Replacing Residential HVAC Equipment With “Predictable Results”
When replacing a furnace or air handler for a customer, there is nothing worse than starting up the equipment and having it sound like the latest SpaceX rocket taking off. You insert your static pressure probes into the duct, and your stomach drops as you read the numbers.  You realize the new high-end system you’ve […]
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Manual D Speedsheet Walkthrough
Bryan 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 friend […]
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Why Measuring Static First Isn’t Always Productive
There is a big move in residential and light commercial HVAC toward measuring static pressure regularly during commissioning, service, and maintenance. Don't get me wrong… Measuring static pressure is VERY important. The challenge comes in when techs begin taking measurements without understanding where to take them, what they mean, or worse: they use measurements as […]
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Use Static Pressure Responsibly
The topic of static pressure comes up frequently in HVAC, and it’s sometimes presented as a test that can be all-knowing and insightful about what is happening with regard to airflow in a system. To use static pressure responsibly, we need to understand what it really is and what it means for an HVAC system. […]
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Static Pressure – Why Measure It?
This article was written by Neil Comparetto. Neil is one of the smartest and most thoughtful techs I know online. Thanks, Neil. Why measure static pressure? Because it's fun. I enjoy drilling holes in things. I rarely leave a house without drilling a hole in something. I also believe it’s an essential step to commissioning […]
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Total External Static Pressure (TESP): A Basic Review
Probably the most popular measurement method for indirect airflow readings is total external static pressure (TESP). A dual-port manometer or two Bluetooth single-port manometers are essential to the HVAC technician toolbag. Here’s a quick review of TESP, why it’s important, and how to make the measurements. TESP is a pressure reading of the “balloon” pressure […]
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How to Use a Manufacturer Fan Table and Why They are Important
Many installers and service technicians know how to read and use a manufacturer fan table, but this is a quick review with a few extra tips for newer techs. It’s also a good reminder to senior technicians about how this easy-to-use practice can also be easily abused. At installation, properly setting up airflow is imperative to the […]
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The “5 Pillars” of Residential A/C Refrigerant Circuit Diagnosis
Suction pressure, head pressure, subcooling, superheat, delta T. Taking all five of these calculations into account on every service call is critical. Even if you must do further diagnostic tests to pinpoint the problem, these five factors are the groundwork before more effective diagnostics can be done. I would also add static pressure as an […]
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Some Important Terms to Know
In my recent classes with my employees at Kalos, we've been going over finding target pressures and temperatures for an air conditioning system. The goal has been to get techs to have “target” readings in mind before they start connecting tools. This step is an important part of being able to “check a system without […]
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