Insolation Is Not a Typo for Insulation
In 1993 I took a graduate course in solar energy from Professor Yogi Goswami. It was a great course, and one of the projects we had to do was to compile a whole binder full of solar radiation data for…
The Energy Vanguard Blog
The Sad Joke of Higher Furnace Efficiency Standards
Do you know when the US last raised furnace efficiency standards? It was 1987. Do you know how long the US Department of Energy (DOE) has been trying to change that? At least since 2007. The past eight years have…
A Beautiful Solar Home in Utah Nears Net Zero Energy Use
I'm writing this on St. Patrick's Day so let me tell you a wee bit about the O'Mearas. Kevin and Svetlana O'Meara live in a beautiful home in Utah that's oh-so-close to being a net zero energy home. After I…
The Problem of Getting Air for Atmospheric Combustion Appliances
Remember those two furnaces I showed you photos of last week? You know, the ones that had ducts placed—or taped, in one case—right in front of them to bring them combustion air. I told you it wasn't a good way…
The Energy Vanguard Blog Turns 5
On Saturday, the Energy Vanguard Blog turned 5 years old. It's been an interesting and rewarding journey, and I'm really glad I sat down and started doing it in early March 2010. On Saturday, the Energy Vanguard Blog turned 5…
How NOT to Retrofit a Furnace in a Spray Foam Insulated Attic
A while back I wrote about the incompatibility of putting an atmospheric combustion furnace in a sealed attic. Most often the attic is sealed by installing spray foam insulation at the roofline, thus bringing the attic inside the building enclosure…
Modeling Is Not a Four-Letter Word
Energy modeling has gotten a bad reputation in the home performance world. One conference I've attended has gone so far as to say that it's "outside the sandbox" of topics presenters can cover. They want to see data, not modeled…
The Layers and Pathways of Heat Flow in Buildings
We used to build houses without giving much thought to heat flow through the walls, ceilings, and floors. The main thing was to provide some resistance against wind and rain, and then we'd get a fire going to try to…
Should We Change the HERS Reference Home’s Energy Code?
The HERS Index is a number that gives you a measure of how energy efficient a home is. We can debate how relevant that number is or how accurate is the energy model it's based on, but the fact is…
New Mexico Green Builders Create Water Efficiency Rating System
Energy usually gets top billing in the green building community. It has a huge impact on the environment. We sometimes pay a significant amount for it (although most of us don't pay enough to motivate serious change, but that's another…