Building HVAC Science

Exploring the science, people, and practices shaping better buildings. The Building HVAC Science Podcast dives deep into the technical and human sides of heating, ventilation, air conditioning, and building performance. Hosted by industry veteran Bill Spohn, CEO, and co-host Eric Kaiser, Industry Engagement Manager at TruTech Tools the show brings together decades of hands-on expertise with a passion for advancing the craft of HVAC. With nearly 240 episodes and counting, the podcast features conversations with contractors, distributors, manufacturers, educators, and thought leaders across the HVAC and building science communities. Each episode blends practical knowledge with bigger-picture insights, helping professionals stay ahead of trends, sharpen their skills, and build stronger businesses. Our topics range from: • New tools, technologies, and field practices. • Case studies and lessons learned from real-world contractors. • Building performance, comfort, and indoor air quality. • Industry innovation, workforce development, and the human stories behind the work. Whether you’re a technician in the field, a business owner, a manufacturer, or simply curious about the science of how buildings breathe and perform, Building HVAC Science connects you with the knowledge and voices moving the industry forward. * Listen on Apple Podcasts, Spotify, or wherever you get your podcasts. This show is a production of TruTech Tools®, LTD.

EP259 Donkey Wrangler to HVAC Whisperer: Brad Adcox on Fundamentals That Win (January 2026) 02/27/2026

EP259 Donkey Wrangler to HVAC Whisperer: Brad Adcox on Fundamentals That Win (January 2026) Pithy quotes “Your product can be great, but if you’re hard to work with, nobody’s going to buy it.” “Take a deep breath, go back to the fundamentals, and ask: what’s the biggest value I can add today?” “You’re allowed to say, ‘I don’t know. I’ll figure it out for you.’ People respect that more than the runaround.” Brad Adcox joined the Building HVAC Science podcast with Bill and Eric and, within minutes, earned the unofficial title “donkey wrangler” after sharing a story about his donkey. The laughs kept coming, including a side quest into hobby-farm life on a 40-acre “family compound” outside Dallas with cows, donkeys, mini horses, and a long-running plan by Brad’s dad to eventually acquire a camel. The banter was fun, but it also set the tone for who Brad is: practical, observant, and very people-focused. Brad’s HVAC background runs deep and wide. He grew up around wholesale, started at Winsupply in the warehouse and as a delivery driver, then moved through outside sales and even a stint selling and building Cisco server infrastructure. He eventually joined SUPCO, helped scale territory coverage and rep networks, and was part of launching TradeFox, the influencer-inventor program that surfaced a pile of real-world products, including the magnetic umbrella that Bill notes TruTech sold in big numbers. Brad later spent time at NAVAC teaching fundamentals like pulling a proper vacuum, and today he’s in a “free agent” phase, running consultant-style sales and service training for contractors in the DFW area. The core of Brad’s message is fundamentals, especially customer service and relationship transfer. He’s worried the industry is headed for a knowledge cliff as experienced wholesalers, reps, and counter people retire without passing down relationships or practical know-how. He also sees a drift toward “parts changers” and automated, text-only customer interactions that reduce real human connection. In his local classes, he pushes techs to slow down just enough to add value: communicate like a neighbor, do a fuller system check while you’re already there, explain what you looked at, and offer small, memorable extras. He’s also blunt about wholesale basics: greet people when they walk in, be willing to say “I don’t know, but I’ll find out,” and stop hiding behind “that’s just Facebook” when customer sentiment is being broadcast publicly. Brad’s: LinkedIn: This episode was recorded in January 2026. /episode/index/show/buildinghvacscience/id/40128535

EP258 Live From AHR 2026: Tools, Tactics, and Trade Stories From the Show Floor With the Team from TruTech (February 2026) 02/20/2026

EP257 From Rockets to Heat Pumps: Shreyas Sudhakar on Scaling Quality HVAC (January 2026) 02/13/2026

