927 Lee Road 268, Valley, AL (706) 773-9274

Zonal Pressure Diagnostics, Part III

This article was originally published by the HVAC School; it has been slightly edited. It is the last in a three-part series. I am picking up where I left off in part 2 of the series, where I discussed how a pressure reading from an attached zone indicates only the ratio of the collective size of the leaks between the zone and the envelope with relation to the collective size of the leaks between the zone and outdoors (and vice versa). In other words, a zonal pressure diagnostic (ZPD) reading by itself does not tell us if a zone is…


Home Data Logging

This is the first post in a four-part series covering the topic of data logging in terms of Types of Monitoring, Products and Performance, and Indoor Air Quality. “Data logging” is a term used to describe the recording of information about a home’s interior conditions—such as temperature and humidity—using a little device designed for this purpose. (I am partial to Onset Hobo loggers.) Logging allows us to solve several types of problems that are hard to analyze. We can see things that happen only late in the evening or early in the morning—the times when heating and air conditioning systems…


What Corporate Net-Zero Pledges Really Mean

You’ll probably hear the term “net-zero emissions” a lot over the coming weeks as government leaders and CEOs, under pressure, talk about how they’ll reduce their countries’ or businesses’ impact on climate change. Amazon, for example, just announced that more than 200 companies have now joined its Climate Pledge, committing to reach net-zero emissions by 2040. But what does net-zero emissions actually mean? “Zero emissions”—without the “net” caveat—means emitting no greenhouse gases. “Net-zero emissions” has more wiggle room. It’s like balancing a checkbook. The country or company cuts most of its emissions through efficiency and clean energy, then offsets the…


The BS* + Beer Show: Construction Instruction

This episode of the BS* + Beer show features Gord Cooke, Mark LaLiberte, and Justin Wilson—the three principals of Denver-based Construction Instruction—explaining their approach to educating residential building professionals. They talk about the impetus for starting the program and dive deep into the value of experiential training, pointing to the efficacy of hands-on demonstrations—their primary teaching tool. They talk energetically about Ci Live, a turbo-charged, in-depth program covering applied building science, climate-specific construction, building enclosure details, HVAC mechanicals, drawing plan optimization, and more. If you care about building better homes and want to learn how to do it, watch this…


Widow’s Walk: An Inside Look at an Uncommon Roof Feature

Builder-at-large Justin Fink is on the job with J&J Custom Builders to take a look at some unique roof framing. Here’s what he had to say about it. The flat section is just a big box joined by double LVL beams, with regular joists going down by blocking to stiffen everything up. In the corner, there are valley rafters for the hip roof that go all the way down to the wall plate. In all four corners, there’s a little birdsmouth at the top. You don’t need any posts here going down to the floor because all four corners are…


How to Insulate a Short Attic Kneewall

Back in my home-performance contracting days (2004 to 2007), I spent a lot of time in unconditioned attics and crawlspaces. First, I was there to find problems. Then, if the homeowners hired me, I’d go in and do air sealing, insulating, duct sealing, duct repairs, crawlspace encapsulation, and sometimes other jobs. The photo above shows one of the many problems I found and fixed in a house in the Atlanta area in 2006. In the living space below the attic, there was a change in ceiling height, resulting in a short attic kneewall. As you can see, it is uninsulated.…

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