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Does Mass or Volume Move Heat?
How to Reduce Indoor Humidity
Understand Dew Point and Absolute Moisture, The Right Side of the Psych Chart
How Attic Designs Need to Account for Heat and Moisture
Set Inverter Technology Up for Success in Humid Climates
Why Airplanes Fog Up Before Takeoff
Why the Sauna Feels Hotter When You Throw Water on the Rocks
Itโs All Relativeโฆ Humidity
Not All CFM Are Created Equal
Is 400 CFM per Ton Always Right? w/ Ty
Behind the Drywall โ The Psychrometrics of a Hidden Moisture Failure – Short #298
The House Always Wins! A Class On Building Science Basics – Short #294
Humidity, Airflow, and Refrigeration
VRF, Ductless and Humidity Control w/ Roman
Psychrometrics and the Magic Line – Short #265
Leaky Ducts = Sweaty Houses – Short #256
ERVs – What You Need To Know w/ Dr. Bailes
Santa Fe Talks Dehumidification at AHR 2025
#humidity
Tech Tips:
I once heard someone say, and I have since repeated many times, that BTUs ride on the back of cubic feet of air (CFM). As I’ve learned more, I’ve come to the conclusion that the weight or mass of the air passing over the evaporator coil is far more important to understand both in terms […]
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Sometimes I beat around the bush too much in these tech tips, so let’s get down to the nitty-gritty! (As Nacho Libre would say.) Humidity inside a home should be maintained between 30% and 60% relative humidity. I like to shoot for 50% in humid climates when possible (and by possible, I mean financially feasible […]
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Let’s first state the obvious. Most techs are intimidated by psychrometric charts and Mollier diagrams. We JUST ARE. While there are some pretty complicated formulas that back up these diagrams, using them isn’t thatย big of a deal once you understand the different elements and then focus on one at a time. BUT WHY DO YOU […]
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This tech tip was heavily inspired by one aspect of Rick Simsโs 2021 HVACR Training Symposium session titled โConductsation.โ The entire presentation is worth a watch, but the advice in โConductsationโ and this tech tip are tailored to hot, humid climates. The contents of this tech tip may NOT work for colder climates. Dr. Allison […]
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This tech tip about humidity control, particularly as it relates to VRF systems and others that use inverter technology, is a companion piece to a podcast episode with Roman Baugh. You can listen to that podcast episode HERE. Those of you who work in humid climates and install or repair ductless systems are probably well […]
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Every once in a while, especially on humid days, youโll sit on an airplane waiting for takeoff and see fog pouring from the ceiling vents like a low-budget concert. Someone always panics and asks if somethingโs on fire. Itโs not smokeโitโs condensation. Youโre looking at thermodynamics and psychrometrics in action. So, why does it happen, […]
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I admit it, I’m a sauna guy now. The ones at the gym are pretty gross, so I got a small one at home because I guess Iโve missed sitting in attics or something. If youโve ever sat in a traditional sauna, you know the drill: the heatโs already intense, and then you or someone […]
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Floridaโs got a lot of great qualities: some pretty neat wildlife, beaches all around, and theme parks. On the flip side, Florida also has hurricanes and a lot of humidity. As much of a pain as it might be for residents and contractors alike, humidity is one of my favorite topics.ย We see relative humidity (RH) […]
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Weโre in the business of moving heat, but we have to move air to accomplish that. We use CFM (cubic feet per minute) to quantify the air we move over the indoor coil, and it helps to imagine hundreds of 1โx1โx1โ boxes of air moving over that coil each minute. (After all, 400 CFM is […]
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Videos:
Podcasts:
๏ปฟ๏ปฟ๏ปฟ 400 CFM per ton is usefulโuntil it isnโt. In this episode, Bryan and Ty take on one of the tradeโs favorite rules of thumb. It can be a reasonable starting point for many systems under moderate, near-sea-level conditions, but it is not a universal target. Proper airflow depends on actual delivered capacity, sensible and […]
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๏ปฟ๏ปฟ๏ปฟ In this short episode, Bryan and Roman talk about the psychrometrics of a hidden moisture failure… behind the drywall. Roman had an indoor air quality and mold assessment in his own home, and he learned that there were active mold spores in his home; he shares what he learned from the experience. Roman had […]
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๏ปฟ๏ปฟ๏ปฟ In this short episode from the Bry-X stage of the 7th Annual HVACR Training Symposium, Tessa Murry gives a class on building science basics: The House Always Wins! Tessa is a building scientist who works with TEC. Tessa’s class is about how the house puts HVAC contractors in difficult situations. When people have indoor […]
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๏ปฟ๏ปฟ๏ปฟ In this episode of the HVAC School podcast, Bryan and Nathan dive deep into the challenges of humidity control in grocery stores and other refrigerated environments. While the conversation takes several entertaining detours (including discussions about morning radio shows, Indian weddings with elephants, and imaginary lava-heated homes), the core content provides valuable insights for […]
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๏ปฟ๏ปฟ In this comprehensive episode, Bryan and Roman dive deep into one of the most challenging topics in modern HVAC: making VRF (Variable Refrigerant Flow) and ductless systems perform effectively in humid climates like Florida. The conversation tackles a common misconception that inverter-driven equipment automatically handles humidity well simply because it can “turn down.” Roman […]
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๏ปฟ๏ปฟ In this short podcast episode, Bryan talks about psychrometrics and the magic line inside a messy-looking chart. The psychrometric chart is a key tool for understanding the relationship between air and water. “Psychrometric” comes from the Greek roots for “cold” and “measurement.” As such, a tool called the psychrometer (with paired wet-bulb and dry-bulb […]
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๏ปฟ๏ปฟ In this short podcast episode, Bryan explains how leaky ducts can lead to sweaty, uncomfortable houses. Moisture issues are common all across humid and “green-grass” climates in the United States. Hot, unconditioned attics and crawl spaces also often have high dew points, which can cause moisture problems in those spaces. Plants also release moisture, […]
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๏ปฟ๏ปฟ In this episode of the HVAC School podcast, host Bryan sits down with building science expert Allison Bailes to dive deep into the world of Energy Recovery Ventilators (ERVs). The conversation explores the critical role of ventilation in modern homes, highlighting how ERVs have become an essential component of maintaining indoor air quality and […]
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๏ปฟ๏ปฟ In this insightful discussion at AHR 2025 in Orlando, Bryan connects with Nikki Krueger from Santa Fe dehumidifiers, exploring the evolution and importance of whole-house dehumidification in modern HVAC systems. Nikki, who has spent 20 years in the indoor air quality industry, shares her journey from a public relations background to becoming deeply involved […]
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