#Manual J

Tech Tips:

When Ducts Get Too Big
By:Bryan OrrThis tech tip recaps the livestream by the same name, featuring HVAC School contributors Matt Bruner and Adam Mufich, as well as special guests Russ King, Steve Rogers, and Tony Amadio. You can watch that live stream on our YouTube channel HERE. It was a beautiful day outside. The sun was shining, the birds […]
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Size Matters — Industrial “Shortcomings”
By:Jennifer ManzoThis article was written by Jennifer Manzo, an HVAC technician and the founder of HVA-Chicks Coalition. You can find her on social media as @HVAChicksjennifer. Thanks, Jennifer! It’s no secret that the HVAC industry is in the throes of an oversizing epidemic. Instead of stating the obvious, I wanted to take a deep dive […]
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Manual J Field Data: Ducts
By:Matthew BrunerUnderstanding the relationships between ductwork, home comfort, and the load on a house is a complicated and dynamic problem. There are a large number of variables. Some of the data is fairly straightforward, like the other elements of field data collection we have covered so far in this series. Ductwork has different levels of […]
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Manual J Field Data: Windows
By:Matthew BrunerA manual J load calculation will require you to input the U-value for the windows or “fenestrations” on the house. Fenestration is a fancy construction word for window. Figuring out the U-value and SHGC of a window on an existing home is very difficult. But first, let’s dive into what the terms U-value and […]
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Manual J Field Data: Floors
By:Matthew BrunerAdam MufichThere are three types of floors: slab-on-grade, crawlspace, and basement. It should be fairly obvious when you are collecting field data as to what type of floor you are working with. Here is a brief overview of how each type affects a load calculation. Much of the information for this article comes from […]
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Manual J Field Data: Walls
By:Matthew BrunerThis article will cover how to collect field data for walls on an existing home for an ACCA Manual J calculation. In full disclosure, I had never collected any field data for a Manual J before I wrote this article. Many of the methods discussed were suggested by HVAC technicians and contractors in an […]
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The Wide-Narrow-Wide of Manual J
By:Matthew Bruner Starting to work on a Manual J load calculation can feel extremely overwhelming. How do we know what to focus on? What does normal look like? What if I’m way off on something and install way too big or small of a unit? On a practical level, what is the payback or value […]
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Does your Kitchen Exhaust Suck?
By:Adam MufichHave you ever been tasked with installing the exhaust duct for a kitchen hood?  I have, and when doing so, I wondered how to size the duct run correctly. Since I had a basic understanding of how airflow works, I knew that there had to be a limit on the resistance the fan can […]
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Manual D Speedsheet Walkthrough
By:Matthew BrunerBryan recently released a podcast on rules of thumb and how they can really get us in a pickle with sizing ductwork. With that in mind, I thought this might be a good time to do a walkthrough of Manual D from start to finish on a project I just finished up. My good […]
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Podcasts:

Manual J in 15 Minutes?
By:Bryan OrrShelby Breger  Shelby Breger, co-founder of Conduit Tech, joins Bryan Orr on the HVAC School Podcast to discuss her company's innovative lidar-enabled design and sales software tool for HVAC contractors. Conduit Tech's software utilizes lidar sensors in iPads and iPhones to scan homes and create 3D models and 2D floor plans. It overlays […]
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Events:

A Walk Through the Residential Design Series (ACCA Manuals J, S, and D)
By:Ed Janowiak NOTE: If you cannot view the recording, the video may still be processing. The maximum wait time is 24 hours. We apologize for the delay and appreciate your patience.
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ACCA Manuals in the Real World
By:Alex Meaney NOTE: If you cannot view the recording, the video may still be processing. The maximum wait time is 24 hours. We apologize for the delay and appreciate your patience.
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