EP257 From Rockets to Heat Pumps: Shreyas Sudhakar on Scaling Quality HVAC (January 2026) Pithy quotes “We do our job well if the homeowner forgets about us, because the system just works.” “The bar is so low in some homes that doing a quality install can genuinely change someone’s life.” “The best way to learn is crawling in the crawl space behind a great technician and handing them tools.” Semi-famous quote that fits our theme “Stay hungry, stay foolish.” © Steve Jobs Shreyas Sudhakar joined the Building HVAC Science podcast to talk about his path from rocket propulsion engineering to building high-quality heat pump installs in California. Bill and Eric found him through his thoughtful LinkedIn posts, and Shreyas shared that a friend’s relentless heat-pump evangelism finally pushed him to look deeper. Once he did, the tech clicked. He realized HVAC and rockets share the same core idea: moving energy through systems, and the math is not as far apart as it sounds. What really pulled him in was the homeowner experience. After talking with homeowners on Nextdoor and Reddit, and even calling contractors for quotes himself, he kept hearing the same frustrations: heat pumps feel expensive, contractor advice is inconsistent, trust is low, and myths like “heat pumps don’t work in the cold” still show up, even in mild California climates. Shreyas’ view is simple: most homeowners do not care what the equipment is called. They care about comfort, noise, bills, and safety, and the best outcome is when the system is so reliable they barely think about it. Shreyas now runs Vayu, a lean heat pump installation company operating with vetted subcontractor partners, while his Heat Pumped newsletter and podcast focus on education for homeowners, technicians, and policy folks. Vayu handles the end-to-end process, from load sizing and equipment selection to permits and rebates, while partner shops focus on the craft of installation. His definition of success is not just a happy install day, but a customer still loving the system a decade later, and technicians thriving because the model removes desk work and supports quality work at scale. Shreyas’ LinkedIn: His websites: & HeatPumped Newsletter sign up: Heat Pumped Podcast: This episode was recorded in January 2026 /episode/index/show/buildinghvacscience/id/39900145

EP256 The Woodstock of HVAC: Why This Symposium Hits Different With the TruTech Team (January 2026) 02/06/2026

EP256 The Woodstock of HVAC: Why This Symposium Hits Different With the TruTech Team (January 2026) Episode quotes: “What you put into this, you get out of this in multiples.” “It’s not about sales. It’s about learning, relationships, and leaving your ego at the door.” “Use AI responsibly, but keep the humans involved. The humans are what keep it honest.” In this episode of the Building HVAC Science Podcast, Eric Kaiser, Bill, and the TruTech Tools crew (Billy Spohn, Ginny Hebert, and Josh Crawley) recap their trip to the 7th Annual HVACR Training Symposium in Ocoee, Florida. Josh and Ginny share first-timer impressions: early-morning booth setup, instant attendee engagement, a surprisingly family-friendly outdoor vibe (kids and dogs everywhere), and the general “people are here to learn, not to get sold to” energy. The group talks about how rare it is to see a community where respect and curiosity are the default. They also dig into the most memorable moments and crowd magnets: the GRIT Foundation dunk tank fundraiser, Jim Bergmann’s talk on using AI responsibly (in conjunction with real measurements), and hands-on booth favorites like the Shaeco fin straightener demo, the RETROTEC“air tracer,” and continued interest in specialized tools like the TrueFlow grid and torque screwdrivers. Billy highlights a renewed surge of questions around combustion analyzers and why the industry seems to cycle back to them, while Eric frames it simply: you cannot fix what you cannot see. To close, everyone answers the question of why the symposium matters, in person or virtually. The consistent theme is relationships, peer learning, and a network that lasts long after the event. Bill caps it with a challenge: what you put into this community, you get back in multiples, and it can genuinely be career-changing. Symposium link: ELK’s LinkedIn: Josh’s LinkedIn: Ginny’s LinkedIn: Billy’s LinkedIn: Bill’s LinkedIn: This episode was recorded in January 2026. /episode/index/show/buildinghvacscience/id/39983720

EP255 Beyond Manual J: The Heat Balance Future of Residential Load Calculations With Tony Amadio (December 2025) 01/30/2026

