A Cold Climate Construction and Energy Blog
This post originally appeared on the Green Building Advisor website.
Testing air leakage in ductwork used for forced air heating and cooling systems has been required since the 2012 IRC code. The 2012 through the 2018 code allowed a testing exemption for all ductwork located inside the building envelope. In other words, if you kept all ductwork inside the thermal and air boundary of the building, no testing was required. That has changed for the 2021 energy code.
Wind: The natural movement of air relative to the planet’s surface.
Washing: A method of cleaning.
Wind Washing: Cleaning using air?
Well, not quite. Wind washing with regards to insulation is the ability of air movement to degrade the effectiveness of an insulation. We will get to that in a little bit. First a quick lesson on how fibrous insulations works.
We use insulation to slow the movement of heat through our building assemblies. Heat will move in three ways, conduction (heat moving when objects are in contact with one another), convection (heat transferred by moving air), and radiation (heat moving through spaces). Fibrous insulations forces heat to move through fibers and small pockets of air, which slows heat movement in both radiation and conduction and prevents heat transmission by way of convection. Continue reading “Construction Design-Wind Washing”
Working as a residential electrician back in the late 1990’s, I remember learning of a new electrical box that we were asked to use on all exterior walls and in the ceilings of unconditioned attic spaces. At the time, they were called “vapor tight” boxes. These boxes were designed to reduce air movement through wall or ceiling cavities by sealing the electrical box to the wall or ceiling air barrier and also to seal the electrical wires where they enter the box. Air will contain at least some water vapor, by air sealing the electrical box, we were also reducing the amount of water vapor that could potentially enter a wall or ceiling. The name “vapor tight” was at least partially correct.
Continue reading “Construction Materials-Airtight Electrical Boxes”
This Article first appeared in the September/October issue of The Journal of Light Construction.
The main purpose of a blower door test is to confirm the integrity and continuity of the air control layer or air barrier. I have a few different options on how to perform a test. Which option I choose is dependent on the reason I am performing the test.
Continue reading “Building Diagnostics-Single Point vs Multi-point Blower Door Testing”
Those of you that have been following this blog for a while know I have been involved with a local project, I’m calling the Barndominium. It’s part conditioned storage and part home, nearly 10,000 square feet in total and a true post and frame structure with posts at 6-foot centers and no structural sheathing anywhere.
Continue reading “Shorts-Blower Door Test Result-Barndominium Project”
2012 was the first year the International Energy Conservation Code required residential construction to pass an air leakage rate test, better known as a blower door test. My area of the country requires the test to be at or below 3 air changes per hour at the test pressure of 50 pascals (ACH50). (Other areas, typically warmer climates require 5 ACH50.) Most new construction in my market has no problem passing the test, but I have had a handful of houses fail, usually the failed tests are by a builder having their first blower door test or the project is a very small home.
Continue reading “Testing-Failed a Code Required Blower Door Test, Now What?”
A modern masonry wood-burning fireplace with a factory built metal Class-A chimney system
Many homes that are (or were) heated with wood or fuel oil, or back in the day, coal, have (or had) masonry chimneys to move the exhaust from burning those fuels to the outside. The chases used to hide these chimney systems are often areas of very high air leakage into and out of a home. With the advent of modern heating equipment that more efficiently burns natural gas and propane, or a system that doesn’t use any burning fossil fuels inside the home to produce heat, such as electricity, the old masonry chimneys have all but gone by the wayside. I have been in many homes, including my own, where the use of this type of chimney system has been discontinued. Mine no longer extends through the roof; it terminates in the attic space. Others have been completely removed. Some new homes being built today still have chimney systems, the masonry chimney is rare, most install metal chimneys or use PVC vents.
This post first appeared on the Green Building Advisor website. Residential Post-and-Frame Construction, Part 5: Insulation and Air-Sealing – GreenBuildingAdvisor
Cavity Insulation
I was brought on the barndominium construction team after many decisions were already in place. The design was, for the most part, finished. Many of the assemblies had been designed, such as the decision to use laminated posts six foot on center with the horizontal wall girts both inside and out. The original plan for the insulation was to use up to seven inches of closed cell spray foam in the walls. I was able to change the insulation strategy with a plan for a more “forgiving” assembly. We chose to go with Rockwool’s 7.25-inch ComfortBatt, which has an insulation value of R-30. Continue reading “Barndominium Part 4-Insulation and Air Control”
This post was first published at www.greenbuildingadvisor.com.
There are many methods used to make a home airtight, it all comes down to one simple rule, continuity. Continuity is easily attained when there’s nothing that penetrates the air barrier. No electrical boxes, plumbing drains and vents or ducts that need to extend from inside a building’s envelope to the outside. Of course, there are times when different things need to extend from inside to outside, like the need for an outside water faucet. But there are also many occasions when different systems end up outside that don’t need to be outside. For example, forced air heating and cooling ducts that leave the conditioned space of the home simply because there was no space to keep them hidden inside the home. Planning a service cavity can help keep most mechanicals inside the building envelope. Continue reading “Construction Design-Service Cavity”
I often hear during energy audits, complaints about windows. Many homeowners feel the windows are cheaply made and replacement will result in substantial energy savings and an increase in comfort for the home. Sometimes the windows are a major cause of comfort problems, more often, the window installation is the issue. This blog post is about three different ways we air seal windows today.
