David Elfstrom π
@davidelfstrom.bsky.social
P.Eng, Energy management, measurement & verification. Toronto, Canada. Born 327ppm CO2. Climate Action & electrification; Safer infrastructure; cycling; air filtration & ventilation
The YT algorithm brought me this delight from 11 years ago. Perfect editing
Beastie Boys | So Whatβcha Want | Muppets Version
YouTube video by isthishowyougoviral
youtu.be
February 7, 2026 at 10:16 PM
The YT algorithm brought me this delight from 11 years ago. Perfect editing
Reposted by David Elfstrom π
fraggle rock implies the existence of fraggle jazz and fraggle rap
February 3, 2026 at 5:55 PM
fraggle rock implies the existence of fraggle jazz and fraggle rap
Tricksy little earthpigs, my precious!
February 2, 2026 at 6:03 PM
Tricksy little earthpigs, my precious!
A decade ago there was a Shopify account selling great TTC merch, some celebratory and some satiric. It was quickly shut down. bsky.app/profile/davi...
February 2, 2026 at 1:58 PM
A decade ago there was a Shopify account selling great TTC merch, some celebratory and some satiric. It was quickly shut down. bsky.app/profile/davi...
Thank you, College St is my commute! I've been taking the subway instead of college streetcar because so many vehicles keep parking over the rails.
February 2, 2026 at 12:05 AM
Thank you, College St is my commute! I've been taking the subway instead of college streetcar because so many vehicles keep parking over the rails.
On-street parking on Bloor St. has been clear of snow for six days while snow makes the bike lane unusable. Excess snow should be dumped in the on-street parking spots. Prioritize movement of people, not storage of private property on a public road.
Yes, we had a major snow event.
Yes, the city is triaging, and many sidewalks in particular still need work.
But it's been a week and arterial bikeways are remain unrideable and worse appear to be dumping grounds for snow-clearing.
What's the plan, Toronto?
www.torontotoday.ca/local/transp...
Yes, the city is triaging, and many sidewalks in particular still need work.
But it's been a week and arterial bikeways are remain unrideable and worse appear to be dumping grounds for snow-clearing.
What's the plan, Toronto?
www.torontotoday.ca/local/transp...
Toronto cyclists frustrated by snow-blocked bike lanes week after record storm
Biking advocate Michael Longfield of Cycle Toronto is calling on the city to communicate a clear plan for removing snow from bike lanes
www.torontotoday.ca
February 1, 2026 at 10:41 PM
On-street parking on Bloor St. has been clear of snow for six days while snow makes the bike lane unusable. Excess snow should be dumped in the on-street parking spots. Prioritize movement of people, not storage of private property on a public road.
Spoiler-free summary:
Alec Watson begins with very conservative assumptions to easily show the economics of renewable energy and goes on to dismantle the strongest whataboutisms. The impact of politics on energy starts an hour in, and Alec winds up and delivers precision, passionate, and contagious truth bombs. /2
You are being misled about renewable energy technology.
YouTube video by Technology Connections
www.youtube.com
February 1, 2026 at 7:03 PM
Spoiler-free summary:
No spoilers!
January 31, 2026 at 9:00 PM
No spoilers!
To continue with my longer Zone 2 ride, I added episode 7 of Star Wars: Andor season 1: "Announcement". It's right after the heist episode, and announces all of the ramifications of the heist, the retaliation of the Empire and the beginnings of the rebel uprising. Very fitting /3
January 31, 2026 at 8:25 PM
To continue with my longer Zone 2 ride, I added episode 7 of Star Wars: Andor season 1: "Announcement". It's right after the heist episode, and announces all of the ramifications of the heist, the retaliation of the Empire and the beginnings of the rebel uprising. Very fitting /3
Alec Watson begins with very conservative assumptions to easily show the economics of renewable energy and goes on to dismantle the strongest whataboutisms. The impact of politics on energy starts an hour in, and Alec winds up and delivers precision, passionate, and contagious truth bombs. /2
You are being misled about renewable energy technology.
YouTube video by Technology Connections
www.youtube.com
January 31, 2026 at 8:25 PM
Alec Watson begins with very conservative assumptions to easily show the economics of renewable energy and goes on to dismantle the strongest whataboutisms. The impact of politics on energy starts an hour in, and Alec winds up and delivers precision, passionate, and contagious truth bombs. /2
I allow myself to only watch movies/shows if I simultaneously do a Zone 2 indoor bike ride.
Today was different: I saw that @techconnectify.bsky.social had a new video out, checked out the duration, and knew I was in for a 1h 32 min treat. Tears welling up at the end.
Today was different: I saw that @techconnectify.bsky.social had a new video out, checked out the duration, and knew I was in for a 1h 32 min treat. Tears welling up at the end.
You are being misled about renewable energy technology.
YouTube video by Technology Connections
www.youtube.com
January 31, 2026 at 8:25 PM
I allow myself to only watch movies/shows if I simultaneously do a Zone 2 indoor bike ride.
Today was different: I saw that @techconnectify.bsky.social had a new video out, checked out the duration, and knew I was in for a 1h 32 min treat. Tears welling up at the end.
Today was different: I saw that @techconnectify.bsky.social had a new video out, checked out the duration, and knew I was in for a 1h 32 min treat. Tears welling up at the end.
