P.Eng, Energy management, measurement & verification. Toronto, Canada. Born 327ppm CO2. Climate Action & electrification; Safer infrastructure; cycling; air filtration & ventilationhttps://bsky.app/profile/davidelfstrom.bsky.socialhttps://bsky.app/profile/davidelfstrom.bsky.social/post/3mr4sagiodk2yThere's still six Tuesdays before August 30. That's six T.A.C.O. Tuesday opportunities.21 Jul 2026 02:47 +0000at://did:plc:3a43qvblimqkecprththymuj/app.bsky.feed.post/3mr4sagiodk2yhttps://bsky.app/profile/davidelfstrom.bsky.social/post/3mqz2ry5e7223Unusual failure mode to have a vehicle split in half. Is that intentional, or a consequence of other design choices? https://www.yahoo.com/news/us/articles/cybertruck-split-half-moving-truck-113535255.html19 Jul 2026 15:10 +0000at://did:plc:3a43qvblimqkecprththymuj/app.bsky.feed.post/3mqz2ry5e7223https://bsky.app/profile/davidelfstrom.bsky.social/post/3mqrqbal74k2dA Redditor put together some instructions on on how to make an optimized 1-filter air cleaner using a box fan from my experimentation several years ago. It's in a Google drive folder here: https://drive.google.com/drive/folders/14kSJg5O6i-AByKOKgirb2vmTsnZSoZv-16 Jul 2026 17:13 +0000at://did:plc:3a43qvblimqkecprththymuj/app.bsky.feed.post/3mqrqbal74k2dhttps://bsky.app/profile/davidelfstrom.bsky.social/post/3mqrbjxq5xk2qWorking outdoors? Child at outdoor day camp? Anyone outside for 6 hours today in Southern Ontario will be effectively smoking three cigarettes during that time. More if you're active. Twelve cigarettes over a full day. https://map.purpleair.com/air-quality-cigarettes-per-day?opt=%2F1%2Flp%2Fa10%2Fp604800%2FcC0#9.23/43.6074/-79.478316 Jul 2026 12:49 +0000at://did:plc:3a43qvblimqkecprththymuj/app.bsky.feed.post/3mqrbjxq5xk2qhttps://bsky.app/profile/davidelfstrom.bsky.social/post/3mqplosm2dk22Brantford is now at 500 μg/m3!! GET INSIDE!15 Jul 2026 20:46 +0000at://did:plc:3a43qvblimqkecprththymuj/app.bsky.feed.post/3mqplosm2dk22https://bsky.app/profile/davidelfstrom.bsky.social/post/3mqpgogokh226Sarnia is unaffected by wildfires as the Minister makes his speech about sovereign energy pipelines there. Meanwhile, Kitchener's air is downright hazardous. [contains quote post or other embedded content]15 Jul 2026 19:16 +0000at://did:plc:3a43qvblimqkecprththymuj/app.bsky.feed.post/3mqpgogokh226https://bsky.app/profile/davidelfstrom.bsky.social/post/3mqpfjodq5225LOL https://www.ft.com/content/3a023b95-66c3-41e1-b0ce-df752a49954115 Jul 2026 18:55 +0000at://did:plc:3a43qvblimqkecprththymuj/app.bsky.feed.post/3mqpfjodq5225https://bsky.app/profile/davidelfstrom.bsky.social/post/3mqpe4ufkpk23Brantford has the worst air quality of all Ontario Ministry of Environment stations right now at 220 μg/m3 Wear an N95 or equivalent mask there!15 Jul 2026 18:30 +0000at://did:plc:3a43qvblimqkecprththymuj/app.bsky.feed.post/3mqpe4ufkpk23https://bsky.app/profile/davidelfstrom.bsky.social/post/3mqp7og7fts2vForest fire smoke in Ontario has cut air temperature 4-5°C than forecast, greatly reducing electricity demand today. You can see the areas with clear sky in Norfolk County near Lake Erie are around 32°C while Toronto is 28°C. Normally Toronto is one or two degrees warmer.15 Jul 2026 17:11 +0000at://did:plc:3a43qvblimqkecprththymuj/app.bsky.feed.post/3mqp7og7fts2vhttps://bsky.app/profile/davidelfstrom.bsky.social/post/3mqoy7zauzc2iReminder that ASHRAE has a page dedicated to protecting building occupants from wildfire smoke. https://www.ashrae.org/technical-resources/wildfire-response-resources15 Jul 2026 14:57 +0000at://did:plc:3a43qvblimqkecprththymuj/app.bsky.feed.post/3mqoy7zauzc2ihttps://bsky.app/profile/davidelfstrom.bsky.social/post/3mqowuzzhpk2bThe definitive government source for ground level pollutant measurements in Ontario is down, presumably due to high traffic volume. https://www.airqualityontario.com/history/pollutant.php?stationid=31129&pol_code=12415 Jul 2026 14:33 +0000at://did:plc:3a43qvblimqkecprththymuj/app.bsky.feed.post/3mqowuzzhpk2bhttps://bsky.app/profile/davidelfstrom.bsky.social/post/3mqnnl5pvu22vHey Toronto area forest fire followers and air quality nerds, there's a new data set for local PM10, PM2.5, and CO measurements at U of T sites, using QuantAQ sensors: https://tame.physics.utoronto.ca/surface-aq-data/ /115 Jul 2026 02:14 +0000at://did:plc:3a43qvblimqkecprththymuj/app.bsky.feed.post/3mqnnl5pvu22vhttps://bsky.app/profile/davidelfstrom.bsky.social/post/3mqn2e7a7gs2hCanada's NWT is 🔥 firesmoke.ca14 Jul 2026 20:30 +0000at://did:plc:3a43qvblimqkecprththymuj/app.bsky.feed.post/3mqn2e7a7gs2hhttps://bsky.app/profile/davidelfstrom.bsky.social/post/3mqmwm7epss2dThat was fast! Pedantry isn't necessarily bad. My work here is done 👍 [contains quote post or other embedded content]14 Jul 2026 19:23 +0000at://did:plc:3a43qvblimqkecprththymuj/app.bsky.feed.post/3mqmwm7epss2dhttps://bsky.app/profile/davidelfstrom.bsky.social/post/3mqmkcanpk22bDespite most of solar power generation in Ontario being hidden to IESO, the control room can still see the impact of weather (such as clouds) moving over populated areas with distributed solar PV generation. If you get an opportunity to tour the control room, do so! Very impressive. [contains quote post or other embedded content]14 Jul 2026 15:43 +0000at://did:plc:3a43qvblimqkecprththymuj/app.bsky.feed.post/3mqmkcanpk22bhttps://bsky.app/profile/davidelfstrom.bsky.social/post/3mqm43wgxmc2iGood morning Ontario gridwatchers on the hottest day of the year. Let's see how this plays out. /114 Jul 2026 11:29 +0000at://did:plc:3a43qvblimqkecprththymuj/app.bsky.feed.post/3mqm43wgxmc2ihttps://bsky.app/profile/davidelfstrom.bsky.social/post/3mqknycpnns2gOpened this up expecting to see Northfield Drive in Waterloo, and wasn't disappointed https://bsky.app/profile/davidelfstrom.bsky.social/post/3mlgzdy3kx22u [contains quote post or other embedded content]13 Jul 2026 21:43 +0000at://did:plc:3a43qvblimqkecprththymuj/app.bsky.feed.post/3mqknycpnns2ghttps://bsky.app/profile/davidelfstrom.bsky.social/post/3mqczgeseb222I pictured a modern art installation when reading my daughter's packing list10 Jul 2026 20:47 +0000at://did:plc:3a43qvblimqkecprththymuj/app.bsky.feed.post/3mqczgeseb222https://bsky.app/profile/davidelfstrom.bsky.social/post/3mpz5og5f5c2eBuild clean water pipelines, not oil pipelines! [contains quote post or other embedded content]06 Jul 2026 22:36 +0000at://did:plc:3a43qvblimqkecprththymuj/app.bsky.feed.post/3mpz5og5f5c2ehttps://bsky.app/profile/davidelfstrom.bsky.social/post/3mpwz5adn6c2mClearly, Canada prioritizes public finding of infrastructure for oil private profit over public funding to deliver potable water to First Nations communities for public health06 Jul 2026 02:10 +0000at://did:plc:3a43qvblimqkecprththymuj/app.bsky.feed.post/3mpwz5adn6c2m