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Concentration of CO2 in the Atmosphere

Indoor Air Quality: Some Things to Know:

Diagram explaining how a heat recovery ventilator works. Image: Greentek

Michael Canavan

This article is a follow-up to “Understanding the Blower Door Test” published in the January 2020 issue of G.E.T.

Now that you have sealed your house as recommended from your blower door test results and verified that your house has an […]

DIY Blower Door Test

Very inexpensive fan used by author for her DIY blower door testing. It has a high cfm. Cut an oval hole in a tarp and tape the tarp to the fan. Put this in a door and let the air blow out of the house. It is magic at finding leaks! Courtesy photo.


DIY Energy Upgrades: Attics

Image: U.S. EPA

Dave Keefe

Attics are often miserable places. They’re cramped and dark, dusty and dirty. They’re hard to get into and hard to get out of. Most of the time they are either too hot or too cold. There’s usually nothing to stand on, even if there is room to stand, […]

LEDdynamics’ New Home: Above and Beyond Efficiency

LEDdynamics’ new super efficient facility on Beanville Road in Randolph, Vermont. All photos are courtesy of LEDdynamics.

George Harvey

Green Energy Times has run a number of articles on light emitting diodes (LEDs). Their cost keeps declining, and their efficiency keeps improving. Unquestionably, in our minds, they are the […]

Carbon Dioxide (CO₂), the Greenhouse Gas

Let’s get down to the basics: what is CO₂ and why should we even care?

Ball-and-stick model of the carbon dioxide molecule, one of the most important chemical compounds in the world. It is vital for life as we know it but catastrophic at excess levels. Color code: carbon, C is black; oxygen, […]

Resolve to Save the Earth


Alan Betts

OK, it is time to resolve to step away from our consumer stupor and save the Earth. Think of this as the last decade to wake up and stop destroying our planet and our children’s future. First stop and listen to the inner hubbub of familiar rationalizations for […]

A Trillion Trees

Young climate activist Greta Thunberg and eighty-four-year-old primatologist and anthropologist Jane Goodall at Davos, Switzerland in January 2019. Image:

John Bos

“It was the Africa I dreamed of when I was ten and fell in love with Tarzan,” said primatologist and anthropologist Jane Goodall in a recent interview with CNN’s Becky Anderson. […]

Book Review: On Fire: The (Burning) Case for a Green New Deal

by Naomi Klein, published by Simon & Schuster (2019), 322 pages

Review by Roger Lohr

Naomi Klein’s newest book, On Fire: The Burning Case for a Green New Deal, makes a persuasive case for the world to come together on climate change.

Klein ties together the notion that climate action is […]

AeroBarrier Case Study: Multi-family Renovation without Mechanical Ventilation

Preparation of living room for Aerobarrier installation showing the nozzle set-up. Courtesy photo.

Nate Gusakov

This is the fifth article in this series highlighting our experiences installing AeroBarrier around New England. Here’s a quick refresher on the technology.

AeroBarrier is a patented building envelope sealing technology that simultaneously measures and seals building envelope […]

Choosing Insulation for Carbon Value

Why More is Not Always Better (Part 1)

HFC blown-in SPF during the installation process. Courtesy images.

Catherine Paplin, R.A. AIA, Steven Winter Associates, Inc.

Insulation is the single most important material choice to maximize an enclosure’s thermal resistance. Combined with a good continuous air seal, the highest insulation value makes […]