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Just picked one up, having issues if anyone is familiar and could help. The co2 reading has just been stuck at 402 for a couple hours. Not moved at all, and pm2.5 is showing 6, which is kind of shockingly low considering my a/c filter is completely covered in cat dander and the evaporation coil behind it is nearly completely clogged with god knows what and I have no air purifiers. Doesnt seem right

Hello, my partner and I are looking to install a ductless? ERV to help with ventilation and our house is old and very small and does not lend itself to ducting. For various reasons, we are looking at a ductless ERV as a solution to helping with ventilation as well as our moisture problem (we also have a dehumidifier but don't want an HRV to make things worse). We live where it gets pretty cold in the winter. (Maine). we also have budgetary concerns. we've also had to be careful during the pandemic so we've been putting this off for a while.

Has anyone here tried the Vents-US Twinfresh Comfo or Expert? what do you think?

https://shop.vents-us.com/products/twinfresh-expert-ra1-50-2-ductless-erv?srsltid=AfmBOoqsfrT4J6Jvo29ORKvvvXQCd59UefwlzWgJgX5H6S7sP8iJUThx

Any recommendations on an outdoor monitor that would pick up pollutants / air quality that result from burning please?

I'm dealing with a neighboring property that is burning and polluting the air on our property with a toxic burning smell. It's bad enough to where you can go out to check your mail and come back smelling like you've been sitting in a campfire all night.

The local city ordinance officials are on my side that this is "a thing" and there are noxious fumes laws in our jurisdiction, but proving a smell is hard and they dont burn during business hours so it's complicated. Tried a direct neighborly approach, but the property owner is dismissive about the problem. Want to take some readings so that I can show hard data to the city officials and hopefully get this resolved through official channels.

Willing to spend a few hundred bucks if I have to. Thanks in advance for any recommendations.

EDIT: Thanks everyone for the helpful suggestions. Going with the outdoor AirGradient.

I've always had a Dyson air purifier in baby's nursery. But I hadn't downloaded the app and monitored the air quality until recently. After I downloaded the app, I noticed that the VOC had always been at level 4 at night when the door and windows were closed. I've been trying to find the source of VOC by removing one thing at a time from baby's room. Today we finally decided to peel off the peel and stick wallpaper we put on a wall. And the VOC went back to zero with door and windows closed. So my questions are:

1. How bad is VOC level 4 on a Dyson? (Air quality reading is fair.)

2. I asked the company in Australia that produced the wallpaper. They said they used UV ink that is Greenguard Gold Certified. So I assume the VOC comes from the adhesive. The wallpaper was installed and had been aired out in the room for more than a year now. How is it still emitting VOC?

3. Baby has been sleeping in the room for almost a year. How harmful could this VOC from the wallpaper be?

It's very hard to find a straight answer. Obviously it can vary, but there has to be some ballpark number.

Hi,

See the attached image. I have these two sensors, both of which are supposed to be quite good. The Inkbird always reads 80 - 140 higher than the Airgradient for co2 levels.

In the image, I had both of these next to an open window for over an hour to try to get the co2 down as low as possible indoors.

I've had the Inkbird for about 2 weeks and used it in different places in my house. I've had the Airgradient set up for a few days. I thought it could be a calibration issue with the Inkbird, I put that outside yesterday for an hour and did the manual calibration. It still seems to be the same, it always shows higher.

When I have the Airgradient in a room without any people, the co2 level sometimes goes down to below 400.

When I had the Inkbird outside yesterday for an hour the lowest that it went down to was 430.

It makes me think that the Airgradient could be reading too low and the Inkbird is reading too high.

I have the Airgradient set to the EPA formula, I don't know how to calibrate it. The Inkbird is set on the manual calibration.

Any ideas?

https://preview.redd.it/irdnwd8gxvxd1.jpg?width=4080&format=pjpg&auto=webp&s=3fddd51e9fd2979bae5fac6ef1c4aca3955336db

We bought and moved into a new home in April. This house was built in 1971 and a month ago we got rid of all the old blown-in insulation and replaced with bats of insulation (fiberglass and Rockwool). Installers sealed crevices in the attic prior to placing the insulation down. However, we have many canless recessed lights they couldn’t seal around. The insulation was only added to the attic and we have a crawl space under the house. Since the insulation I’ve noticed my sinuses are more swollen and pressure in my ear has increased. My son had 2 headaches. I don’t know if this is a personal health issue, coincidental, or sick building syndrome. I’m trying to figure out if it’s me or the house.

Is it possible the new insulation has somehow made my house too tight and the air pressure is somehow now imbalanced? Does fresh air have no way to come in and stale air has nowhere to exit? We used an AirThings monitor and saw varying numbers of hi and low CO2 with no one in the room. No VOC issues. We used barometers to compare inside vs. outside air pressure —indoors is on par with the pressure outside. On occasion indoor pressure is slightly higher. Trying to find some guidance on how to even check and rule out the air pressure quality and issues. What profession does this?

