David Elfstrom

@davidelfstrom.bsky.social

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P.Eng, Energy management, measurement & verification. Stratford, ON Canada
Born @ 327ppm CO2
Safer infrastructure; Corsi-Rosenthal Boxes; building ventilation
web: elfstrom.com

Posts Replies Media

All aboard the #Caturday train!

Tonight I introduced 10y old daughter to Star Wars episode IV (the 1997 remaster in 4K with its unnecessary additions). She liked it, was bored with the long trench run at the climax. Then we watched the book+record adaption I had as a kid.

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David Elfstrom

Why the Bicycle with Two Chains Might Just Be the Best Bike at Eurobike 2024 velo.outsideonline.c...

Why the Bicycle with Two Chains Might Just Be the Best Bike at Eurobike 2024velo.outsideonline.com World Bicycle Relief took over three years to make this new Buffalo S2, but its simple two-speed drivetrain feels worth the wait.

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David Elfstrom

What explains that some countries see a lot of heat pumps being installed whereas others lag behind? Key factor is the 'spark gap' - the ration of electricity to gas prices. I plotted heat pump sales per 1,000 households in 2023 against the spark gap. See the correlation?

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Reply to

c0nc0rdance

Two of the four people in this photo from the Trinity test died of acute radiation from the demon core. Given the cowboy antics of the earliest atomic age, it's surprising more weren't killed. A reminder that every lab safety rule is written in blood.

Fluorescent lighting containing mercury will disappear from the Canadian marketplace by the end of this decade, under rules set out in updated federal regulations governing mercury-containing products. www.reminetwork.com/articles/can... /1

Canada set to switch off fluorescent lighting - REMI Networkwww.reminetwork.com Fluorescent lighting set to disappear from the Canadian market by 2030 with new updates to the federal regulation governing mercury-containing products

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David Elfstrom

Heat pumps do work in high rise buildings. A 17-story Art Deco office building in NYC, built in 1931, is ditching its fossil-gas boiler for electric heat pumps providing both heating and cooling. www.canarymedia.com/articles/hea...

This NYC high-rise is using heat pumps and waste heat to cut fossil…www.canarymedia.com The cutting-edge, state-backed project at 345 Hudson could be a model for other big buildings sprinting to comply with the city’s building decarbonization law.

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David Elfstrom

Enbridge Gas is trying to incite a US-style culture war over gas grills and our "right to choose what energy we want to cook with." The Ontario Government is aiding and abetting them every step of the way.

Why is the Ontario government so in love with natural gas?lloydalter.substack.com And why is Enbridge Gas trying to incite a culture war?

If we're not going to install A/C in schools, at the very least set a classroom temperature threshold at which point occupancy is no longer permitted. www.cbc.ca/player/play/...

CBC’s Deana Sumanac-Johnson speaks with energy engineer David Elfstrom about air quality in schoolswww.cbc.ca Get the latest on CBCNews.ca, the CBC News App, and CBC News Network for breaking news and analysis

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David Elfstrom

I was reminded of this great figure created by Damon Matthews some 10+ years ago... Zero CO2 emissions (red) leads to declining CO2 concentrations & constant temperature. To maintain constant CO2 concentration (blue), requires continued CO2 emissions & rising temperature.

We're getting to the point where some schools in Canada without cooling should close for heat days just like for snow days.

When someone uses "draconian" to describe a rule they don't like, such as a mask mandate, they're being over-the-top hyperbolic.

'Draconian' laws are so named because Ancient Greek legislator Draco wrote the Athenian Constitution to include the death penalty for everything from stealing a cabbage to treason. When asked why: "even small crimes deserve death & I have no greater punishment for large crimes."

Mere hours after bringing this to the attention of Vancouver Coastal Health, they made edits!

Vancouver Coastal Health has released an updated Ventilation and Indoor Air Quality resource for Schools and Childcare Facilities (vch.ca/en/document-...) but their CO2 page needs some edits.

Alas, as @lloydalter.bsky.social has pointed out, 32% of Thames Water is owned by the Ontario Municipal Employees Retirement Fund (OMERS). It's disgusting that public workers in Canada are benefiting from water privatization overseas.

This is utterly outrageous. Days after cryptosporidium infection in Devon we have houses stuck by severe vomiting and diarrhoea in London with water the suspected cause- the English water system is broken while companies raked in profits. 💩💩💩 www.theguardian.com/environment/...

Thames Water tests for vomiting bug contamination as families fall sickwww.theguardian.com After cryptosporidium outbreak in Devon, residents in south-east London report stomach cramps and diarrhoea

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David Elfstrom

Reply to

Head In The Clouds

On a Chromium or Firefox browser, there's the Skyfollowerbridge that will help. github.com/kawamataryo/...

