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Mineral Wool Insulation Entering the Mainstream

Posted November 6, 2013 11:00 PM by Alex Wilson
Related Categories: Energy Solutions, GreenSpec Insights

Owens Corning’s entry into the mineral wool insulation market with the purchase of Thermafiber, promises a higher profile for this insulation material

Thermafiber's new UltraBatt mineral wool insulation is distributed nationally through Menards. Click to enlarge.
Photo Credit: Thermafiber

I recently reported that a new mineral wool insulation product from Roxul can be readily used in place of foam-plastic insulation materials like polystyrene in certain applications. As part of our ongoing research into how builders and designers can make better insulation choices (see our full webcast and report on the topic), I have new mineral wool developments to report.

First, a little background: mineral wool, variously referred to as rockwool, slagwool, and stone wool, was one of the first insulation materials to be widely produced commercially—starting back in 1871 in Germany.

Insulation Quiz: The No-Foam Challenge

Posted October 31, 2013 2:01 PM by Tristan Roberts
Related Categories: Energy Solutions, GreenSpec Insights, Op-Ed

How well do you know your insulation? Photo: BuildingGreen, Inc.How well do you know your insulation? Photo: BuildingGreen, Inc.A lot of people are questioning the widespread use of foam insulation. Are you familiar with their concerns, and the upsides and downsides of alternatives?

What are all the environmental and health challenges presented by foam insulation products? What about the healthier substitutes? Are they ready for prime time?

These are some of the questions tackled by our new report, and accompanying webcast and course, Choosing and Detailing Insulation for High-Performance Assemblies. Even as more designers and builders are thinking twice about using rigid and spray-applied foam insulation, the alternatives to these products are sometimes misunderstood.

Our pop quiz tests your knowledge of the application-specific challenges and opportunities of these materials. Score yourself, and then read our answers and explanations below.

Formaldehyde-Based Foam Insulation Back from the Dead

Posted October 30, 2013 4:05 PM by Alex Wilson
Related Categories: Energy Solutions, GreenSpec Insights

Urea formaldehyde foam insulation (UFFI) has been out of the spotlight, but going into a lot of buildings—often being referred to as Amino Foam.

Amino Foam is a highly flowable foam that can fill CMU cavities from below—rising as much as 18 vertical feet. Click to enlarge.
Photo Credit: cfiFOAM

In working on major updates and expansions to Insulation Choices: What You Need to Know About Performance, Cost, Health and Environmental Considerations, we’ve had an opportunity to dig into some of the insulation products out there that you don't hear so much about. Some of what we’re found has been surprising.

Anyone remember urea formaldehyde foam insulation (UFFI)? Back in the late 1970s and early 1980s it was the ultimate bad guy of the insulation world. Installed in hundreds of thousands of homes in the U.S. and Canada following the 1973 Energy Crisis, UFFI was found to emit high levels of formaldehyde in some circumstances and shrink considerably, resulting in performance problems.

The Canadian government spent millions of dollars insulating 80,000 to 100,000 homes with this insulation, then spent many more millions uninstalling it when reports of problems emerged. Canada banned the product, as did the Consumer Products Safety Commission in 1982 in the U.S.—though the latter later reversed the ban a year later.

Electric Heat Comes of Age: Installing Our Mini-Split Heat Pump

Posted October 22, 2013 11:48 PM by Alex Wilson
Related Categories: Energy Solutions, GreenSpec Insights

Installing a Mitsubishi air-source heat pump in our new house

The indoor unit of our Mitsubishi minisplit heat pump. Click to enlarge.
Photo Credit: Alex Wilson

Thirty-five years ago, when I first got involved with energy efficiency and renewable energy, the mere suggestion that one might heat with electricity would be scoffed at by those of us seeking alternatives to fossil fuels.

Amory Lovins, founder of the Rocky Mountain Institute, likened using electricity for heating to “cutting butter with a chainsaw.” Electricity is a high-grade form of energy; it doesn’t make sense to use it for a low-grade need like heating, he argued. It made much more sense, we all agreed, to produce that 75-degree warmth with solar collectors or passive-solar design.

