Sources of anomalously high particulate matter emissions indoors on a hot day - Page 1
Forum section: electronics / general

author: I wanted a rude username
author_rank: Frequent Contributor
timestamp: December 21, 2019, 02:28:55 am
content: Yesterday we had a balmy 43.5 °C day here in Melbourne.By the afternoon, it was about 30 °C in my apartment, with windows closed (quite well weatherproofed) and no air conditioning. I wasn't cooking, and the only electrical appliances operating were the fridge and several computers plus network gear.At this time, the indoor particulate reading was extraordinarily high: PM2.5 was about 40, and the particulate count for PM0.3 was about 12,000. Normal figures here are more like 4 and 500, respectively. Running an air cleaner (supposedly "true HEPA" rated) for a few hours got these numbers down by a factor of five, but only opening the windows late in the evening cleared the air.The apartment is ancient and hasn't seen a lick of paint in over a decade, no new carpets or furniture, all the electrical stuff that was running is a few years old, and there's no gas supply.What could be the sources of these particulates?Edit: John B and Habropoda point out that the particulate levels were astronomical yesterday due to the NSW bushfires. Graph in Habropoda's post below.

author: jadew
author_rank: Frequent Contributor
timestamp: December 21, 2019, 02:46:10 am
content: Not having done measurements myself I can only guess... but it's possible you're losing more skin than usual or humidity is down on this particular day.

author: Red Squirrel
author_rank: Super Contributor
timestamp: December 21, 2019, 03:12:27 am
content: Those are crazy hot temps. It could be VOCs being released from various things like furniture, paint, etc. Just a guess though, not sure if that would even register?Do you have lot of fans running to try to cope with it? Could also just be kicking up dust more that is already on surfaces.

author: I wanted a rude username
author_rank: Frequent Contributor
timestamp: December 21, 2019, 03:24:36 am
content: Quote from: Red Squirrel on December 21, 2019, 03:12:27 amNo fans whatsoever except those in the computers (and the tiny one in the particulate meter), and later the air cleaner.It's weird, for sure. The concentration is ludicrous. Just now I fried some food in butter (admittedly at a relatively low power) and only measured PM2.5 of 12 µg/m3and a PM0.3 count of 1,500 ... directly above the frypan.

author: John B
author_rank: Frequent Contributor
timestamp: December 21, 2019, 03:28:46 am
content: Perhaps you've noticed the entire east coast of Australia is on fire. Even Melbourne is getting the smoke. I can literally see the haze in my room, and my lungs feel like I've smoked a cigarette.

author: John B
author_rank: Frequent Contributor
timestamp: December 21, 2019, 03:31:49 am
content: Also don't put too much faith in closing the windows. Unless you've had the same air supply for days, the smoke is getting everywhere. It's a major concern in hospitals and care facilities at the moment.

author: I wanted a rude username
author_rank: Frequent Contributor
timestamp: December 21, 2019, 03:43:37 am
content: PM2.5 is about 3 at the moment. Have you opened your windows since yesterday? Maybe you're experiencing the results of the same effect.The particulate levels with the windows open both in the morning and subsequent evening were an order of magnitude lower, and I've not seen high readings throughout the past weeks that NSW has been on fire.

author: Habropoda
author_rank: Regular Contributor
timestamp: December 21, 2019, 03:48:51 am
content: What are you using to test your air? Purpleair.com has a half dozen sensors in the Melbourne area and you can get various 2.5 and 0.3 readings with charts. The 0.3 readings were around 20,000 for yesterday and are much reduced today.

author: Habropoda
author_rank: Regular Contributor
timestamp: December 21, 2019, 03:53:06 am
content: Here is one station.

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: December 21, 2019, 03:54:13 am
content: Quote from: I wanted a rude username on December 21, 2019, 02:28:55 amLay off the dodgy vindaloos.

author: I wanted a rude username
author_rank: Frequent Contributor
timestamp: December 21, 2019, 03:58:20 am
content: Quote from: Habropoda on December 21, 2019, 03:53:06 amWow. That would be it, then. Thanks for the tip!Quote from: Ed.Kloonk on December 21, 2019, 03:54:13 amI'll stop farting when you stop ranting. I.e. never.

author: I wanted a rude username
author_rank: Frequent Contributor
timestamp: December 21, 2019, 04:23:56 am
content: Do you remember when TLC stood for The Learning Channel?Anyway, it's a relief that this isn't some unidentified off-gassing. And browsing the PurpleAir map really puts things in perspective ... not just the obvious candidates like India, butcheck out the Bay Area and LA!

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: December 21, 2019, 04:28:31 am
content: Quote from: I wanted a rude username on December 21, 2019, 04:23:56 amWell, I learned something today.I wanted a rude usernameis no bloody good in shared accoms.

author: Habropoda
author_rank: Regular Contributor
timestamp: December 21, 2019, 05:47:55 pm
content: Quote from: I wanted a rude username on December 21, 2019, 04:23:56 amYep, everybody points at China and India where the air can get really bad but there are not many angels in the rest of the world. Air pollution is a global problem.

author: Red Squirrel
author_rank: Super Contributor
timestamp: December 21, 2019, 08:20:27 pm
content: Quote from: John B on December 21, 2019, 03:28:46 amReminds me of the Timmins 9 fire years back, no where near the scale of what is going on in California, the Amazon, Australia etc but it was quite eerie when the wind went the right way and our city was in a dark blanket of smoke. You could really smell it in the air, and we had to get maintenance to go to all our buildings (telecom switching offices) to close all the outside intakes. For us it only lasted like a day though. The fire itself lasted long but the smoke was not hitting us directly. Can't imagine going through that for weeks or months non stop. Especially for people that may already have existing respiratory issues.Speaking of Fires we don't really hear about the one in the Amazon anymore, is that still going?