I have a pet cage in my room. Would using a small extractor fan to direct air flow through a hose to the air purifier inlet do a better job than just letting the air purifier do its job? The extractor fan would also help better ventilate the (partially closed) pet cage.

https://preview.redd.it/vbryfdnxpsxd1.png?width=2528&format=png&auto=webp&s=8da410158c14cef2fd8b5c56a79790a4496aca9d

Just installed monitor yesterday.

Noticed spike this AM while cooking breakfast. Around 9. The obvious one in the middle of the chart. Also noticed gas flame was orangey. Had National Grid over to look at the flame. They also tested for CO and whatever other gases (not particulates) their meters test for (which does not incl particulates). Came up negative for everything.

National Grid guy suggested our humidifier could be the reason for the orange flame and that we should not worry about that at all.

Nonetheless, based on the data... something bad is happening when I use my stove, right?

Hi all. Recently purchased a Co2 with NDIR sensor. I live in a condo/apartment near busy road, I tried measuring the co2 levels on different areas in my home.

When windows are open, co2 reads around 600ppm.

Bedroom: When windows are closed, reads around 1200ppm.

Bedroom: When windows closed, airconditioning ON, reads around 1,500-1700ppm overnight.

Is this normal? I am unable to let the windows open overnight since I live in a busy road with hot climate.

Thanks in advance

My place of employment has a visible smog of coolant and aluminum dust. The air quality monitors read an aqi of 300 on average. Osha has been contacted about this and the company responded with false results of air quality readings. Osha now denies to investigate any claim for ventilation issues. I need this job. I feel stuck. I breathe this air for 12 hours a day 6 days a week. What can I do to bring this to someone's attention to fix this? Or how can I prevent myself from exposure/damage while working here?

Hi, I live in Belgium and when i see all this footage of industry and cars exhausting more and more pollution into the atmosphere, it honestly gives me anxiety. How much more air pollution can our atmosphere take before breathing would become seriously problematic? I live in Ghent, Belgium in case that makes a difference however isn't it so that increase in air pollution elsewhere can still affect breathing where you live since air travels. Actually my biggest concern if Trump gets re-elected is that he will give the oil industry free rain to do whatever they want even more.. and china and india are also still increasing fossil fuels.. I hope you know what i am trying to say.. like how much can our atmosphere really take before we reach a crucial point and how regional is this? Hope somebody can explain how worried i should be. Thanks.

So I just bought an air quality sensor sensirion SEN55-SDN-T, it came without a cable (I want to connect it to an esp32). They use this weird connector: JST-GHR 6 pin. I have trouble finding a cable. I've found a couple of cheap cables on aliexpress but they take 1 month to arrive. I have found really few websites that sell this cables but the prices are high and the shipment too (we are talking about 20€ for one cable).

I thought of replacing the connector, so I partially opened the housing of the SEN55 and discovered that the pcb is secured to the housing with melted plastic so it would be a pain to remove.

How am I supposed to use this thing? Will a JST-GH (non-R) cable work?

https://preview.redd.it/2p6v2yi45ixd1.png?width=2772&format=png&auto=webp&s=7bfb608568540f893c178c0c3b988972b969a3eb

This is what I got using my Temtop M10+ Indoor Air Quality Monitor for a month sitting on my nightstand. I feel like the CO2 levels are too high and might be an air quality concern. I've been running my AC here in NC so I typically do keep the windows shut but the ceiling fan on. The doors and windows are not sealed very well and certainly some ventilation is occurring there. But maybe I just need to be more diligent about opening some windows when I'm home? AQI and PM2.5 seem good, not sure what the spikes are. Any other thoughts? Thanks for looking.

Hi,

I have been monitoring air quality in one area in the north of Spain (Asturias) for over a year to choose well where to relocate and live a long, healthy life. :)

I have been using Plume and Google Maps (it provides information on air quality as well) but the values vary from each other, e.g. one app would show that the air quality is very good in one particular town and the other would show moderate air quality.

I couldn't find a ton of information regarding how do these apps measure the air quality, Google just states that it picks the closest station to you. There's also the bit that the value that you are getting might not be the real value, but the value between the two or more closest stations.

Could you give me some pointers to dig deeper? In your opinion, which is the most reliable source to measure air quality in Europe / Spain?

Thanks in advance and have a pollution free day.

I've been having air quality and breathing issues for sometime. There is often some kind of odor inside the house. Yesterday I decided to run some experiments using an air quality monitor.

Typically the Formaldehyde (HCHO) level / VOC is about 80-90 ug/m3 and 400 ug/m3 respectively.

After airing the house for a while, HCHO/VOC dropped to about 20/110 (ug/m3) 

Then turned off AC and closed windows. It seemed to jump really quickly over about 30-40 mins to about 50/240

After turning on AC and waiting over the same amount of time, it increased but seems at a slower rate. Not sure if because of air cleanup/filtering or the cooling effect of the AC but increased slightly to 60/310

Now I've been suspecting that there is some leak from the attic to my home. Often leaving the house for a while and coming back it smells like attic. Checking up in the Attic, I saw a reding of about 70/320 then as I come down from the attic, it's pretty much the same in the house. 