GitHub - kawamataryo/sky-follower-bridge: Instantly find and follow the same users from your X(Twitter) follower on Bluesky.github.com Instantly find and follow the same users from your X(Twitter) follower on Bluesky. - kawamataryo/sky-follower-bridge

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Never has a truer word been spoken (written) @racheldonald.bsky.social thank you for articulating this so eloquently! For anyone who has not read this, I strongly recommend you do. www.planetcritical.com/p/dont-talk-...

Don’t Talk To Me About Solutionswww.planetcritical.com The System Itself is the Problem

New ASHRAE 62.1-2022 #ventilation addendum adds density correction (PDF: ashrae.org/file%20libra...) Most locations will increase. Calgary #YYC at 1045 m will need 15% more outdoor air than before. Denver CO, 20% more.

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Apparently, I used the phrase "out of spoons" when talking to my mother. Apparently, she wasn't aware of the metaphorical use. I just got these in the mail.

What is this, a PC brand Gom Jabbar?

@tomflood.bsky.social You're not going to believe this but my 9 year old out of the blue asked me to unlock the cars so she could vacuum them. She's out there right now.

Article posted April 10 2024 on MSN (www.msn.com/en-us/travel...) regarding a new study of Indoor Air Quality in Canadian homes sounds interesting! Except: The institute, the quoted scientists, and the study don't exist. It's completely fabricated by generative AI, with poor sentence structure.

#Ventilation & CO2 Addendum ab (PDF: www.ashrae.org/file%20libra... ) to ASHRAE Std 62.1-2022 (Ventilation & Acceptable Indoor Air Quality) provides maximum CO2 levels for the minimum ventilation requirements. Example: 600ppm + Outdoor (420ppm)= 1020 ppm max for classroom

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David Elfstrom

That’s the thing about infectious aerosols…they hang in the air like smoke. So your aerosols can infect someone else long after you’ve left the room, as in this case

Um wow. And in a hospital setting, which should have better ventilation than pretty much anywhere else. www.ajicjournal.org/article/S019...

Evidence from Whole Genome Sequencing of Aerosol Transmission of SARS-CoV-2 almost Five Hours after Hospital Room Turnoverwww.ajicjournal.org Experimental evidence suggests that SARS-CoV-2 remains viable within aerosols with a half-life of approximately 3 hours; however, it remains unclear how long airborne SARS-CoV-2 can transmit infection...

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Canada has a major medical arrogance problem. It isn’t just about mode of transmission of sars-2. It impacts screening guidelines and results in cancers being caught late, with higher risk of death. globalnews.ca/news/1042369...

Health task force blasted over ‘dangerous guidance’ for cancer screenings - National | Globalnews.caglobalnews.ca Medical experts from radiologists to urologists are calling for an urgent need to reform the Canadian Task Force on Preventive Health Care for its 'outdated screening guidelines.'

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EDS PPL: this is a known issue for us and they do not recommend vaccination for us because of it. “benefit/risk balance is extremely unfavorable” There are millions of ppl with EDS and most of them don’t know it because it is rarely diagnosed! www.researchgate.net/publication/...

3 years ago today, I acquired a very rare form of vaccine-induced Long COVID. It sucks for so many reasons but one of the most difficult parts has been how isolating it's been. So anyway, if you have a health issue that isn't understood by society, you're not alone, I see you & I believe you.

(PDF) COVID-19 and Ehlers-Danlos syndrome: the dangers of the Spike protein of SARS-CoV-2www.researchgate.net PDF | On Jan 4, 2023, Ziad Fajloun and others published COVID-19 and Ehlers-Danlos syndrome: the dangers of the Spike protein of SARS-CoV-2 | Find, read and cite all the research you need on ResearchG...

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David Elfstrom

Reply to

Katharine Hayhoe

Here's Ontario, Canada "Ontario’s solar generation dropped from about 1,800 MW to about 70 MW as the IESO secured other generation to compensate"

New: Airborne disease transmission risks on public transit buses: Impacts of ridership, duration, and mechanical filtration using a relative risk metric www.sciencedirect.com/science/arti...

Airborne disease transmission risks on public transit buses: Impacts of ridership, duration, and mechanical filtration using a relative risk metricwww.sciencedirect.com Although public transportation vehicles often provide reasonable amounts of ventilation and air filtration, their small volumes and the close proximit…

Three years ago today. (April 6, 2021) Ontario's premier insists schools are safe. Toronto: Nope h/t @samanthajoyce.bsky.social from the original X post 3 years ago

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The importance of ventilation and air quality in schools: Covid spread in a school correlated with time of room CO2 concentration >1000 ppm, decrease of Covid with MERV-13 filters journals.plos.org/plosone/arti...