Musings of an Energy Nerd

For those interested in energy efficiency and residential construction, what were the top ten news stories of the decade? I propose the following list — a list inevitably influenced by the years I spent as editor of Energy Design Update.

’Twas the night before Christmas, when blizzards and chills
Strain my budget by raising my energy bills;
All the stockings were swaying — a cold winter breeze
Made my home’s leaky envelope feel like Swiss cheese
(The old windows and ceilings have so many gaps
That the kids have to sleep in their kerchiefs and caps) —
When out on the lawn there arose such a clatter,
I sprang from the bed to see what was the matter.

Away to the window I flew like a flash,
And I yanked up the creaky old single-pane sash.

This week’s blog is an energy efficiency and building science quiz. Remember, using Google for research is cheating. Answers are at the bottom of the page.

1. During the winter, a home inspector climbs into an attic and notices that the underside of the roof sheathing is covered with frost and the rafters have stains indicating mold. The most likely cause of these problems is:
a. A roof leak
b. Insufficient insulation on the attic floor
c. Air leakage paths between the wet basement and the attic.
d. Bats or squirrels.

The common perception that windows are “energy holes” is a bad rap. Since today’s high-solar-gain triple-glazed windows gather more heat than they lose, good windows perform better than an insulated wall. After all, a wall can only lose energy, while windows can gain energy during the day to balance energy lost at night.

Unlike governments in Germany and the U.K., the U.S. government hasn’t yet enacted an energy policy aimed at addressing global climate change. As a result, prices for carbon-based fuels in the U.S. are far lower than in most European countries.

If Americans continue along our current energy path, wrenching climate change is almost inevitable. That’s why many energy experts advise Americans to prepare for the eventual implementation of steep carbon taxes on heating fuel and electricity.

One prominent environmental organization, the Union of Concerned Scientists, has called for an 80% reduction in U.S. greenhouse gas emissions by 2050, and two states (California and New Jersey) have adopted that target as a state goal. The 2030 Challenge, a program endorsed by the American Institute of Architects, sets a goal of implementing energy retrofits designed to reduce energy use by 50% at 1.5 million U.S. homes annually between now and 2030.

In other words, meeting the carbon reduction goals that are necessary to avoid a global climate catastrophe will require almost every U.S. home to under a deep-energy retrofit. In most cases, the work will require walls and roofs to be covered with a thick layer of rigid foam.

The logical time to do this work is when siding or roofing is replaced.

You’re striving to minimize your carbon footprintAmount of carbon dioxide and other greenhouse gases that a person, community, industry, or other entity contributes to the atmosphere through energy use, transportation, and other means. , and your house is energy efficient. Through diligent conservation efforts, you’ve greatly reduced the amount of natural gas and electricity required to run your home.

Bravo! But how does your residential energy budget compare to your transportation energy budget? You may be happy to brag about your low utility bills — but if you’re anything like me, you’re probably a little ashamed of your gasoline budget.

Wind turbines have a hypnotic allure. The Siren call of carbon-neutral electricity has led many environmentalists to dream of owning a backyard wind turbine.

Unfortunately, small wind turbines, unlike utility-scale wind turbines, are rarely cost-effective, even when installed at a good site. Installed at an average site, a wind turbine is little more than an expensive toy.

Manufacturers of small wind turbines are enjoying a boom. Fascinated by the idea of generating their own electricity, many rural homeowners have invested thousands of dollars — sometimes tens of thousands of dollars — in a backyard wind generator.

Buying an inefficient refrigerator is an expensive mistake. But at least the solution is simple: you can always buy a new refrigerator.

If you build an inefficient house, however, you may have an unfixable problem on your hands. Some newly built homes are so poorly designed, sited, and built that it would be cheaper to demolish them and start again than to correct all their flaws.

If you build a small, tight, well-insulated home — in other words, a green home — it won’t need much heat. Since typical residential furnaces and boilers are rated at 40,000 to 80,000 Btuh, they are seriously oversized for a superinsulated home, which may have a heating design load as low as 10,000 to 15,000 Btuh.

Builders have been struggling for decades with the question, “What’s the best way to heat a superinsulated home?” Your solution will depend in part on your answers to a couple of other questions: