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How We Chose Our Heat-Recovery Ventilator

Posted February 12, 2014 11:06 PM by Alex Wilson
Related Categories: Energy Solutions, GreenSpec Insights

Zehnder’s state-of-the-art HRV will provide years of service in providing fresh air with very low energy consumption.

Barry Stephens installing the condensate drain on our Zehnder ComfoAir 350 Luxe HRV. Click to enlarge.
Photo Credit: Alex Wilson

Balanced ventilation requires two fans: one bringing fresh air into the house and one exhausting indoor air (see 6 Ways to Ventilate Your Home). By balancing these two fans and the airflow through their respective ducts, the house is maintained at a neutral pressure—which is important for avoiding moisture problems or pulling in radon and other soil gases.

6 Ways to Ventilate Your Home (and Which is Best)

Posted February 5, 2014 2:46 PM by Alex Wilson
Related Categories: Energy Solutions, GreenSpec Insights

How a green home really "breathes"

Should a green home require a piece of ventilation equipment like our Zehnder HRV?
Photo Credit: Alex Wilson

One of the features in our new house that I’m most excited about barely raises an eyebrow with some of our visitors: the ventilation system. I believe we have the highest-efficiency heat-recovery ventilator (HRV) on the market—or at least it’s right up there near the top.

But first, a lot of people may be wondering, should a "green" home require mechanical ventilation? A lot of people might think that this is just the kind of energy-consuming system that homes should be getting away from—while cracking windows for fresh air.

Cold Weather Tests the Limits of Our Mini-Split Heat Pump

Posted January 29, 2014 11:30 AM by Alex Wilson
Related Categories: Energy Solutions, GreenSpec Insights

Testing the limits of the air-source heat pump in our new house with this cold weather

The interior unit of our Mitubishi air-source heat pump. Click photos to enlarge.
Photo Credit: Alex Wilson

It’s been pretty chilly outside. A number of people have asked me how our air-source heat pump is making out in the cold weather. I wrote about ths system last fall, well before we had moved in to our new home. Is it keeping us warm?

First, if you want to get up to speed on the surprising and counterintuitive nature of how an air-source heat pump works, check out our primer on the topic—which includes a great diagram.

We’ve only been living in the house for a few weeks, but so far, so good. Our 18,000 Btu/hour Mitsubishi mini-split heat pump (MSZ FE18NA indoor unit and MUZ FE18 outdoor unit) is doing remarkably well in keeping us comfortable. We don’t have any oil or gas heating in the house, only the electric heat pump and a small wood stove that we’ve fired up twice so far.

The indoor heat pump unit is mounted on a wall next to our kitchen, and it’s been operating pretty steadily in this cold weather. (Even though we’ve heated with wood for decades and have all the wood we could ever use, I’ve been curious how the house will do just on electricity, so have refrained from using the wood stove.)

On the Benefits of Online Learning

Posted January 21, 2014 12:27 PM by Alex Wilson
Related Categories: Energy Solutions

With a new group of online BAC courses starting this week, I’m reminded of the benefits of learning—and teaching—from home.

San Francisco Bay Area traffic. Click to enlarge.
Photo Credit: Getty Images

Truth be told, I was slow warming up to online instruction. Ten years ago, in early 2004, BuildingGreen was approached by Boston Architectural College (then Boston Architectural Center—but with the same acronym BAC) about collaborating on sustainable design curriculum. There is so much value in face-to-face instruction and student interaction, I thought, how could online instruction take its place?

But we did collaborate, helping BAC develop it’s Sustainable Design curriculum. And I created and for a number of years taught one of the foundation online courses for the program: “Sustainable Design as a Way of Thinking,” which is now being taught by my friend David Foley.

This assemblage of courses, now housed in BAC’s Sustainable Design Institute, offers the most comprehensive, accredited online instruction in sustainable design anywhere. There are nearly three dozen courses offered that can be taken as continuing education courses by anyone, taken as part of graduate degree programs, or taken as electives as part of a relatively new MDS (Masters in Design Studies) program in Sustainable Design that is now in its third year.

Look Under the Sea for Safe Nuclear Waste Storage

Posted January 15, 2014 4:35 PM by Alex Wilson
Related Categories: Energy Solutions
Workers entering the Yucca Mountain nuclear waste storage facility in 2006.
Photo Credit: Isaac Breekken, AP

With nowhere on land to turn, we should look under the seabed for places to bury high-level nuclear waste

For more than 30 years the nuclear industry in the U.S. and nuclear regulators have been going down the wrong path with waste storage—seeking a repository where waste could be buried deep in a mountain. Nevada’s Yucca Mountain was the place of choice until…it wasn’t.

Any time we choose to put highly dangerous waste in someone’s backyard, it’s bound to cause a lot of NIMBY opposition, even in a sparsely populated, pro-resource-extraction place like Nevada, and in the case of Yucca Mountain, powerful Nevada senator Harry Reid has hardened that opposition politically.

Aside from NIMBYism, the problem with burying nuclear waste in a maintain (like Yucca Mountain) or salt caverns (like New Mexico’s Carlsbad Caverns—an earlier option that was pursued for a while in the 1970s) is that the maximum safety is provided at day one, and the margin of safety drops continually from there. The safety of such storage sites could be compromised over time, due to seismic activity (Nevada ranks fourth among the most seismically active states), volcanism (the Yucca Mountain ridge is comprised mostly of volcanic tuff, emitted from past volcanic activity), erosion, migrating aquifers, and other natural geologic actions.

A better storage option

I believe a much better solution for long-term storage of high-level radioactive waste is to bury it deep under the seabed in a region free of seismic activity where sediment is being deposited and the seafloor getting thicker. In such a site, the level of protection would increase, rather than decrease, over time.

Stay Safe When Using Space Heaters and Wood Stoves

Posted January 8, 2014 7:43 PM by Alex Wilson
Related Categories: Energy Solutions

Cold weather, when wood stoves are cranked up and portable electric space heaters are brought out of the basement and plugged in, is when most house fires occur

Enjoying a wood stove on a cold winter day.
Photo Credit: Alex Wilson

The morning paper had yet another story about a destructive house fire—fortunately no fatalities (this time*), but the total loss of another home and another family’s belongings. And like many others, the culprit appears to have been the wood stove.

So many of the home fires we experience in Vermont result from trying to keep warm. Some have to do with faulty installation of wood heating equipment; many others result from improper operation of that equipment or management of the ash.

My Green Policy Wishlist for 2014

Posted January 2, 2014 9:53 AM by Alex Wilson
Related Categories: Energy Solutions, Op-Ed

 

Six items on my policy wish-list for 2014 and beyond.

Safe bicycle commuting and walking is high on my wish list for 2014.
Photo Credit: Yuba Cargo Bikes

It's fun for me to dream about stuff—building products and materials—and how we can make that stuff greener. I recently wrote about 7 wish-list items for greener building products and materials. Today I want to talk policy—six changes we need in the public sphere to bring more sustainability to our built environment and beyond.

1) Strengthen building codes by recognizing resilience

I believe that the need for buildings and communities that can withstand heat waves, more intense storms, flooding, drought, and other effects of a changing climate—as well as problems wrought directly by our fellow humans (like terrorism)—point to the need for strengthening building codes and land-use regulations.

7 Green Building Wishes for 2014

Posted December 26, 2013 9:43 AM by Alex Wilson
Related Categories: Energy Solutions, GreenSpec Insights

Here are some green product developments I’d like to see in the New Year

A plug-in hybrid vehicle charged using a net-metered PV array at the Philadelphia Navy Yard. I want to see the market share of plug-in vehicles double next year. Click to enlarge.
Photo Credit: Alex Wilson

I spend a lot of time writing about innovations in the building industry—the cool stuff that’s coming out all the time. But I also like to think about what’s needed: stuff that’s not (yet) on the market or performance levels not yet available.

