Musings of an Energy Nerd

Can Swimming Pools Be Green?

Posted on May 12, 2009 by Martin Holladay

Question: What do the following homes have in common?

  • An 11,000-square-foot home in St. Charles, Ill., touted as “one of the greenest homes in the Chicago area.”
  • A 5,100-square-foot home at Live Oaks Estates in San Rafael, Calif., marketed as green by an Eco-Broker.
  • A 6,100-square-foot home in West Vancouver, British Columbia, aiming for LEED for HomesLeadership in Energy and Environmental Design. LEED for Homes is the residential green building program from the United States Green Building Council (USGBC). While this program is primarily designed for and applicable to new home projects, major gut rehabs can qualify. Gold certification.
  • A 3,000-square-foot home on Block Island, R.I., aiming for LEED for Homes Silver certification.

‘Innie’ Windows or ‘Outie’ Windows?

Posted on May 6, 2009 by Martin Holladay

UPDATED on April 3, 2016

Builders in northern states and Canada often specify exterior wall foam for new construction as well as for residing jobs on existing houses. Installing rigid foam on exterior walls reduces thermal bridgingHeat flow that occurs across more conductive components in an otherwise well-insulated material, resulting in disproportionately significant heat loss. For example, steel studs in an insulated wall dramatically reduce the overall energy performance of the wall, because of thermal bridging through the steel. through studs and (as long as the foam is thick enough) greatly reduces the chances of condensation in wall cavities. Current trends favor thicker and thicker foam; many cold-climate builders now routinely install 4 or 6 inches of EPSExpanded polystyrene. Type of rigid foam insulation that, unlike extruded polystyrene (XPS), does not contain ozone-depleting HCFCs. EPS frequently has a high recycled content. Its vapor permeability is higher and its R-value lower than XPS insulation. EPS insulation is classified by type: Type I is lowest in density and strength and Type X is highest., XPSExtruded polystyrene. Highly insulating, water-resistant rigid foam insulation that is widely used above and below grade, such as on exterior walls and underneath concrete floor slabs. In North America, XPS is made with ozone-depleting HCFC-142b. XPS has higher density and R-value and lower vapor permeability than EPS rigid insulation., or polyisoPolyisocyanurate foam is usually sold with aluminum foil facings. With an R-value of 6 to 6.5 per inch, it is the best insulator and most expensive of the three types of rigid foam. Foil-faced polyisocyanurate is almost impermeable to water vapor; a 1-in.-thick foil-faced board has a permeance of 0.05 perm. While polyisocyanurate was formerly manufactured using HCFCs as blowing agents, U.S. manufacturers have now switched to pentane. Pentane does not damage the earth’s ozone layer, although it may contribute to smog. on exterior walls.

Sam Rashkin Announces New Energy Star Homes Specifications

Raising the Bar for Energy Star Homes

Posted on April 29, 2009 by Martin Holladay

Over a thousand home performance contractors, weatherization experts, HERS raters, and energy nerds are gathered in Kansas City, Missouri, this week to attend the ACI Home Performance conference (formerly known as the Affordable Comfort conference).

At one well-attended workshop, energy consultant Michael Blasnik and Shaun Hassel of Advanced Energy Corporation shared a roundup of data on the performance of Energy Star homes — data which are unlikely to be happily received at the U.S. Environmental Protection Agency (EPA). Among the findings presented by Blasnik and Hassel:

    What Is Sustainable

    What Does ‘Sustainable’ Mean?

    Posted on April 23, 2009 by Martin Holladay

    In the U.S. and Canada, many residential builders use the word “sustainable” as a synonym for “green.” We hear about sustainable development, sustainable homes, and sustainable building products.

    Now that the word “sustainable” has become ubiquitous — even at the GreenBuildingAdvisor Web site, where a new $736,000 home on the coast of Maine is described as a “sustainable spec house” — it’s time to take a step back and consider the word’s history.

    Forgotten Pioneers of Energy Efficiency

    Posted on April 17, 2009 by Martin Holladay

    In 1977, a group of Canadian researchers built a demonstration house in Regina. Called the Saskatchewan Conservation House, the nearly airtight building had triple-glazed windows, R-40 wall insulation, R-60 roof insulation, and one of the world’s first heat-recovery ventilators.

    The home’s design and engineering team included Robert Besant, Oliver Drerup, Rob Dumont, David Eyre, and Harold Orr. That same year, Gene Leger, a Massachusetts builder, finished a similar superinsulated house in Pepperell, Mass.

    Complicated Equipment

    Simplicity versus Complexity

    Posted on April 9, 2009 by Martin Holladay

    Designers of energy-efficient homes — especially homes aiming 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. use — must inevitably grapple with the question of simplicity versus complexity.

    Residential designers can choose from an array of sophisticated appliances that improve comfort and help homeowners reduce energy use. Examples include heat-recovery ventilators (HRVs), condensing boilers, ground-source heat pumps, solar hot water systems, on-demand water heaters, heat-pump water heaters, 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. modules, and co-generation systems.

    Indoor AirPlus Specs Are Ahead of the Data

    The EPA’s Indoor AirPlus Program

    Posted on April 3, 2009 by Martin Holladay

    The U.S. Environmental Protection Agency (EPA) is inviting builders to adopt specifications for new homes that are “designed for improved indoor air quality compared to a home built to minimum code.” The EPA calls its new program Indoor AirPlus.

    Toxic and non toxic building materials

    Toxic and Non-Toxic Houses

    Posted on March 31, 2009 by Martin Holladay

    Are green builders more fearful than most Americans? It would certainly appear so, since so many of them show signs of an almost paranoid obsession with toxins.

    Understanding R-Value 2

    Understanding R-Value

    Posted on March 24, 2009 by Martin Holladay

    R-valueMeasure of resistance to heat flow; the higher the R-value, the lower the heat loss. The inverse of U-factor. measurements are subject to a fair amount of ridicule, especially by marketers of radiant barriers. As it turns out, however, the ridicule is mostly unwarranted.

    Energy Auditors Make You Tube Video

    A Music Video For Energy Auditors

    Posted on March 18, 2009 by Martin Holladay

    Is it possible to make a funny music video on the topic of residential energy audits? It sounds unlikely. But a group of Stanford University students have risen to the challenge. Check it out.

    Register for a free account and join the conversation


    Get a free account and join the conversation!
    Become a GBA PRO!

    Syndicate content