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3 Ways to Reduce Compression Ratio in a Heat Pump
Best Practices to Conserve A2L Refrigerants in a Shortage
High-Pressure vs. Low-Pressure Shell Scrolls: A Deeper Dive
Should the Float Switch Break R or Y?
Don’t Drive Drowsy
Flex Ducts: Peeling Back the Layers
Solving Delta T
Donโt Fall for Unsafe Practices: Heights in HVAC
Non-Invasive Testing: A Smarter Approach to System Diagnostics
Superheat in Heat Mode: Why Heat Pumps Get Weird – Short #274
What We Learned From NCI Duct / Balancing Training
HVAC Systems for Architects: Making Sense of the Alphabet Soup – Short #273
Sizing Breakers and Conductors (for HVAC) โ Have Things Changed?
Absorption Cooling – The Rise and Fall and Rise – Short #272
Combustion Analysis w/ Tony G.
Residential vs. Commercial HVAC Sales
When Ammonia Ruled the World – Short #270
Humidity, Airflow, and Refrigeration
#hvac
Tech Tips:
Weโve talked about compression ratio a lot over the years. Compression ratio is the number you get when you divide the absolute head pressure (PSIG + 14.7) by the absolute suction pressure (PSIG + 14.7). It measures the efficiency of a compressor, and lower numbers indicate that the compressor is moving more refrigerant while consuming […]
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If you own your HVAC company or are involved in management, you may have realized that our industry is currently facing a shortage of new A2L refrigerants, particularly R-454B and R-32. Our own company has faced limited availability and long lead times, mainly due to supply chain disruptions and the increased demand now that our […]
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I want to share something that came up in a recent discussion with Roman Baugh about VRF systems, and it made me realize I might have had a blind spot regarding scroll compressor designs. We were talking specifics, and he brought up high-pressure shell compressors. My immediate thought was, “Hold on, aren’t scrolls low-pressure shell […]
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There are three things we never discuss at the dinner table: religion, politics, and which wire to break with your float switch. A float switch fills with water whenever there is a drain backup, and it breaks power to one of the low-voltage wires. We clearly want the HVAC system to stop producing more condensate, […]
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Being in an industry that requires a lot of travelโlocal or regionalโcan be a great thing for people who enjoy driving. It also comes with several more risks and opportunities for roadway accidents than someone who just has a round-trip commute to a single location every day.ย Weโre all aware of the issues of texting behind […]
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A few times in the past, weโve heard the phrase โthe house is the biggest ductโ because of the way air moves through it. Well, we can take it a step further and see that there are similarities that go just beyond air movement.ย A building has several layers to keep things like moisture, heat, and […]
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Delta T is the difference in temperature between two points of the same medium. It is commonly used by scientists and engineers to analyze the amount of heat transfer in a system. In general HVAC terms, it is the measurable change in temperature between an air input and air output. However, it could also be […]
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DISCLAIMER: HVAC School is NOT an official OSHA safety training resource! Although we provide safety tips in good faith, neither this tech tip about the hazards of working at heights nor any other training on our website is a substitute for safety training from an authorized OSHA training source. Many things may deter people from […]
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This tech tip about non-invasive testing comes from a post in the HVAC School Facebook group by Ed Janowiak. Ed is the Manager of HVAC Design Education at ACCA, a longtime friend of HVAC School, and an educator who does a lot of great work for the industry. Thanks, Ed! This past Thursday, I taught […]
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Videos:
Podcasts:
๏ปฟ๏ปฟ In this short podcast, Bryan answers a listener-submitted question and explains why heat pumps get a bit weird: when it comes to superheat in heat mode. He also explains how we can move heat from outdoors to indoors, even in temperatures below freezing (cold temperatures just have less heat, not zero heat). In order […]
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๏ปฟ In this engaging and informative episode, Bryan sits down with Elliot to discuss his recent training experience with the National Comfort Institute (NCI), covering two intensive courses on duct system optimization and residential air balancing. The conversation offers valuable insights for HVAC professionals looking to improve their technical skills and provide better service to […]
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๏ปฟ๏ปฟ In this short podcast, Bryan answers a question submitted to HVAC School by an aspiring licensed architect who wanted to learn more about the many different types of HVAC systems. The three main buckets of HVAC systems are air-to-air, water-source, and air-to-water. Air-to-air systems move air around to remove heat from one space, and […]
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๏ปฟ๏ปฟ In this essential episode, Bryan Orr sits down with Elliot, the residential install supervisor at Kalos Services, to unpack a critical issue that’s causing confusion among HVAC technicians, electricians, and inspectors alike: the new standards for breaker and conductor sizing on inverter-driven equipment. The conversation was sparked by Elliot’s frustrating experience of having two […]
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๏ปฟ๏ปฟ In this short podcast episode, Bryan goes on another history journey, retelling the story of the rise and fall and rise of absorption cooling.ย Some of the first HVAC/R engineers cooled buildings with fire; they used absorption refrigeration, which ran on heat instead of electricity. In the early 1800s, French scientist Michael Faraday showed that […]
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๏ปฟ๏ปฟ In this comprehensive training session from the symposium, Tony Gonzalez, Training Director at Fieldpiece, delivers an engaging and practical guide to combustion analysis for HVAC technicians. With 25 years of experience at Fieldpieceโfrom warehouse worker to training directorโTony brings both technical expertise and real-world application to this 50-minute interactive session focused on the company’s […]
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๏ปฟ๏ปฟ In this candid conversation, Nathan and Bryan dive deep into the often-misunderstood world of sales in the construction and HVAC trades. Nathan, who has transitioned from fieldwork to spending roughly 60% of his time in sales, offers a unique perspective on why sales professionals are necessary despite the skepticism they face from tradespeople. The […]
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๏ปฟ๏ปฟ In this short podcast episode, Bryan takes us on a history journey back to when ammonia ruled the world. In the mid-1800s, before R-12, many inventors and scientists experimented with vapor-compression refrigeration systems to make ice. They used a variety of refrigerants in their patents, including ether, ethyl ether, carbon dioxide, sulfur dioxide, methyl […]
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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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