So, it represents a bit shift that I’m now arguing that electricity can be the smartest way to heat a house. And that’s what we’re doing in the farmhouse we’re rebuilding in southern Vermont. I should note, here, that all of our electricity is being supplied by a solar array on our barn.

Can A Pending Standard for LEDs Prevent Another Lighting Debacle?

Posted October 16, 2013 10:21 PM by Brent Ehrlich
Related Categories: BuildingGreen's Top Stories, GreenSpec Insights

LED light quality is still not very good, but a new California standard could change that, and prevent another CFL-style consumer rejection.

Cree's TW Series LED Bulb provides impressive 93 CRI light quality yet costs less than $20.
Photo Credit: Cree


LEDs provide some of the most efficacious lighting available today, with some products offering over 100 lumens per watt, or lpw—an incandescent bulb is a paltry 15 lpw. Unfortunately, as consumers know from compact fluorescent lamps (CFLs), which have never been fully embraced, energy efficiency can come at the cost of light quality. Unless something changes, LEDs could become the next CFL, offering energy efficiency at relatively affordable prices, but with poor color and durability and limited dimming ability.

In this month’s Environmental Building News, we look at two products, Soraa’s MR16s and Cree’s TW Series LED Bulb, that offer innovative LEDs with demonstrably superior light quality to standard products (see Soraa: New LED Technology With Improved Color Quality). These lamps, however, are an anomaly in an LED industry where light quality plays second fiddle to efficacy.

Our Deck Is Made from Pallets—But It's Not What You Think

Posted October 15, 2013 9:40 PM by Alex Wilson
Related Categories: Energy Solutions, GreenSpec Insights

Viridian tropical hardwood decking is reclaimed from shipping materials—and it should last decades

Installing Viridian decking on our front porch. Click to enlarge.
Photo Credit: Alex Wilson

We’re moving along with some of the wrap-up work on our house in Dummerston. One of those projects is installing the porch decking on both the front and rear porches and a handicapped ramp up from the garage to the back porch. (We plan to live there for a long time!)

For the decking, we used a product we recognized in our annual Top-10 Green Building Product selection last year.

Resilient Design on the U.N Agenda As It Prepares for Climate Change

Posted October 9, 2013 10:27 PM by Alex Wilson
Related Categories: Energy Solutions

The United Nations, climate change, and resilient design: a day at the U.N. World Habitat conference

The UN assembly hall where we met. Click to enlarge.
Photo Credit: Alex Wilson

The United Nations Human Settlements Programme, or UN-Habitat, is a UN agency focused on human settlements. It was launched in 1978 following a meeting in Vancouver known as Habitat I, and it is mandated by the UN General Assembly to promote socially and environmentally sustainable towns and cities with the goal of providing adequate shelter for all. A follow-up conference, Habitat II, was held in Istanbul, Turkey in 1996, and Habitat III is planned for 2016.

I had the honor of speaking last week at the UN World Habitat Day conference, “Resilient Design for Sustainable Urbanism.” The event was cosponsored by the Consortium for Sustainable UrbanismAIA New York, and the NJIT Center for Resilient Design. (What's resilient design all about? See Resilient Design—Smarter Building for a Turbulent Future.)

It was an amazing opportunity to see the United Nations; I think I was last there over 40 years ago. The UN Headquarters Complex is going through a major $2 billion facelift that includes many exciting green features that are supposed to achieve 50% energy savings, 40% water savings, and a 45% reduction in the carbon footprint…. But that’s not the focus of this column.

Putting the Duct Back in Ductless Mini-Splits

Posted October 3, 2013 4:15 PM by Scott Gibson and Peter Yost
Related Categories: BuildingGreen's Top Stories

A would-be HVAC designer wonders if a ductless mini-split head can be hidden in a closet and connected to conventional ductwork.

This post by Scott Gibson first appeared on Green Building Advisor.

A ductless minisplit head isn't everyone's cup of tea, at least not aesthetically. One reader wonders if he can still get the benefits of a ductless system if he hides the head and makes his own ducts. (Photo: Fujitsu)A ductless minisplit head isn't everyone's cup of tea, at least not aesthetically. One reader wonders if he can still get the benefits of a ductless system if he hides the head and makes his own ducts. (Photo: Fujitsu)A ductless mini-split head isn't everyone's cup of tea, at least not aesthetically. One reader wonders if he can still get the benefits of a ductless system if he hides the head and makes his own ducts.