EP255 Beyond Manual J: The Heat Balance Future of Residential Load Calculations With Tony Amadio (December 2025) Notable quote from the episode: Make it as simple as possible, but not simpler. In this episode, Eric Kaiser sits down with mechanical engineer Tony Amadio, the founder of True Loads, to talk about what actually makes residential load calculations succeed or fail in the real world. Tony shares how his work is split between builders, architects, project managers, and HVAC contractors, and why the biggest early battle was simply getting people to trust results that pointed to smaller equipment. He explains how he quickly learned from feedback loops in production housing, including what happens when people “over-vent” tiny spaces like closets and bathrooms, accidentally stealing airflow from bedrooms where it matters. Tony walks through his approach to receiving plans, emphasizing the importance of nailing down the building envelope inputs (windows, insulation, attic conditions) and getting key assumptions in writing. On renovations, he emphasizes that uncertainty is normal, so you lean on photos, field verification, and practical guidance to keep the model honest. They dig into infiltration and leakage, where Tony argues the models are still imperfect even with blower door data, and the real win is setting expectations: the HVAC design works under specific building conditions, and if the building does not match those conditions, performance issues are not automatically “bad calcs.” The conversation closes with a discussion of equipment selection, humidity, and where the industry is headed. Tony makes a clear point: most standard residential systems do not directly control humidity, and the code focuses on temperature performance, not a promised indoor RH target. They also touch on ACCA Manual S updates, oversizing rules for staged equipment, and Tony’s upcoming True Loads software, which uses the ASHRAE Heat Balance method to represent modern construction and time-lag effects better, while aiming to require fewer inputs than traditional Manual J workflows. TrueLoads website: Tony on LinkedIn: This episode was recorded in December 2025. /episode/index/show/buildinghvacscience/id/39628855

EP254 Mold, Moisture, and Missed Details: Lessons From the Building Science Trenches With Kohta Ueno (January 2026) 01/23/2026

EP254 Mold, Moisture, and Missed Details: Lessons From the Building Science Trenches With Kohta Ueno (January 2026) QUOTES from the episode: “Most building failures aren’t mysterious. They’re just ignored fundamentals.” “If you demand museum-level humidity, you’re no longer building a house. You’re building a museum.” “Moisture meters don’t solve problems. They show you patterns. The thinking solves the problem.” In this episode of the Building HVAC Science Podcast, Eric Kaiser is joined by Kohta Ueno, principal and co-owner of Building Science Corporation, for a wide-ranging discussion on building failures, moisture, HVAC, and the practical realities of diagnosing real-world problems. Kohta shares his unconventional path into building science, from small remodeling jobs and a PBS NOVA episode to decades of forensic investigations alongside Joe Lstiburek, one of the field’s most influential voices. The conversation quickly moves from origin stories into what really matters: how buildings fail, why those failures are often predictable, and how much cheaper it is to solve problems on paper than after construction. A major theme is moisture management, especially in high-performance and multifamily buildings. Kohta explains how seemingly small details, like window sill slope, back dams, airflow settings, and interior air seals, routinely separate durable buildings from expensive failures. He also highlights a growing perfect storm in modern construction: oversized HVAC equipment, high ventilation rates, poor commissioning, and limited dehumidification, particularly in smaller units. The result is mold, humidity complaints, and systems that technically run but fail to control moisture. The episode closes with a practical look at diagnostic tools and methods. Kohta emphasizes pattern recognition over single-point measurements, combining moisture meters, thermal imaging, pressure diagnostics, and blower door testing to understand how air, heat, and moisture actually move through buildings. He encourages listeners to use freely available Building Science Corporation research and Joe Lstiburek’s Building Science Insights as foundational resources, reminding the audience that most building failures are not mysterious. They are repeatable, understandable, and avoidable if the fundamentals are respected. Kohta’s LinkedIn: Links mentioned in the episode: Our Current HVAC Mess Experts discuss problems with residential HVAC systems as a first step toward defining solutions Proposed Solutions for Residential HVAC Problems Experts suggest ways to improve the quality of residential heating, ventilating, and cooling equipment installations A presentation on my investigations of multifamily humidity problems: Multifamily Humidity Control Problems: Muggy Mayhem I have done a presentation on the diagnostic tools I use in my buildings forensic work; here’s the slide deck: NESEA BE19 Tools of the Trade for Building Diagnostics March 14, 2019 And here’s a YouTube video: Tools of the Trade for Building Diagnostics with Kohta Ueno The complete rundown of Joe Lstiburek’s columns: And some of the research reports we did under Building America: This episode was recorded in January 2026. /episode/index/show/buildinghvacscience/id/39731830

EP253 The HVAC Trust Gap, and the Directory Built to Close It With Kevin R. Hart, Huff Hoffmaster & Darren Reuter (January 2026) 01/16/2026

EP253 The HVAC Trust Gap, and the Directory Built to Close It With Kevin R. Hart, Huff Hoffmaster & Darren Reuter (January 2026) Quotes from the episode: “Better isn’t a goal, it’s a direction.” “HVAC can feel like a house of mirrors for homeowners, and the cure is transparency plus measured results.” “We’re not trying to find the perfect contractor. We’re trying to find the contractor who keeps learning and won’t get complacent.” In this episode of the Building HVAC Science Podcast, Eric Kaiser flips the script and brings Bill Spohn on as a guest alongside Kevin Hart from Better HVAC and Darren Reuter and Huff Hoffmaster from Rewiring America. The group lays out a shared problem: homeowners face a significant information disadvantage when buying HVAC, often making a five-figure decision with no easy way to verify quality beyond marketing, promises, or price. That gap leads to mistrust, inconsistent outcomes, and too many “box swaps” that miss sizing, duct performance, commissioning, and homeowner education. Better HVAC exists to tip the odds back toward the homeowner by connecting people to contractors and individuals who commit to doing measured, commissioned work, and by aggregating trusted educational resources in one place. Rewiring America adds the consumer education and electrification planning layer, plus a push to scale adoption responsibly, with real contractor standards behind it. The partnership ties those strengths together: instead of building separate directories, they align on a shared pledge and a badging approach that helps homeowners and peers filter for contractors who are trained, insured, licensed, and willing to follow best practices, especially for heat pumps and whole-home electrification journeys that also include weatherization and energy auditing. Rewiring America’s website: BetterHVAC website: BetterHVAC Pledge: Huff’s LinkedIn : Kevin’s LinkedIn:Darren’s LinkedIn: Bill’s LinkedIn: Corbett’s list: This episode was recorded in January 2026 /episode/index/show/buildinghvacscience/id/39724425

EP252 The Perfection Trap in the Trades With Eric Kaiser (December 2025) 01/09/2026

EP251 Innovation in HVAC: The Quiet Shifts That Matter Most With Bill Spohn (December 2025) 01/02/2026

EP251 Innovation in HVAC: The Quiet Shifts That Matter Most With Bill Spohn (December 2025) Quotes from the Episode: “Innovation in HVAC isn’t one big breakthrough. It’s a series of quieter shifts that slowly change how we work.” “The future of HVAC depends on the people who measure, verify, and continuously improve.” “Collecting data is getting easier. Interpreting it well is where the real value lives.” “True innovation isn’t about chasing trends. It’s about reducing uncertainty and delivering better outcomes.” “Homes aren’t a collection of parts. They’re systems, and HVAC sits right in the middle of that system.” In this solo episode, Bill Spohn reflects on how innovation in HVAC really happens, not through one flashy breakthrough, but through a series of quieter, incremental shifts that compound over time. Drawing from 250 episodes of conversations on the Building HVAC Science podcast, Bill reframes innovation as a mindset grounded in measurement, feedback, and systems thinking rather than just new equipment. Bill walks through key patterns he has observed across the industry, including the shift from equipment-focused thinking to system-level performance, the rise of connected and cloud-based field tools, and the growing role of software in interpreting data rather than just collecting it. He highlights how smart tools, real-time diagnostics, commissioning workflows, and platforms like MeasureQuick have changed troubleshooting, accountability, and profitability for contractors who embrace them. The episode also explores major themes shaping the future of HVAC: electrification and heat pumps, dual-fuel strategies, improved load calculations and design software, smarter controls and commissioning, and the rapid evolution of indoor air quality from a niche topic to a core expectation. Bill emphasizes the increasing integration of HVAC with building science, ventilation, moisture, and enclosure performance, and points to contractors who are thriving by treating homes as complete systems. He closes by reinforcing that true innovation is about reducing uncertainty, improving outcomes, and supporting continuous learning, all while encouraging listeners to explore BetterHVAC as a growing nonprofit resource for contractors and homeowners alike. This episode was recorded in December 2025. /episode/index/show/buildinghvacscience/id/39554715

EP250 Beyond the Equipment: Reflections on 250 Episodes of HVAC and Building Science with Eric and Bill (December 2025) 12/26/2025

EP250 Beyond the Equipment: Reflections on 250 Episodes of HVAC and Building Science with Eric and Bill (December 2025) Quotes from the Episode: “Good building systems don’t start with equipment—they start with a plan and a thoughtful process.” “Most comfort problems aren’t equipment problems; they’re building problems we haven’t taken the time to understand.” “If even one episode helps someone take the next step in their career, then it’s all been worth it.” Episode 250 of the Building HVAC Science Podcast flips the script. Instead of Bill Spohn and Eric Kaiser doing the interviewing, TruTech Tools’ Senior Marketing Manager Ginny Hebert steps into the host seat to reflect on 250 episodes of conversations about comfort, buildings, and the people who work on them. What follows is an honest, thoughtful look back at what the show has uncovered—not just about HVAC systems, but about how people learn, think, and grow within the industry. Bill and Eric reflect on how their understanding of comfort has evolved, especially regarding concepts such as heat transfer, mean radiant temperature, air sealing, and treating the house as a system rather than a collection of parts. They discuss how many “equipment problems” are actually building or design problems, and why taking time to think—really think—about a problem is often the most valuable (and most overlooked) practice in the trade. The conversation highlights how technology, connected tools, and computing power have improved diagnostics, while also reinforcing that good outcomes still depend on mindset and process. The episode also looks forward. From normalizing system testing and indoor air quality assessments to improving how comfort is predicted and communicated, Bill and Eric share what they hope will become everyday practice over the next decade. Above all, this milestone episode is a thank-you to listeners, guests, and the broader HVAC and building science community—for staying curious, open-minded, and committed to doing better work for the people who live in the buildings we touch. Ginny’s LinkedIn: Eric’s LinkedIn: Bill’s LinkedIn: This episode was recorded in December 2025. /episode/index/show/buildinghvacscience/id/39455620

EP249 The Hidden Hazards: CO, H₂S and the Tech Behind Modern Gas Detection With Dave Massner from Sensorcon (December 2025) 12/19/2025

EP249 The Hidden Hazards: CO, H₂S and the Tech Behind Modern Gas Detection With Dave Massner from Sensorcon (December 2025) Episode quotes: “Hydrogen sulfide doesn’t announce itself. It can drift in, hit your mucus membranes, and start causing real harm before you know it’s there.” “You can’t treat sensor response like magic—it’s physics, chemistry, and smart filtering working together to tell you what’s actually happening in the space.” In this episode, Bill & Eric sit down with Dave Massner from Sensorcon, a long-time technical contributor in the world of portable gas detection, to dig into the realities behind CO, H₂S, and O₂ sensing in both HVAC and industrial environments. Bill recaps the origins of their relationship with Sensorcon, which sets the stage for Dave to explain why gas detection still matters and brings in real-world examples—from oil fields to everyday equipment rooms—to show how invisible hazards shape how techs should approach safety. The conversation explores lesser-understood threats like hydrogen sulfide (H₂S)—a gas that can travel with the wind in oil and gas regions and incapacitate workers before they realize it’s there. We discuss the physiology, the chemistry, and the grim speed at which exposure can become deadly. From there, we shift to oxygen depletion, clarifying what “too low” actually means in field work and why measuring O₂ is just as important as detecting toxic gases. The episode also gets into the nuts and bolts of sensor behavior: signal-to-noise ratios, filtering, raw output, response time, and the clever algorithms that help instruments stabilize faster without sacrificing accuracy. Toward the end, we highlight Sensorcon’s ongoing efforts in training, education, and transparency, pointing listeners to the company’s technical blog posts, videos, and calibration resources. We also make the case for low-level CO alarms and why TruTech Tools has championed them for over a decade. As we wrap up, we leave listeners with a simple takeaway: understand your sensors, understand your risks, and choose equipment that treats safety as something more than a checkbox. Dave’s LinkedIn: Sensorcon at TTT: Sensorcon blog posts: Sensorcon videos: Low-level CO alarms at TruTech Tools: This episode was recorded in December 2025. /episode/index/show/buildinghvacscience/id/39362350

EP248 Balanced Comfort, Brutal Lessons: Scaling, Losing Half Your Revenue, and Starting Over with AI with Aaron Husak (November 2025) 12/12/2025