On-street parking has been clear for a while. Those few spaces should be used for snow storage, removed from the sidewalks and bike lanes.
January 30, 2026 at 7:45 PM
On-street parking has been clear for a while. Those few spaces should be used for snow storage, removed from the sidewalks and bike lanes.
Reposted by David Elfstrom π
"If we already have good reason to believe a treatment works, randomizing people to a placebo means knowingly denying them benefit. Thatβs not science. Thatβs harm in the name of methodological purity."
This. 1000x.π₯
Going to forward to a local gang RCTing portable HEPA units. In hospital rooms.
This. 1000x.π₯
Going to forward to a local gang RCTing portable HEPA units. In hospital rooms.
January 30, 2026 at 3:41 AM
"If we already have good reason to believe a treatment works, randomizing people to a placebo means knowingly denying them benefit. Thatβs not science. Thatβs harm in the name of methodological purity."
This. 1000x.π₯
Going to forward to a local gang RCTing portable HEPA units. In hospital rooms.
This. 1000x.π₯
Going to forward to a local gang RCTing portable HEPA units. In hospital rooms.
On Tuesday morning while stumbling along Bloor St (the subway was down) it was really galling to see impassable bike lanes and to experience troublesome sidewalks, while the permanent on-street parking spots were clear (and occupied) Excess snow should be dumped in those spots!
January 28, 2026 at 7:37 PM
On Tuesday morning while stumbling along Bloor St (the subway was down) it was really galling to see impassable bike lanes and to experience troublesome sidewalks, while the permanent on-street parking spots were clear (and occupied) Excess snow should be dumped in those spots!
Roughly 10:05 pm every night now!
January 28, 2026 at 2:57 AM
Roughly 10:05 pm every night now!
Reposted by David Elfstrom π
This is really sad... we actually need to test and fix the environments we are living, working, and playing in...
cbc.ca/news/health/radon-gas-cancer-screenings-9.7058488
cbc.ca/news/health/radon-gas-cancer-screenings-9.7058488
A toxic gas was hiding inside his home for decades. It's radon, and scientists are tackling its deadly rise | CBC News
Radon gas, an invisible health threat that can build up in your home, is putting more Canadians at risk of deadly lung cancer. A national research team is using throwaway toenail clippings to find mar...
cbc.ca
January 27, 2026 at 2:53 AM
This is really sad... we actually need to test and fix the environments we are living, working, and playing in...
cbc.ca/news/health/radon-gas-cancer-screenings-9.7058488
cbc.ca/news/health/radon-gas-cancer-screenings-9.7058488
Well, more like lukewarm
January 27, 2026 at 2:13 AM
Well, more like lukewarm
Yes, not through solid materials in the way that moisture can travel, but through air cracks, driven by the stack effect (chimney effect). In some buildings pollutants from the underground parking garage can end up many stories above.
January 27, 2026 at 2:07 AM
Yes, not through solid materials in the way that moisture can travel, but through air cracks, driven by the stack effect (chimney effect). In some buildings pollutants from the underground parking garage can end up many stories above.
The Ken Soble Tower in Hamilton is an example of a truly deep energy retrofit.
Ken Soble Tower
The Ken Soble Tower Transformation is a ground-breaking project rehabilitating a post-war apartment tower in Hamilton, Ontario. The achieved goal meets Passive House standards to reduce greenhouse gas...
www.eraarch.ca
January 27, 2026 at 2:03 AM
The Ken Soble Tower in Hamilton is an example of a truly deep energy retrofit.
Wrap the building in a coat: Add an exterior insulation finishing system (EFIS) and replace the windows. A major undertaking. It's usually only done when the brick is failing.
January 27, 2026 at 1:46 AM
Wrap the building in a coat: Add an exterior insulation finishing system (EFIS) and replace the windows. A major undertaking. It's usually only done when the brick is failing.
For where the floors meet the wall, it's all concrete/masonry, no insulation, also known as a thermal bridge.
January 27, 2026 at 1:38 AM
For where the floors meet the wall, it's all concrete/masonry, no insulation, also known as a thermal bridge.
I took some thermal images of the building featured in this post by @lloydalter.bsky.social: lloydalter.substack.com/p/in-praise-...
ALT: Heat loss at street level podium glazing, and in the tower where each floor slab intersects the exterior wall. After sunset -10 C ambient.
ALT: Heat loss at street level podium glazing, and in the tower where each floor slab intersects the exterior wall. After sunset -10 C ambient.
January 27, 2026 at 1:30 AM
I took some thermal images of the building featured in this post by @lloydalter.bsky.social: lloydalter.substack.com/p/in-praise-...
ALT: Heat loss at street level podium glazing, and in the tower where each floor slab intersects the exterior wall. After sunset -10 C ambient.
ALT: Heat loss at street level podium glazing, and in the tower where each floor slab intersects the exterior wall. After sunset -10 C ambient.
Probably better off with two devices unless using a PC/mac
January 26, 2026 at 7:21 PM
Probably better off with two devices unless using a PC/mac
Thankfully it's a smart bike so it holds power even when my cadence changes. A few BPM difference though as I changed positions and found I was holding my breath!
January 26, 2026 at 4:10 PM
Thankfully it's a smart bike so it holds power even when my cadence changes. A few BPM difference though as I changed positions and found I was holding my breath!