Ductless mini-splits have a lot going for them. These high-performance air-source heat pumps operate efficiently in much lower temperatures than standard heat pumps, and they don't suffer the same energy losses due to leaky ducts. A tight, well-insulated house may need only one or two wall-mounted heads to maintain comfort, summer and winter.

It's the "wall-mounted" part, however, that not everyone warms up to. As is the case with Jerry Liebler's wife, as Jerry introduced in a recent Q&A post at Green Building Advisor.

Liebler is convinced a Mitsubishi Hyper Heating system would meet his heating and cooling needs. But his wife “dislikes the looks of mini-split indoor units." Liebler's proposed solution is to place the head in a closet along with a small air handler and an outlet duct through the floor.

"A 'shelf' would run horizontally around the mini-split and the outlet duct of the air handler," he writes. "With the closet door closed there would, in effect, be a 'plenum' above the shelf, pressurized by the air handler."

Liebler thinks the air handler's motor would overcome the friction losses of the ductwork. Ducts through the closet floor would be connected to conventional ducts to distribute heated or cooled air.

"Has anyone done something similar?" he asks. "See any problems?"

That's the topic for this Q&A Spotlight.

New Home Proves LEDs Are Ready to Supplant Older Lighting

Posted October 2, 2013 3:57 PM by Alex Wilson
Related Categories: Energy Solutions, GreenSpec Insights

LED lighting has come a long way in a very few years and can now fully supplant incandescent and fluorescent technology

Cree's new CR6 LED downlight for recessed cans.
Photo Credit: Cree

Our electrician was in last week installing lighting in our new home here in southern Vermont. Virtually all of our lighting will be LEDs—the state-of-the-art today in energy-efficient lighting.

LED stands for “light-emitting diode.” It’s a solid-state lighting technology that converts electric current directly into visible light. LED lighting has far higher efficacy (the number of lumens of light output per watt of electricity consumed) than incandescent lighting—which converts roughly 90% of the electric current into heat; only 10% into light.

Most LED lights also have modestly higher efficacy than compact fluorescent lamps (CFLs). The recessed LED lights we installed have an efficacy of 66 lumens per watt, which is not to different from that of CFLs, but LEDs are much more directional than CFLs, so they work better in recessed cans in delivering usable light to where you need it.

WUFI Without Worries: Doing More Good than Harm with Hygrothermal Modeling

Posted October 1, 2013 11:26 AM by Peter Yost
Related Categories: BuildingGreen's Top Stories

Using WUFI for educational purposes? No worries! Predicting performance is trickier, though. (Photo: Evil Erin. License: CC BY 2.0.)Using WUFI for educational purposes? No worries! Predicting performance is trickier, though. (Photo: Evil Erin. License: CC BY 2.0.)WUFI doesn’t kill buildings. Poor design, specification, and workmanship kill buildings.

Last year, BuildingGreen made a modeling software program one of our Top-10 Green Building Products for the first time—the WUFI hygrothermal modeling software from Fraunhofer IBP and Oak Ridge National Laboratory (see “Using WUFI to Prevent Moisture Problems,” an EBN building science primer). We did this because managing moisture as intensely as we manage energy is key to building durability and indoor air quality (IAQ).

But after taking the two-day WUFI training and working with WUFI PRO 5.2 for a while, I began worrying about just how much I might be misusing or abusing this powerful and complex modeling tool.

I thought it made sense to reduce that worry by taking Building Science Corporation’s Advanced WUFI one-day workshop. I would like to tell you that today I am less worried about myself and other dilettante users of WUFI—but frankly, I am now more worried than ever.

That’s because, as with any modeling software, getting something wrong in WUFI can lead to wasted materials and money. It’s one thing to use more energy than you expected, though, and quite another to have your building quietly rotting from the inside out. Getting something wrong hygrothermally can be devastating in terms of overall building durability.

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