The most recent blogs at Green Building Advisor

Installing Closed-Cell Spray Foam Between Studs is a Waste

Posted on March 17, 2017 by Martin Holladay in Musings of an Energy Nerd

Open-cell spray foam has an R-valueMeasure of resistance to heat flow; the higher the R-value, the lower the heat loss. The inverse of U-factor. of about R-3.7 per inch, while closed-cell spray foam has an R-value that may be as high as R-6.5 per inch. If you want to install spray foam in a stud wall, and price is no object, then it would seem to make sense to specify closed-cell spray foam, right?

Not necessarily.

Pete’s Puzzle: Fanciful Fuel

Posted on March 16, 2017 by Peter Yost in Building Science

A new client called me, saying that his insulation contractor urged him to contact me about some moisture problems in the home before they actually embarked on a major energy upgrade. (That was gratifying.) The home was actually moved many years ago off of a failing rubble foundation to a new concrete masonry unit (CMUConcrete masonry unit. Precast concrete block used to build walls. CMUs have hollow cores that can be filled with concrete onsite for additional reinforcement. The use of stronger, more lightweight types of concrete such as autoclaved aerated concrete (AAC) is becoming increasingly popular in CMU manufacture. ) foundation on a different site.

Image #2 (bottom of page) shows the home from the front. Image #3 shows the bare CMU on the above-grade portion of CMU foundation.

But it is Image #1 (right) that is the real puzzle. Here are the puzzle pieces:

Does a Bigger Volume Mean More Heating and Cooling Load?

Posted on March 15, 2017 by Allison A. Bailes III, PhD in Building Science

What happens to the heating and cooling loads when you encapsulate an attic? With the insulation and air barrierBuilding assembly components that work as a system to restrict air flow through the building envelope. Air barriers may or may not act as a vapor barrier. The air barrier can be on the exterior, the interior of the assembly, or both. at the ceiling below the attic, you're excluding the attic space. That volume of air up there isn't involved in the conditioning of the home. But when you move the enclosure to the roofline (usually by installing spray foam insulation beneath the roof deck), now the attic's volume is included in the conditioned spaceInsulated, air-sealed part of a building that is actively heated and/or cooled for occupant comfort. .

Occasionally I hear people say the loads will be higher because of the extra volume. Does having more air inside really increase the loads?

My Net Zero Conundrum

Posted on March 14, 2017 by Anonymous in Guest Blogs

By JEAN CARROON

Why would we want an individual building to be its own energy plant? This has never made sense to me. The scale seems inefficient and the potential of many existing urban buildings for net-zero energyProducing as much energy on an annual basis as one consumes on site, usually with renewable energy sources such as photovoltaics or small-scale wind turbines. (NZE) is limited. But many people I admire seem besotted by NZE. What am I missing?

CarMic House: Taming a Basement from Hell

Posted on March 13, 2017 by Carri Beer and Michael Hindle in Guest Blogs

Editor's note: Carri Beer and Michael Hindle are renovating a 1954 house in Catonsville, Maryland. Hindle is a Certified 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. Consultant and owner of Passive to Positive. Beer is a registered architect who has been practicing sustainable architecture for 18 years. She is an associate principal with Brennan+Company Architects. For a list of the couple's posts, see the “Related Articles” sidebar below. This post was written by Carri Beer.

A Visit to a LEED Platinum Office Building

Posted on March 10, 2017 by Martin Holladay in Musings of an Energy Nerd

While I’ve designed a few single-family homes, I’m well aware that designing a high-rise office building is a whole ’nother kettle of fish. The challenge is far greater — at least an order-of-magnitude greater — requiring an experienced team that includes architects, structural engineers, mechanical engineers, and energy consultants.

Airport House: Walls and Insulation

Posted on March 9, 2017 by Reid Baldwin in Guest Blogs

Editor’s note: This is the one of a series of guest blogs by Reid Baldwin about the construction of his house in Linden, Michigan. The first blog in the series was titled Energy Efficiency and Garage Space for an Airplane.

Manual J Doesn’t Tell You Equipment Capacity

Posted on March 8, 2017 by Allison A. Bailes III, PhD in Building Science

Here's a little conundrum for you. To get the right amount of heating and cooling to each room in your home, you need a load calculation. Rules of thumb don't work. But if you do a load calculation, the result isn't the size of air conditioner, heat pumpHeating and cooling system in which specialized refrigerant fluid in a sealed system is alternately evaporated and condensed, changing its state from liquid to vapor by altering its pressure; this phase change allows heat to be transferred into or out of the house. See air-source heat pump and ground-source heat pump., furnace, or boiler you need. It's only the first step to sizing your system.

Do you know why? Let's take a look.

From Red List to Ready List

Posted on March 7, 2017 by Anonymous in Guest Blogs

By JONATHAN A. WRIGHT

One of the primary goals of the Living Building Challenge (LBC) is to eliminate the use of known toxins in products installed in the built environment. If it is harmful to life — human, animal or anything else — do not use it if at all possible.

In 2016, Wright Builders Inc. completed two Living Buildings, which will be evaluated for certification over the next 18 to 24 months. These projects gave us a unique opportunity to work inside the largely unexplored new world of materials research, vetting, documentation, and advocacy.

Toronto Passive: Removable Basement Floors

Posted on March 6, 2017 by Lyndon Than in Guest Blogs

Editor's Note: Lyndon Than is a professional engineer and Certified 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. Consultant who took a year off from work to design and build a home with his wife Phi in North York, a district of Toronto, Ontario. A list of Lyndon's previous blogs at GBAGreenBuildingAdvisor.com appears below. For more, you can follow his blog, Passive House Toronto.

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