Jul 28, 2017

City trees save heating costs

Picture of the neighborhood modeled is attached, credit is University of British Columbia.

When it comes to designing an energy-efficient city, think green. Even a single, leafless tree can serve as a significant windbreak for pedestrians. But, more importantly, trees also block wind pressure on buildings which helps keep heating costs down, according to a study published in the journal Advances in Water Resources.

Why it matters: Everyone knows a windy day feels cooler than a still one – the same is true for buildings. As much as one-third of a building's heat loss and energy consumption can be caused by wind pressure. Past models and observational studies have shown how trees impact wind in cities, but this is the first time scientists have simulated the effects in a real, replicated neighborhood.

What they did: The scientists created a computer model of Vancouver that included every building and tree. They modeled airflow around the buildings in three scenarios: one with leafy summer trees, leafless winter trees, and no trees at all.

"Using our model, we found that removing all the trees around buildings drove up the building's energy consumption by as much as 10% in winter and 15% in summer," said Marco Giometto, a civil engineer at the University of British Columbia in Vancouver and an author on the study.

The bottom line: Trees make a difference in cities even in the wintertime. Even bare winter branches reduced pressure on the buildings, the research showed.

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Coronavirus dashboard

Illustration: Sarah Grillo/Axios

  1. Global: Total confirmed cases as of 8 a.m. ET: 679,977 — Total deaths: 31,734 — Total recoveries: 145,625.
  2. U.S.: Leads the world in cases. Total confirmed cases as of 8 a.m. ET: 124,686 — Total deaths: 2,191 — Total recoveries: 2,612.
  3. Federal government latest: Trump announces new travel advisories for New York, New Jersey and Connecticut, but rules out quarantine enforcement. Per CDC, those residents should "refrain from non-essential domestic travel for 14 days," with the exception of critical infrastructure industry workers.
  4. State updates: Alaska issues a stay-at-home order — New York tries to nearly triple hospital capacity in less than a month and moved presidential primary to June 23. Some Midwestern swing voters who backed Trump's initial handling of the virus balk at call for U.S. to be "opened up" by Easter.
  5. World updates: In Spain, over 1,400 people were confirmed dead between Thursday to Saturday.
  6. 🚀 Space updates: OneWeb filed for bankruptcy amid the novel coronavirus pandemic.
  7. What should I do? Answers about the virus from Axios expertsWhat to know about social distancingQ&A: Minimizing your coronavirus risk
  8. Other resources: CDC on how to avoid the virus, what to do if you get it.

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