HOTKREM Air Quality Monitor Indoor air Quality Monitor for Cars,Home,Office,Hotel etc (PM1.0,PM2.5,PM10)

Model "A1C-PM2.5+AQI+UPLOAD"When the wildfire smoke from Canada came down this summer 2023, this unit outside matched the AQI of about 150 from the AirNow dot gov site +/- 5%. The overall AQI is nice, but I really like that it includes the counts for six particle sizes on one screen. It responds to powdered drink mix, airing out my bedroom sheets and sweeping hard floors. The count of the smallest particles goes nuts--into five digits--when I fry (burn) eggs in butter. Nothing else comes close.I run an oversized HEPA filter in my room to clear allergens. When I open the door to the outside air, values rise. After I close the door, numbers drop as the filter clears the air. Sometimes I feel uncomfortable and look over to see that the AQI went over 50 (not "Good") for some reason.The humidity is significantly different from a TRIPLETT RHT313 electronic thermometer/hygrometer I have. Not sure which unit is accurate. This one has a fan drawing air towards the unit. Temperature seems reasonable.There's a screen with date and time of day that's always wrong. There's supposed to be software to set this and download data, but I haven't tracked it down. Honestly, for these fun little products, it would be best if the manufacturer just published the communications protocol because anyone could write a little script and give it away on the internet for anyone to find. Remember Hayes modems? If we could control those, we can surely communicate with this in 2023.Love it.

Across the brands, this may be about the best, but it is limited to the sensor technology. 2.5u is not small enough to sense the dangerous micro dust that KILLS you in a woodshop. Temp and RH were better than a lot of inexpensive units. Problem is, an accurate 2.5u runs about $20,000 and to measure .03u you need collection media and a laboratory. If this things says "bad" get the heck out of there!Add says 1u reading, but as far as I can tell, sensor only has a 10u and < 2.5 outputs. No 1u output.

This is a nice air quality meter. Data display is clear and in testing, it certainly responds to things like opening the door to a wood-burning stove. A few downsides though:1. There is no ISO, ASTM, or similar certification or calibration for this unit. In using this device you're relying on the skill of the programmers/EE's that designed the device. Probably not suitable for any situation where you NEED to know the real AQI or PM2.5 level.2. There's no data export feature. It would be interesting for science fair, smart home, weather monitoring, or control applications to be able to export single measurements or measurement files with repeated PM2.5 levels. This data could be sent via USB (serial) or SD logging card.3. There's an on-board "real-time-clock" chip, but it isn't clear how to set the time on the RTC. This is a drag, but I guess it doesn't matter since the data logging feature doesn't work.

I order the Hotkrem air quality monitor because we burn wood for our main heat during the winter season. I was most curious about our indoor air quality as a result. The unit provides air temp, air humidity and air quality readings constantly. I am relieved at finding the the air quality is always in the good level even though we burn wood. The only issue is that occasionally the unit seems to freeze. I simply unplug it and plug it back in allowing it to "reboot" if you will. It's only happened a few times over a several month period. Otherwise, I love the unit.

It is fun to play with. I live in an apartment and when monitoring my utility closet the detector would stay in the yellow/red zone most of the time. This is because of holes and gaps between apartments allow a little air to circulate between units. I notice an odor occasionally and now I know where it is coming from. The rest of my apartment is always in the green unless I light an incense or cook something wild.I spent a week of a two week holiday remodeling the small utility closet. Now not only does it look awesome I also sealed the unnecessary gap. The monitor now stays in the green.Very happy with the monitor and plan to purchase another — it looks so cool too