At the end of my recent blog on Kooltherm rigid phenolic foam insulation, I mentioned that the roof and wall assemblies at an energy retrofit project in Brattleboro, Vermont, were insulated with cellulose by a company called American Installations.
If you know a little building science, you've no doubt seen a lot of problems that occur with air distribution systems. Ducts just don't get anywhere near the attention they deserve in most homes.
I've written about ducts quite a bit here and have shown problems resulting from poor design and installation. We all know how stupid some of those problems are. So today I'm going to talk about a problem that doesn't get nearly enough attention: duct insulation — even when the design and installation are perfect.
Improving the thermal performance of an existing attic is often challenging: workers are faced with narrow cavities, low clearances, and claddingMaterials used on the roof and walls to enclose a house, providing protection against weather. systems that make it hard to achieve desired R-values while still maintaining the necessary drying potential of the assembly.
The house at 81 Chapin Street in Brattleboro, Vermont, is no exception. It’s a 100-year-old wood-framed two-story home that Alex Beck and Candace Pearson are determined to comprehensively retrofit to high performance.
You may have heard or read somewhere that you should run your bathroom exhaust fan whenever you take a shower and then let it run for a while after you're done with the shower. Showers increase the humidity in the bathroom. Sometimes it gets high enough to cause condensation to appear on the mirror and other surfaces in the bathroom. And that can result in mold growth.
So you should always run your bath fan when you shower. Or so they say.
When I woke up Saturday morning, the temperature outdoors was -40 degrees†. The wind chill was -100 degrees! It was just unbelievably, impossibly, inhumanly cold outside. Fortunately, that was on a mountaintop in New Hampshire and not where I was. I happened to have woken up on a mountaintop in North Carolina, where the temperature was a much warmer -3°F.
Julie Paquette has been Director of Energy Management at Yale University for about 6 years. That means the buck stops at Julie’s desk for the energy consumption of over 400 buildings on campus. Yale has a pretty sophisticated approach to energy, including the Yale Facilities Energy Explorer, an energy dashboard system that shows energy consumption and details for every one of those 400 Yale buildings.
Last week I read a nice little article by Steve Baczek about getting buy-in from the various stakeholders involved with building a home. He's an architect who works closely with the people who build the homes he designs. He's also a former U.S. Marine who understands the importance of what he calls "a ladder of leadership and responsibility."
If you live in the world of 2x4 walls, as I do, you may have wondered about the savings you'd get by going to a more robust wall assembly. The typical house in southern climes has 2x4 walls with R-13 insulation in the cavities. The two ways to beef that up would be to add continuous exterior insulation or to go to a thicker wall. But which saves more energy? And how do they compare to the plain old 2x4 wall?
Cold weather is coming back to Atlanta this week, so let’s talk about heat. An increasingly popular way to heat buildings these days is with heat pumps, even in cold climates. But how do they work?
Typical pins on moisture meters are ½ inch long, meaning you can only determine moisture content by weight near the surface of building assemblies and materials (including wood, gypsum wallboard, and concrete). But I often find myself needing to assess moisture content of first condensing surfaces in walls and ceilings or well below the surface of basement slabs.
This article looks at ways to extend the reach of a moisture meter. (For introductory information on moisture meters, see Tools of the Trade: Moisture Meters.)
Because I've written so much about moisture in buildings, I get a lot of questions on the topic. Some are about walls. Some are about the attic. Some are about windows. Some are about the crawl space (which generates the most questions on this topic).
The key to answering a lot of those questions boils down to an understanding of how water vapor interacts with materials. Once you know that, it's easy to see the two rules for preventing damage from humidity.
Building science is an odd subject. Few colleges and universities teach it. The majority of those who work on buildings call themselves engineers, architects, and contractors, not building scientists. And many of those who do invoke the term can explain at least one implication of the second law of thermodynamics (we'll get to that below) but may not know what the other laws of thermodynamics are, why their numbering is so peculiar, or even how many there are. Do you?
We live in this invisible stuff called air. (But of course you knew that.) We pump it into and out of our lungs. We exhaust it from our bathrooms and kitchens. We cycle it through our heating and air conditioning systems. If we're lucky, we live in a home that even brings outdoor air inside as part of a whole-house ventilation system. But we're missing something.