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 Urbanism, AIA 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.
This post by Scott Gibson first appeared on Green Building Advisor.
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.
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.
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).
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.
I was in New York City over the weekend where I spoke at the Annual Meeting of the Northeast Sustainable Energy Association. What I most relished about the trip was an opportunity to explore a new infill housing project in Brooklyn that’s being built to Passive House standards and may well achieve net-zero-energy performance.
Passive House is a certification system that originated in Germany and has been picking up steam over the past few years in North America. To achieve certification, buildings must have modeled energy performance that does not exceed a very stringent limit for heating and cooling as well as total annual primary energy consumption below a specified threshold.