Books on Insulation and Energy-Efficient Building
Book Reviews: Alex Wilson’s new insulation guide and JLC’s new book about building superinsulated homes
Two new books that might interest green builders recently caught my eye: The BuildingGreen Guide to Insulation Products and Practices by Alex Wilson and The JLC Guide to Energy Efficiency by the editors of The Journal of Light Construction.
Full disclosure: I was a minor participant in the creation of both books. At Wilson’s request, I reviewed portions of his manuscript before publication and provided feedback. I also wrote several of the articles appearing in the JLC book.
Heat transfer basics
Alex Wilson’s book, Insulation: The BuildingGreen Guide to Insulation Products and Practices, is a short (83-page) electronic book that sells for $129. (BuildingGreen members can purchase the book at a $30 discount.)
Wilson’s downloadable report seems aimed at designers and architects rather than at builders or insulation contractors. The book includes no installation tips.
Wilson provides basic background information on the three modes of heat transfer, as well as solid information on R-valueMeasure of resistance to heat flow; the higher the R-value, the lower the heat loss. The inverse of U-factor. , U-factorMeasure of the heat conducted through a given product or material—the number of British thermal units (Btus) of heat that move through a square foot of the material in one hour for every 1 degree Fahrenheit difference in temperature across the material (Btu/ft2°F hr). U-factor is the inverse of R-value. , and air leakage. The guide also includes separate articles on many types of insulation, including batts, rigid foam boards, and spray foam products.
Much of the information in this guide is written for those who are interested in green construction; for example, there is detailed information on the possible environmental effects of phenol formaldehydeChemical found in many building products; most binders used for manufactured wood products are formaldehyde compounds. Reclassified by the United Nations International Agency for Research on Cancer (IARC) in 2004 as a “known human carcinogen." and halogenated flame retardants.
A few quotes will provide a sense of the topics featured in this guide:
- “Heat flow moves in three ways — conductionMovement of heat through a material as kinetic energy is transferred from molecule to molecule; the handle of an iron skillet on the stove gets hot due to heat conduction. R-value is a measure of resistance to conductive heat flow., convection, and radiation — and the test for R-value measures all three. … By capturing the effect of all three modes of heat transfer through materials, R-value gives us a great way to compare insulation products.”
- “Given the uncertainty about future costs of energy and the security of having a building that will maintain livable conditions in the event of extended power outages or interruptions in heating fuel, it often makes sense to invest significantly more in energy efficiency than a simple ‘payback’ analysis might suggest.”
- “While all [foam] insulation being manufactured or sold in North America today is safe for ozone, there are significant differences relative to global warming potential (GWP).”
- “It is not unusual for rigid insulation to be removed from low-slope roofs during re-roofing. Building reuse and materials salvage organizations sometimes stock this insulation; as long as it hasn’t absorbed moisture or been damaged by UV radiation, it should work fine in another application.”
- “The benefit from radiant barriers is inversely proportional to the amount of thermal insulation in place. With more insulation (fiberglass, cellulose, etc.), the radiant barrier will have less effect. Most claims of significant benefit from radiant barriers assume very little insulation. In most cases, it makes more sense to install additional insulation than to install a radiant barrier.”
Wilson doesn't just describe the insulation products on the U.S. market; he also provides guidance. Readers of Environmental Building News are probably already aware of Wilson’s fascination with FoamGlas, also known as cellular glass insulation. In a table listing material recommendations, FoamGlas is BuildingGreen’s “top pick” for insulating slabs and the exterior of foundation walls. Since an R-19 layer of this rarely used insulation has an installed cost of $6.20 to $7.50 per square foot, few builders are likely to make the same pick as Wilson.
When it comes to residential walls and attics, however, Wilson’s advice is less controversial: he’s all in favor of cellulose.
Thorough but somewhat academic
Wilson’s insulation guide is solid and dependable. Its main flaw is its perspective: the book is academic, showing few signs of job-site knowledge. For example, Wilson devotes too many pages of his insulation guide to obscure insulation products, including perlite, wool, FoamGlas, gas-filled panels, and vacuum insulation panels.
The space devoted to these marginal products could have been better devoted to information on installation methods and installation problems. After all, designers really shouldn't specify cellulose insulationThermal insulation made from recycled newspaper or other wastepaper; often treated with borates for fire and insect protection. (for example) unless they have a thorough understanding of how cellulose is installed.
In fact, if a designer doesn't know how different insulation products get installed, it’s hard to design any building. Far too often, architects finalize a building's shape before they have a good idea of how the building will be insulated — a classic example of cart-before-the-horse design.
This guide would also benefit from a section on installation problems — for example, problems arising from poorly installed fiberglass batts or spray-foam jobs with lingering odors — to give designers information that would help them do a better job of specifying insulation.
Although Wilson hasn't produced a complete guide to insulation, the report is a valuable reference work that pulls together a lot of basic technical information on insulation products. Many designers will be glad to have it handy as they choose which insulation to specify.
The JLC Guide to Energy Efficiency
The JLC Guide to Energy Efficiency is an anthology of articles previously published in The Journal of Light Construction. (That fact has been thinly disguised by changing most of the articles’ titles.)
I know what you’re thinking —“I subscribe to JLC already, so why buy the book?” When I first saw the book and realized that its contents had been previously published, that’s what I thought. But when I sat down and flipped through the pages, I changed my tune.
As you check out the collected articles, you’ll realize, “Oh, I forgot about that article. That was a really good one.” Once you’ve got this book on your shelf, you won’t have to thumb through ten years of back issues to find the gems. They’re all here.
Here’s a list of just some of the articles in the book — all classics:
- “Blower-Door Testing,” by David Keefe
- “Troubleshooting Spray Foam Installation,” by Mason Knowles
- “Super-Insulated Slab Foundations,” by Alan Gibson
- “Building a High-Performance Shell,” by David Joyce
- “REMOTE Walls,” by Thorsten Chlupp
- “Tight and Efficient Double Stud Walls,” by Dan Kolbert
- “Attic Ventilation Details,” by Gordon Tully
- “Insulated Cold Roof Retrofit,” by Dan Perkins
- “Simple Exhaust Ventilation for Tight Houses,” by Andrew Shapiro
- “Installing a Heat-Recovery Ventilator(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. ,” by David Hansen
- “Effective Air Sealing in Existing Homes,” by Bruce Torrey
- “Retrofitting Exterior Insulation,” by David Joyce
- “Designing Overhangs for South Glass,” by Jerry Germer
Many of the authors featured in this book — including Thorsten Chlupp, Paul Eldrenkamp, Dan Kolbert, Joe Lstiburek, and Mike Rogers — participate regularly in discussions on the GBAGreenBuildingAdvisor.com website.
Like all JLC articles, the articles collected in this book are generously illustrated with color photos and Tim Healey’s famously clear illustrations.
This book is reasonably priced at $39.95; if purchased online, it costs only $29.95 . Buy it; you’ll be glad you did.
Last week’s blog: “European Products for Building Tight Homes.”
Dec 2, 2011 10:53 AM ET
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Dec 13, 2011 12:44 AM ET