1) Rigid insulation with no flame retardants and insignificant global warming potential

We've been highly critical of the brominated and chlorinated flame retardant chemicals added to nearly all foam-plastic rigid insulation today as well as the high-global-warming-potential blowing agents used in extruded polystyrene (see Can We Replace Foam Insulation?). I would love to see affordable alternatives. They could be new formulations of polystyrene or polyisocyanurate that doesn’t require flame retardants or inorganic materials that are inherently noncombustible (see our review of cool new products from Greenbuild for some advances). I’m intrigued by advanced ceramics and could imagine a foamed ceramic insulation being developed that meets these criteria.

Your Picks: 10 Hottest Green Building Topics of 2013

Posted December 19, 2013 3:22 PM by Paula Melton
Related Categories: BuildingGreen's Top Stories

Boora Architects is designing a 22,000 ft2 early childhood center addition for the Earl Boyles School in Portland, Oregon. Boora has switched to mineral wool as its standard insulation material for rainscreen walls like this one, in part because of toxicity concerns with foam insulation materials. Image: Boora ArchitectsBoora Architects is designing a 22,000 ft2 early childhood center addition for the Earl Boyles School in Portland, Oregon. Boora has switched to mineral wool as its standard insulation material for rainscreen walls like this one, in part because of toxicity concerns with foam insulation materials. Image: Boora ArchitectsCan we replace foam insulation? What does energy modeling really tell us? Find out what you, our readers, have picked as this year’s top 10 stories!

Our resident number-crunchers have spent hours slaving over metrics to bring you … your own most-read BuildingGreen stories of the year. Ta-da!

We just have to say, you guys have great taste. If you don’t see your favorite article listed here, though, tell us what it is—and why—in the comments.

And don’t forget that BuildingGreen members can collect CEUs—for LEED, AIA, and ILFI—for many of these popular articles. Just read the story, take the quiz, and we do the reporting for you.

10. On the grid, off the grid

Islandable Solar: PV for Power Outages” reveals a conundrum of grid-connected PV: it can’t be used during a power outage! Click through to learn about your three options for greater resilience (and check out #8 too).

9. Say it after me: AH-ge-pahn

Yeah, it’s spelled like “age pan,” but we swear it’s got a lot going for it, starting with German engineering (and pronunciation). Learn more about “Agepan: A Vapor-Permeable, Wood-Based Insulation Board” in our product review.

8. Awesome products!

Last month, we selected our favorite forward-looking products for 2014, and you selected our story as one of the most popular articles of the year. Our choices solve key design and environmental problems, but more importantly, Lloyd Alter called them “sexy”!

7. Taking charge of our own pee and poop

NIMBYism Alert: Opposition to "Industrial" Solar Projects

Posted December 18, 2013 5:18 PM by Alex Wilson
Related Categories: Energy Solutions

Are we going to find the same NIMBY opposition to larger solar systems that we’re experiencing today with wind farms? 

The 197 kW solar array at Logan Airport in Boston—on the top level of the Terminal B parking garage. Click to enlarge.
Photo Credit: Alex Wilson

When the economy-of-scale with wind power led to larger and larger wind turbines, opponents of these installations took to referring to them as “industrial wind power.” Whenever I see a letter-to-the-editor or news story that uses this identity I can tell that it’s going to have an anti-wind bias.

Whether its marring their views of pristine mountains, blighting their night sky with blinking red lights, causing bird and bat fatalities, or producing “infrasound” pollution, opponents almost universally refer to these wind farms using an industrial moniker.

So, I’m becoming troubled by recent reference to “industrial solar” in describing the larger photovoltaic (PV) installations that are cropping up in Vermont and nationwide. Some opposition seems to be emerging, for example, to a 2 megawatt (MW) array that’s being proposed for Brattleboro, and I’m hearing more and more such concerns nationally.

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