The most recent blogs at Green Building Advisor

Garbage In, Garbage Out

Posted on March 15, 2018 by Ana Baptista in Guest Blogs

U.S. cities have been burning municipal solid waste since the 1880s. For the first century, it was a way to get rid of trash. Today, advocates have rebranded it as an environmentally friendly energy source.

Most incinerators operating today use the heat from burning trash to produce steam that can generate electricity. These systems are sometimes referred to as “waste-to-energy” plants.

Is a Ventless Fireplace More Efficient Than a Condensing Furnace?

Posted on March 14, 2018 by Allison A. Bailes III, PhD in Building Science

One of the primary benefits of a ventless gas fireplace is that you don't lose any heat up the flue. That's because there isn't a flue, of course. (The potential problems with indoor air quality, however, outweigh any benefits, so don't run out and buy one just yet. Or ever.) That ought to make it a winner for heating efficiency in comparison to any vented heating appliance, such as furnace or boiler. Even the highest efficiency condensing furnaces still lose some heat in the exhaust gases that go up the flue.

What Is a Green Home Worth?

Posted on March 13, 2018 by Parlin Meyer in Guest Blogs

Editor's note: This article originally appeared in Green & Healthy Homes Maine and is reprinted here with permission.

Flatrock Passive: Air Sealing the Penetrations

Posted on March 12, 2018 by David Goodyear in Guest Blogs

Editor's Note: This is one of a series of blogs by David Goodyear describing the construction of his new home in Flatrock, Newfoundland, the first in the province built to the Passive HouseA residential building construction standard requiring very low levels of air leakage, very high levels of insulation, and windows with a very low U-factor. Developed in the early 1990s by Bo Adamson and Wolfgang Feist, the standard is now promoted by the Passivhaus Institut in Darmstadt, Germany. To meet the standard, a home must have an infiltration rate no greater than 0.60 AC/H @ 50 pascals, a maximum annual heating energy use of 15 kWh per square meter (4,755 Btu per square foot), a maximum annual cooling energy use of 15 kWh per square meter (1.39 kWh per square foot), and maximum source energy use for all purposes of 120 kWh per square meter (11.1 kWh per square foot). The standard recommends, but does not require, a maximum design heating load of 10 W per square meter and windows with a maximum U-factor of 0.14. The Passivhaus standard was developed for buildings in central and northern Europe; efforts are underway to clarify the best techniques to achieve the standard for buildings in hot climates. standard. The first installment of the blog series was titled An Introduction to the Flatrock Passive House. For a list of Goodyear's earlier blogs on this site, see the "Related Articles" sidebar below; you'll find his complete blog here.

Carbon Emissions By the Construction Industry

Posted on March 9, 2018 by Martin Holladay in Musings of an Energy Nerd

Burning fossil fuels or using electricity results in carbon dioxide emissions (unless the electricity is produced by photovoltaics, wind, or another renewable energy source). Since CO2 emissions cause global climate change, environmentally conscious builders aim to build energy-efficient buildings.

A Chinese Firm Is Convicted of Stealing Trade Secrets

Posted on March 8, 2018 by Stuart Kaplow in Guest Blogs

While many people focused on the tariffs of 30% imposed by the United States on imported photovoltaic(PV) Generation of electricity directly from sunlight. A photovoltaic cell has no moving parts; electrons are energized by sunlight and result in current flow. cells and modules last month, most missed the larger renewable energy news story: After an 11-day trial, a federal jury in Wisconsin convicted the Chinese firm Sinovel of stealing wind technology, including trade secrets.

A Better Way to Encourage Efficient New Homes

Posted on March 7, 2018 by David Goldstein in Guest Blogs

Building a more energy-efficient home can employ many different approaches. The builder can use more insulation and better windows, install ductless heating and cooling systems, orient the house to collect sunshine through the windows in winter and shade them in summer, seal leaks in the walls and ceilings, and assure healthy indoor air 24/7 by providing reliable mechanical ventilation with energy recovery. They can use cool roofs. The list goes on...

Solving an Ice Dam Problem With Exterior Rigid Foam

Posted on March 6, 2018 by Pauline Guntlow in Guest Blogs

Because of improved product and installation methods, techniques to build new or remodel existing homes have advanced dramatically in the past few decades. In 2017, I used one of these innovations — continuous exterior insulation — to solve ice damA ridge of ice that forms along the lower edge of a roof, possibly leading to roof leaks. Ice dams are usually caused by heat leaking from the attic, which melts snow on the upper parts of the roof; the water then refreezes along the colder eaves working it's way back up the roof and under shingles. and heat loss issues of my seven-unit apartment building located in Pownal, Vermont.

Updating a Massachusetts Colonial

Posted on March 5, 2018 by Scott Gibson in Q&A Spotlight

In coastal Massachusetts, Justin Brown is looking for ways to upgrade the energy performance of his very old house. It sounds as if previous owners had taken some steps to tighten up the building envelopeExterior components of a house that provide protection from colder (and warmer) outdoor temperatures and precipitation; includes the house foundation, framed exterior walls, roof or ceiling, and insulation, and air sealing materials., but they didn't go far enough with either air sealing or insulation. Now, Brown wants to complete the job.

One area of particular concern is the attic. It's insulated with a mix of fiberglass and cellulose, he writes in a Q&A post, but a cold snap this winter produced some frost on the underside of the roof sheathingMaterial, usually plywood or oriented strand board (OSB), but sometimes wooden boards, installed on the exterior of wall studs, rafters, or roof trusses; siding or roofing installed on the sheathing—sometimes over strapping to create a rainscreen. .

Finally, a Right-Sized Furnace

Posted on March 2, 2018 by Martin Holladay in Musings of an Energy Nerd

For years, builders of energy-efficient homes have been frustrated by the lack of low-load furnaces. An article I wrote in 2013 about this problem began with this question: “Why are the smallest available American furnaces rated at about 40,000 BtuBritish thermal unit, the amount of heat required to raise one pound of water (about a pint) one degree Fahrenheit in temperature—about the heat content of one wooden kitchen match. One Btu is equivalent to 0.293 watt-hours or 1,055 joules. /h?”

A 40,000 Btu/h furnace is likely to be more than twice the size of what is needed to heat a small energy-efficient home. Many homes in this category have a design heat load of only 12,000 or 15,000 Btu/h.

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