Musings of an Energy Nerd

What follows is a reconstruction of Martin Holladay’s keynote address at 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. Northwest conference in Olympia, Washington, on March 18, 2011. The piece has been fleshed out somewhat, in light of the fact that the original time constraints no longer apply. For the most part, each paragraph corresponds to one slide of the accompanying PowerPoint presentation.

Click here to view the presentation slides

Are Passivhaus requirements logical or arbitrary?

It’s been about six months since my last roundup of new green building products. This time I’ll look at two ventilation products (an HRV(HRV). Balanced ventilation system in which most of the heat from outgoing exhaust air is transferred to incoming fresh air via an air-to-air heat exchanger; a similar device, an energy-recovery ventilator, also transfers water vapor. HRVs recover 50% to 80% of the heat in exhausted air. In hot climates, the function is reversed so that the cooler inside air reduces the temperature of the incoming hot air. and a fan), a pressure-balancing grille, and an inexpensive camera to inspect difficult-to-reach areas. I’ll also mention four new North American distributors of European PassivhausA 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.-certified windows.

Because forced-air heating and cooling systems are assembled on site from a great many parts, there are many ways for installers to make mistakes. Researchers have repeatedly shown that a high percentage of residential forced-air systems have major problems, including duct systems that are poorly designed, poorly located, and leaky. Other problems include incorrect refrigerant charge and too much or too little airflow over the cooling coil.

In some parts of the U.S. — notably northern New England — cellulose insulationThermal insulation made from recycled newspaper or other wastepaper; often treated with borates for fire and insect protection. has been widely used for more than 30 years. In other parts of the U.S., however, cellulose insulation is just beginning to gain traction.

Of course, cellulose insulation is installed with different techniques than those used to install fiberglass batts or spray foam. To help explain these techniques to builders who are unfamiliar with cellulose, we decided to interview Bill Hulstrunk, the technical manager at National Fiber, a manufacturer of cellulose insulation in Belchertown, Massachusetts.

Beginning on January 1, 2012, homes enrolled in the Energy Star HomesA U.S. Environmental Protection Agency (EPA) program to promote the construction of new homes that are at least 15% more energy-efficient than homes that minimally comply with the 2004 International Residential Code. Energy Star Home requirements vary by climate. program will need to comply with a new specification — dubbed Energy Star Version 3 — that is stricter than the current Version 2 specification.

If you’re interested in residential energy efficiency, you’re probably familiar with the marketing pitch of the EPA’s Energy Star HomesA U.S. Environmental Protection Agency (EPA) program to promote the construction of new homes that are at least 15% more energy-efficient than homes that minimally comply with the 2004 International Residential Code. Energy Star Home requirements vary by climate. program.

Among the program’s claims:

Let’s say you’re building a house with plywood or OSB 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. . You plan to install 2 or 4 inches of rigid foam on the exterior of the wall sheathing, followed by vertical rainscreenConstruction detail appropriate for all but the driest climates to prevent moisture entry and to extend the life of siding and sheathing materials; most commonly produced by installing thin strapping to hold the siding away from the sheathing by a quarter-inch to three-quarters of an inch. strapping and siding. Where does the housewrap go?

Depending on who you talk to, you get two different answers:

• It goes between the rigid foam and the vertical strapping, or
• It goes between the sheathing and the rigid foam.

Designing a superinsulated house can be tough. How much insulation should you install under a slab? Should your walls be sheathed with rigid foam, or should you go with double-stud walls? Could SIP(SIP) Building panel usually made of oriented strand board (OSB) skins surrounding a core of expanded polystyrene (EPS) foam insulation. SIPs can be erected very quickly with a crane to create an energy-efficient, sturdy home. walls save you money? Does the added cost of triple glazingWhen referring to windows or doors, the transparent or translucent layer that transmits light. High-performance glazing may include multiple layers of glass or plastic, low-e coatings, and low-conductivity gas fill. make sense?

Residential energy codes have evolved rapidly over the last two decades. The origin of many of our current energy codes can be traced back to the Model Energy Code (MEC), which was first introduced in 1992. The MEC eventually evolved into the International Energy Conservation Code (IECC International Energy Conservation Code.).

When I published my first Energy Quiz over a year ago, a reader posted the comment: “I want another quiz.” Okay — we aim to please.

Remember, using Google for research is cheating. Answers are at the bottom of the page.

1. Evaporative coolers:
a. Perform better in a dry climate than a humid climate.
b. Perform better in a humid climate than a dry climate.
c. Don’t work very well anywhere in the U.S.