76 USD each per 1000 pieces. Datasheet: https://cdn.sparkfun.com/assets/learn_tutorials/1/4/3/CCS811...

All the three CO2 sensors I've mentioned are available on sale from Adafruit and Sparkfun for anyone who's interested to experiment with.

Re: Is Conference Room Air Making Us Dumber?

#114

Post by segfaultbuserr »

humblebee wrote: post #99
w-m wrote: post #76

How are CO2 sensors built? Can you make them small and cheap enough to put in a phone, so I'd get a notification if the CO2 levels are rising?

Most co2 sensors I've seen on Amazon are in the $100 range. I found some good information though[0], and the smallest form factor (CozIR-LP) retails at $109 [1]. [0] https://www.co2meter.com/blogs/news/6010192-how-does-an-ndir... [1] https://www.co2meter.com/products/cozir-lp-ambient-air-co2-s...

These modules are expensive because they are designed mainly for industrial applications, not for low-cost customer electronics.

Re: Is Conference Room Air Making Us Dumber?

#116

Post by roel_v »

Mistletoe wrote: post #5

I own a CO2 monitor and it is shocking how high it can get in a house with two people just existing. 800 ppm or more. Outside air is 410. In a car with air on recirculate, it was getting to >1220 ppm, a level that impairs decision making and lowers brain function. I try to drive with air on fresh from now on. I don’t doubt the air in our conference room with 20 people gets super high in CO2 as the meeting goes on, an…

"We are a group of scientists so it won’t be awkward or weird"

Story of my life right there

Re: Is Conference Room Air Making Us Dumber?

#117

Post by leereeves »

Klathmon wrote: post #43
Cthulhu_ wrote: post #41

Earlier quoted context omitted.

Helmets? That's interesting; I tend to open the visor a bit when at a stop, it gets really warm in there really fast. I know you shouldn't try to take off a helmet in case of an accident, but is opening the visor at least okay?

Yeah ever since I read that, I crack the visor or open it when i'm sitting still. And for opening the visor in accidents, I'm no expert but I believe it would be safe to do if you can do it without moving their head. IIRC the reason you don't want to take off the helmet is because you could strain their neck doing so. If you could move the visor without moving their head, it probably won't hurt, but at the same time…

Moving an unconscious person's head or neck can cause paralysis (if they have a spinal injury). Don't do it without training. In a city it's almost surely best just to wait for the EMTs.

Re: Is Conference Room Air Making Us Dumber?

#118

Post by scionthefly »

blattimwind wrote: post #14
Mistletoe wrote: post #5

I own a CO2 monitor and it is shocking how high it can get in a house with two people just existing. 800 ppm or more. Outside air is 410. In a car with air on recirculate, it was getting to >1220 ppm, a level that impairs decision making and lowers brain function. I try to drive with air on fresh from now on. I don’t doubt the air in our conference room with 20 people gets super high in CO2 as the meeting goes on, an…

School classrooms (20-30 people, 1-2 hours, closed windows, no ventilation) are probably worse than any conference room.

I ran a CO2 monitor in my classroom and found it exceeded 2000ppm on some occasions. Typically it would be 1200-1600. I discussed this with architects when building a new facility, and the new facility tests at I think the high levels before led to worse behavior and lower academic performance. Both seem generally better now.

Re: Is Conference Room Air Making Us Dumber?

#119

Post by faceplanted »

wishrider wrote: post #34

When I was a student I had a little room and one time I had a co2 monitor in my room for a few days. The monitor had 3 leds, green yellow and red. While sitting in the room for three consecutive hours (at the computer) the co2 would slowly rise from green to red and after opening the window for a while it was back at green. Now the interesting part is that I felt a strong correlation between tiredness and high co2 le…

Would definitely be an interesting longitudinal study to put a sensor in a set of classrooms, some of them with a your light system to suggest opening a window, and some of them not being told about the sensor, which would just log data as a control. You could compare grades and long term success in people in those classes.

Even in the short term it would be interesting to see if it affects any education metrics.

Re: Is Conference Room Air Making Us Dumber?

#120

Post by jandrese »

graeme wrote: post #45
maxlybbert wrote: post #40

Earlier quoted context omitted.

My senior year, the high school installed blowers in each classroom. We were told it was required by a new California law. I’m not sure it was an improvement: the blowers were noisy and made the classrooms much less comfortable (colder in winter, warmer in summer; it was an older school and the HVAC systems weren’t great). Teachers constantly talked about how they wanted to destroy the blowers. I seriously doubt grad…

Buildings used to be much draughtier, so it wasn't so much an issue. My landlord at my old place was always adding new insulation. Co2 levels there would get really high with windows shut. My new apartment has much lower ambient co2. Both were built 100 years ago. I think people also used to leave windows open a bit, even in winter. My (Canadian) grandma always did, and I hear it was the custom in Germany. Modern bui…

Maybe this is a tradeoff people need to consider when trying to reduce their wasted energy in buildings. Maybe try to do some kind of heat exchange in the air exchange?

I know of at least one case where a family was killed because they were using a laser cutter on wood indoors in a well sealed building and the small levels of CO released were able to build up to lethal levels.

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