EP248 Balanced Comfort, Brutal Lessons: Scaling, Losing Half Your Revenue, and Starting Over with AI with Aaron Husak (November 2025) “Inspect your marketing the way you’d inspect a home—run diagnostics, don’t guess.” – Aaron Husak “Attitude is way more important than aptitude. One bad apple really can infect the whole company.” – Aaron Husak In this episode of the Building HVAC Science podcast, Eric and Bill sit down with long-time friend and contractor-turned-marketing pro, Aaron Husak. Aaron traces his winding path from solar in the mid-2000s to building performance and BPI training, and then to founding Balanced Comfort in Fresno, CA. What started as a small HERS and energy-audit firm bootstrapped its way into insulation, HVAC, and weatherization, eventually landing on the Inc. 5000 list four times and scaling from $1.3M to over $12M in just a few years. Along the way, Aaron learned the complex realities of rapid growth: hiring quickly, depending on rebate programs, uncovering serious gaps in back-office accounting and HR, and navigating California’s legal landscape. Things got especially rough when PG&E abruptly pulled a weatherization program that made up half of their revenue, right as Aaron was also dealing with the personal loss of both his parents. A rescue buyer ultimately acquired the company in early 2025, giving Aaron a hard-earned exit. From that experience, Aaron pulls out lessons for contractors who want to grow without blowing themselves up. He emphasizes perseverance, but also warns that good field tech screening doesn’t automatically translate into good screening for accountants, HR, and support staff. He talks about the cost of keeping the wrong people too long, the importance of outside eyes on your books and compliance, and why attitude beats aptitude when building a healthy culture. He also calls out how easy it is to underestimate the impact of programs, receivables, and legal exposure—especially in states where “it doesn’t matter if you’re right, you still have to pay the attorney.” Today, Aaron has pivoted into his next chapter with Sequoia GEO, a marketing firm focused on contractors and local service businesses, with a special emphasis on AI and “GEO” (Generative Engine Optimization). He explains why your Google Business Profile is the low-hanging fruit almost everyone neglects, how AI tools and devices like Plaud can turn field conversations into high-value website content, and why AI “likes structure” (bullets, lists, and real stories). The episode closes with practical advice: inspect your marketing like you would inspect a home, use affordable diagnostic tools to see what’s really happening online, stay transparent with customers about recording and privacy, and treat expensive mistakes as lessons that tighten your processes for the future. Aaron’s LinkedIn: Aaron’s Company: Aaron’s Blog: This episode was recorded in November 2025. /episode/index/show/buildinghvacscience/id/39228525

EP247 From CEO to Chief Education Officer: Bill Spohn on Legacy, Leadership & Better HVAC (November 2025) 12/05/2025

EP247 From CEO to Chief Education Officer: Bill Spohn on Legacy, Leadership & Better HVAC (November 2025) “Get mad at the problem, not the person. When people feel safe, they’ll actually bring you the real issues.” - Bill Spohn “We’re woven into the fabric of this industry. The industry made me—so in a way, it owns me.” - Bill Spohn “What we have to learn to do, we learn by doing.” - Aristotle In this episode, Eric turns the mic around and interviews his co-host, Bill Spohn, about the evolution of TruTech Tools, his leadership philosophy, and why he’s shifting from “Chief Executive Officer” to “Chief Education Officer.” Bill traces the roots of TruTech back to late 2006, when a suggestion at a Testo Christmas party planted the seed for an online test-instrument business that launched in April 2007. He talks about how TruTech has become “woven into the fabric of the industry,” helping connect HVAC and building performance pros while focusing on specialty tools, education, and best practices. A big chunk of the conversation is about people: attracting and retaining the right employees, and running the business through the lens of core values. Bill and Eric walk through TruTech’s four core values—Do the Right Thing, Be a Team Player, Get It Done, and Be Attentive—and how they were distilled from nearly 80 traits the leadership team admired in their co-workers. Bill explains how these values show up in hiring (situational questions), in problem-solving (getting mad at the problem, not the person, and using the “five whys”), and in daily decisions about how to treat customers and each other. Bill also opens up about his intentional five-year transition plan out of day-to-day leadership and into a more advisory and educational role, including transferring ownership and the President role to his son. He shares why he didn’t want to be the owner who leaves on a stretcher—or the one who keeps wandering back in and undermining the next generation. Instead, he’s leaning into training the team, mentoring startups, and building out the Better HVAC directory as a free resource for contractors and consumers. Along the way, he and Eric talk about the “comfort industry” as a whole, the blending of HVAC and building performance, the importance of passing down institutional knowledge, and even Bill’s side quest to learn rock guitar and someday join the Building Science Boogie Band. This episode was recorded in November 2025. /episode/index/show/buildinghvacscience/id/39193505