So not sure what the conclusion is . Possibly

• AC doesn't make things significantly worse
• Air quality in Attic is same as inside house. Does that mean there is a leak somewhere ?!
• Is the AC exonerated ? (since things didn't get significantly worse after turning on) or AC caused issues are only observable after running for a longer period of no ventilation because .... negative pressure buildup , duct leakage, etc.

Hope that made sense to someone out there.

I know there are some prescribed burns happening south of where I am . I dont understand what the odd smell is though.. and the bay area air mgmt saids the PM is not much over 50 yet I can tell something is really off about the outside air quality.

Purple Air Map has lot of high VOC readings.

any thoughts on what could be causing this ?

https://map.purpleair.com/air-quality-experimental-voc?opt=%2F1%2Fi%2Flp%2Fa10%2Fp600%2FcC0#9.24/37.8155/-122.0901

Due to conditions beyond my control, the air pollution level in my city has risen to 60, and now it consistently shows 150-170. The Pm2.5 concentration is 10-11 times higher. The city is constantly shrouded in white haze, smog. It stinks of gasoline outside, and today, when it started to stink of burnt plastic, the index showed 200. Every time I go outside, I feel a sore throat, a desire to cough, and eye irritation. Due to global warming, the wind rose has changed, and instead of winds and rain, there is absolutely nothing.

So, please tell me how I can minimize the harm? I don’t like feeling irritation in my trachea, etc. Every time I go outside, I feel depressed, or something. I wear a regular medical mask, but it doesn’t help much. Local authorities don't care, and neither do car drivers)

Sorry, maybe this is too personal, but I just need to pour out my soul, to understand that it's not only me who cares. The average person doesn't care! They walk with their children, strollers) Until they announce a danger on Facebook, they won't move at all. Indifference, ehhh...

I'm in a college dorm building with no ventilation whatsoever, except for the ground floor. We can't open any windows and don't have any fans. The best option for ventilation is cracking windows in the communal bathrooms which doesn't help much. Is there any way to get fresh air in the dorm rooms? Or is there at least a way to reduce CO2 levels in the air? We don't get much sunlight so plants are not an option.Thanks

I recently bought this TVOC monitor. Then I emailed their support for the formula it uses to calculate air quality, they nicely provided this:

Aqara TVOC formula

ChatGPT reckons they are assuming temperature is always 25°C and pressure is always 1 ATM, with the full formula being:

ChatGPT TVOC formula

My question for you: how accurate is the sensor, given our home temperature ranges from 16-24°C throughout the day?

Does anyone on here have any contacts or is themselves a contact with Washington university in saint louis? I'm looking to get some more information about their collection site in east saint Louis.

I have a factory next door that has started commercially spraying agricultural equipment, they have a spray booth that goes through "filters" and is then extracted outside. It blows right into my yard and house, I'm deeply concerned about hwat might be in it. I tried self-research but got so confused. I'm writing to look for recommendations on hardware, ideally with real time monitoring that I can put on my fence in front of the extractor to monitor how bad the fumes are that are coming out.

I'm highly technical so DIY or getting my hands dirty stuff won't put me off installation/setup.

Can anyone recommend hardware that can detect the bad stuff, I know about VOC, but also anything else, it needs to be fairly accurate too as I plan to make a formal complaint. Ideally under 500 would be great but I'm happy to spend for peace of mind if needed.

Hi everyone,

I would highly appreciate it if you could share your expert knowledge

I live in an apartment in a multifamily house. The room size is 30 square meters. About 1 meter from my entrance door there is another apartment and the person smokes in the evening.

I use an air purifier, and the particulate matter concentration right next to the door near the bottom part of the door is about 100 micrograms per meter cube, which is a dangerous concentration. When I open the door, the PM concentration is 250. About 1 meter inside from the door, the PM concentration is 20, and right next to me, it is 5.

Regarding the Total volatile organic compounds, the level is about 1.1 milligram per meter cube when he smokes and goes to 0.5 mg after 3 to 4 hours when he stops smoking.

A small fan can not create enough positive pressure inside a room. But when I used a fan (20 watts) near the slightly opened window (6 cm wide opening with a length of 1.5 meters), the PM concentration at the bottom of the door decreased from 100 to 10, a 90 percent reduction. The window is located in another room. If I turn off the fan, the PM concentration comes back to about 100 micrograms per meter cube even if I open the window, so there is positive pressure created by the fan. Am I correct, or am I missing something?

I am happy with the effect, but now the winter has come, and I cannot open the window the whole day since it causes mold. I am planning to buy a carbon filter and fan with about 150-meter cube airflow. Furthermore, I am worried that since it created negative pressure, my room will be filled with the PM and VOC from the smoker's room. Do you guys have any advice for me ? Thank you very much for reading.

Hello!

I am building a DIY air quality monitor as a hobby project. I bought a few CO2 and PM sensors that are used in well-known monitors like PurpleAir, Air Gradient etc. I have CO2 sensors from two different companies. Their values are quite off, one is showing 800 ppm and the other 1200 ppm. Similar story with the PM sensors.

Is it possible to rent a professional co2 and PM monitors that have more accurate sensors? I am just curious, want to know which sensor is closest to the professional monitor. What do you think? If yes, please let me know some reputable brands.