More from Martin Holladay
The Energy Grinch
The Energy Nerd's fourth annual Christmas parody
Are HRVs Cost-Effective?
Compared to a simple exhaust fan, a heat-recovery ventilator saves energy — but it probably won’t save enough to justify the high cost of the equipment
From 1977 (when the Saskatchewan Conservation house was built) until 2004 (when the first U.S. Passivhaus was built), North American builders completed hundreds of superinsulated homes. In those days, anyone interested in rating the performance of these homes was probably interested in just one metric: annual energy use.
- Photo: Martin Holladay — Bar graph and table: John Semmelhack
Live Webcast of a Building Science Seminar
GBA Pro members can watch two days of instruction from Joseph Lstiburek and John Straube
GBAGreenBuildingAdvisor.com has made arrangements to provide live video streaming of an educational seminar by two renowned building science experts, Joseph Lstiburek and John Straube. Dubbed the Building Science Experts' Session, the seminar is being held on Wednesday December 5 and Thursday December 6, 2012, in Westford, Massachusetts. Sessions begin each morning at 8:00 a.m. Eastern Standard Time.
The video stream will be available at no charge to all GBA Pro members. A link to the live video stream will be added to this page on the morning of December 5, 2012.
All About Wall Rot
If your wall sheathing is rotten, the first question to answer is: where did the moisture come from?
Contractors who specialize in repairing rotten walls won’t run out of work any time soon. The epidemic of wall-rot problems that began more than 20 years ago shows no signs of abating. In fact, wet-wall specialists are often called to investigate problems in developments where most of the homes have rotting walls — and in some cases, these homes are only six years old.
- Photo with pipe staging: Will Smith — Rot under window: Mark Parlee (MP) — Splashback: Fairhope Farm — No kickout: MP — Missing step flashing: MP — Missing deck flashing: Everflashing — Ice dam: Ecduzitgood — Solar vapor drive: MP — Exfiltration: FHB
BuildingGreen Announces Top 10 Green Building Products
This year’s list includes cork insulation, a heat-pump water heater, a new low-e coating, and WUFI software
Proponents of green building have spent years fighting the impression that sustainable design is all about product selection. It's difficult to swim upstream against the tide of American consumerism, but it's important to keep repeating an important truism: green building depends on following an integrated designBuilding design in which different components of design, such as the building envelope, window placement and glazings, and mechanical systems are considered together. High-performance buildings and renovations can be created cost-effectively using integrated design, since higher costs one place can often be paid for through savings elsewhere, for example by improving the performance of the building envelope, the heating and cooling systems can be downsized, or even eliminated. process, on minimizing the size of the building, and on designing for energy efficiency. You can't make a bad building green by specifying a few “green” building materials.
Passivhaus Practitioners Share Their Success Stories
The Fall Symposium sponsored by Passive House New England included presentations from designers, builders, and homeowners
A group of about 130 designers, builders, and Passivhaus fans gathered at U Mass Boston on October 27, 2012 to attend a one-day conference organized by 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. New England.
It's impossible for this report to be comprehensive, unfortunately, and I won't be able to do justice to all of the conference events. My report will focus on three speakers: Adam Cohen, Chris Corson, and Roger Normand.
- Adam Cohen
- Martin Holladay
- Chris Corson
- Roger Normand
Fans in the Attic: Do They Help or Do They Hurt?
Homeowners in hot climates need to understand the difference between whole-house fans and powered attic ventilators
There’s a lot of confusion surrounding attic fans. Here at GBAGreenBuildingAdvisor.com, we regularly receive e-mails from homeowners with questions about attic fans: What’s the purpose of the fan in my attic? How often should I run it? Do I need a bigger fan?
Before addressing these recurring questions, it’s important to define our terms. First, we need to distinguish between three different types of ventilation fans.
- U.S. DOE
- Tamarack Technologies
- Pacific Gas & Electric
Rating Windows for Condensation Resistance
Window shoppers are confused by the two rival methods for measuring condensation resistance
Condensation forms on a surface when the temperature of the surface is below the dew point of the air. During the winter, when the coldest surface in a room is often the window, it’s fairly common to see water droplets or ice on window glass — especially in a room with elevated indoor humidity.
Condensation is more likely to form when indoor relative humidity is high. That’s why it’s more common to see condensation on a bathroom window than a bedroom window.
- Dr. Zhivago
- Tracy Rogers
- Steve Easley
Calling all Weatherization Workers
The DOE wants to interview weatherization workers and home performance contractors to find out more about the ‘values, opportunities, and challenges’ of their work
The U.S. Department of Energy (DOEUnited States Department of Energy.) wants to standardize and professionalize the work of weatherization and home performance contractors. Towards that end, the government agency has launched a project called the “Guidelines for Home Energy Professionals” project.
Air Leakage Degrades the Thermal Performance of Walls
No surprises here — but testing by the Building Science Corporation begins to quantify the problem
For the past five years, researchers at the Building Science Corporation (BSC) in Massachusetts have been testing the thermal performance of a variety of wall assemblies as part of an ambitious project to develop a new metric to replace R-valueMeasure of resistance to heat flow; the higher the R-value, the lower the heat loss. The inverse of U-factor. . (I last reported on the project in my August 2011 article, A Bold Attempt to Slay R-Value.)