Absorption Cooling - The Rise and Fall and Rise - Short #272
HVAC School - For Techs, By Techs
In this short podcast episode, Bryan goes on another history journey, retelling the story of the rise and fall and rise of absorption cooling. 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 gases like ammonia could absorb heat as they evaporated. Instead of compressing the vapor, engineers looked for a way to absorb the heat from the vapor and drive it back out. In 1859, Ferdinand Carré invented a machine that boiled ammonia,...
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Combustion Analysis w/ Tony G.
HVAC School - For Techs, By Techs
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 Fieldpiece—from warehouse worker to training director—Tony brings both technical expertise and real-world application to this 50-minute interactive session focused on the company's CAT 85 combustion analyzer. Tony emphasizes that combustion analysis serves four critical purposes: safety, efficiency, equipment specification verification, and liability protection. He...
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Give Until it Hertz - The Battle Over Frequency - Short #271
HVAC School - For Techs, By Techs
In this short podcast episode, we go back into the history of the trades, namely the battle over frequency (and how each side had to give until it hertz). The low hum of motors is alternating current: electricity moving back and forth through copper 60x per second (in the USA and Canada, at least). In another version of history, that pulse could be 50x per second instead (as in much of the remainder of the world). The forgotten frequency war is the lesser-known sequel to the war of the currents. Tesla's AC power prevailed over Edison's DC, but different motor and generator companies chose...
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Residential vs. Commercial HVAC Sales
HVAC School - For Techs, By Techs
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 discussion tackles head-on the negative perceptions surrounding salespeople while making a compelling case for their essential role in growing and sustaining a trades business. The conversation explores the fundamental differences between...
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When Ammonia Ruled the World - Short #270
HVAC School - For Techs, By Techs
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 chloride, and ammonia. Each one had tradeoffs, but ammonia was the favorite because it was inexpensive, very good at moving heat, and useful because its odor made leaks obvious (although it was toxic and irritated the lungs and mucus...
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Humidity, Airflow, and Refrigeration
HVAC School - For Techs, By Techs
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 HVAC and refrigeration technicians dealing with condensation and moisture issues in commercial refrigeration spaces. The hosts explain why humidity management is critical in grocery environments, where...
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The Finned-Tube Coil - Short #269
HVAC School - For Techs, By Techs
In this short podcast episode, Bryan explores the history of the finned-tube coil, which is what we use for heat exchange in air-source air conditioners and heat pumps. Air-source HVAC systems have copper tubes threaded through thin metal fins. This design was optimized to ensure the greatest possible surface area for heat exchange to occur. However, prior to the finned-tube coil, HVAC coils looked more like plumbing projects with bare copper loops, which were heavy, costly, and inefficient. In the early 1900s, HVAC was essentially plumbing with higher expectations; capacity was dictated...
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Are Two Are Better Than One: Understanding Tandem Compressors
HVAC School - For Techs, By Techs
In this comprehensive episode of the HVAC School podcast, host Bryan Orr sits down with three experts from Copeland to demystify tandem and trio compressor systems. Joining him are Gina Kahle (Multiples Engineering Manager with 12+ years at Copeland), Tyler Daniels (Product Management team member), and James Stevenson (Technical Sales veteran with 28 years of field experience). Together, they provide both the engineering perspective and real-world service insights that technicians need to understand these increasingly common systems. The conversation begins with the fundamentals: tandem and...
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The Tech That Tried to Beat the Compressor - Short #268
HVAC School - For Techs, By Techs
In this short podcast episode, Bryan tells the story of the technology that tried to beat the compressor... and still may someday. We associate cooling with refrigerant... and all the things that come with it, including compressor noise, oil, recovery machines and tanks, leaks, superheat, and regulations. However, there is a means of providing cooling with two pieces of metal and several semiconductors; current runs through it, and one side becomes cold, and the other side becomes hot. This technology is called thermoelectric cooling, associated with the Peltier effect. In 1834, French...
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VRF, Ductless and Humidity Control w/ Roman
HVAC School - For Techs, By Techs
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 emphasizes that successful application of VRF technology in humid environments requires skilled professionals who understand building science, envelope integrity, and proper system sizing. The biggest takeaway? If...
info_outlineIn this comprehensive episode, Bryan Orr sits down with Tim De Stasio to explore the world of comfort consulting and performance contracting in HVAC. Tim, who sold his contracting company to focus on this specialized field, shares his methodical approach to diagnosing home performance issues that go far beyond traditional HVAC troubleshooting. Working primarily in the humid coastal North Carolina market, Tim has developed a thorough process that treats the house as a complete system rather than just focusing on equipment.
Tim's journey into comfort consulting began when he recognized the value of comprehensive home performance testing after seeing the work of practitioners like Michael Housh. His approach combines ethical selling with rigorous testing and data collection, allowing him to stand behind his recommendations with confidence. Unlike traditional HVAC service calls that might only involve checking refrigerant levels, Tim's comfort consultations can take an entire day and involve extensive testing protocols that examine everything from building pressure to thermal imaging.
The conversation reveals how this type of work requires a fundamental shift in thinking - from being an equipment-focused technician to becoming more like a field engineer or building scientist. Tim emphasizes the importance of having repeatable processes and comprehensive checklists, using tools like Safety Culture app to document findings with photos, notes, and annotations. His methodology starts with a detailed pre-visit questionnaire and includes preparing clients for what will be a very different experience from typical HVAC service calls.
Perhaps most importantly, Tim demonstrates how proper diagnostics can lead to ethical sales opportunities. By using tools like blower door tests, thermal imaging, building pressure measurements, and comprehensive system evaluations, he can provide clients with data-driven recommendations prioritized by impact and return on investment. His approach includes a two-week period for analysis before delivering final recommendations, ensuring thoughtful conclusions rather than rushed judgments.
Topics Covered
- The Business Model of Comfort Consulting - How Tim structures his three-pronged business: home performance testing/comfort consultations, HVAC design for contractors, and training
- Preparing Clients for the Process - Using pre-visit questionnaires, YouTube videos, and setting proper expectations for an all-day, disruptive home evaluation
- Comprehensive Visual Assessment - The "hands in pockets" approach, starting with exterior building examination including gutters, downspouts, vent terminations, and moisture issues
- Interior Documentation Process - Room-by-room photo documentation, thermal imaging for missing insulation and thermal bridging, and moisture meter readings
- Crawl Space and Attic Inspections - What to look for in foundation issues, vapor barriers, insulation conditions, and air sealing problems
- Ventilation System Testing - Using flow boxes to measure bathroom fan performance, checking kitchen exhaust, and verifying dryer connections
- Building Pressure Testing Protocols - Stack effect measurements, worst-case depressurization testing, dominant duct leakage assessment, and building pressure balance testing
- Blower Door Testing Procedures - Proper setup, safety considerations, CFM50 vs ACH50 measurements, and using results for Manual J calculations
- Thermal Imaging During Depressurization - Advanced techniques for identifying air leakage paths and problem areas throughout the building envelope
- HVAC System Performance Analysis - Using Measure Quick for comprehensive system evaluation, comparing load calculations to nameplate capacity and delivered performance
- Indoor Air Quality Monitoring - Integration of Haven Central monitors for long-term data collection and analysis
- Report Generation and Client Communication - Creating field reports vs. final reports, prioritizing recommendations by impact and ROI
- Testing Out and Verification - The importance of return visits to quantify improvements and validate work performed
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