EP246 Beyond MERV: The Truth About Smoke, Sensors, and Standards With Sissi Liu (October 2025) 11/28/2025

EP246 Beyond MERV: The Truth About Smoke, Sensors, and Standards With Sissi Liu (October 2025) Episode quotes: “Below about 0.4 microns, many low-cost PM sensors are basically guessing—right where wildfire smoke and aerosols live.” — Sissi Liu “Electrostatic filters can look great at first—and then fall off a cliff in smoke. Pressure drop won’t warn you.” — Sissi Liu “Science is a way of thinking much more than it is a body of knowledge.” — Carl Sagan Eric digs into the “fresh air” myth with Sissi Liu, CEO/co-founder of Metalmark Innovations and active ASHRAE committee member. Sissi explains why “outdoor = fresh” is context-dependent—urban pollution, agricultural activity, and especially wildfire smoke can make outdoor air worse than indoor air. Because air quality is dynamic, she pushes for comparing indoor and outdoor conditions in real time and ventilating intelligently, with attention to the energy cost of conditioning outside air. They then get nerdy on sensors and filters. Many low-cost PM2.5 laser-scattering sensors struggle below ~0.4 µm and can misread certain particle types (e.g., dark/black carbon), which matters because smoke and pathogen-carrying aerosols often live in the ~0.1–0.3 µm range. On filtration, Sissi contrasts mechanical vs. electrostatically charged media: electrostatic filters start efficiently with low pressure drop but can lose effectiveness within hours in smoke events. In contrast, mechanical media hold up better (though at higher pressure). She highlights ASHRAE 52.2 Appendix J (loaded efficiency) and argues that standards—along with reporting practices—must evolve for wildfire realities. Key takeaways “Fresh air” is conditional: check outdoor AQ (and indoor) before cranking up ventilation. IAQ is dynamic; test and compare locally rather than assuming static conditions. Consumer PM sensors can under-count the tiniest and darkest particles; treat data with caveats. Wildfire smoke clusters in the most-penetrating particle size (~0.1–0.3 µm) for many filters. Electrostatic filters may degrade fast in smoke; pressure drop alone won’t reveal failure. ASHRAE standards (e.g., 52.2 Appendix J, SGPC-44) are evolving—industry needs to catch up. Sissi’s LinkedIn: Metalmark website: This episode was recorded in October 2025. /episode/index/show/buildinghvacscience/id/39041295

EP245 Retrofit the Future: Inside PHIUS’s New Revive Standard with Al Mitchell and Haley Harlow (October 2025) 11/21/2025

EP245 Retrofit the Future: Inside PHIUS’s New Revive Standard with Al Mitchell and Haley Harlow (October 2025) Eric Kaiser sits down with Haley Harlow and Al Mitchell from PHIUS (Passive House Institute US) to explore Revive 2024, a groundbreaking new retrofit standard focused on thermal resilience and healthier, safer existing buildings. Haley shares her path from Pennsylvania College of Technology to her current role managing building certifications at PHIUS. At the same time, Al recounts his journey from aspiring car engineer to building scientist, drawn to the elegant complexity of whole-building systems. Together, they unpack how Revive differs from traditional PHIUS new-construction standards. Instead of focusing on heating and cooling load targets, Revive emphasizes thermal resilience—a building’s ability to remain habitable for up to a week during power outages or extreme weather. They also discuss ReviveCalc, PHIUS’s new software tool for analyzing retrofit scenarios, allowing designers to test various upgrade packages, balance cost and performance, and phase improvements over time. The tool incorporates lifecycle cost analysis, dynamic energy modeling, and resilience metrics, making advanced design decisions more accessible to real-world projects. Both guests share their excitement about addressing the massive stock of underperforming existing buildings. Haley connects it to her own experience growing up in energy-intensive apartments, while Al reflects on how to use today’s computing power better to design resilient, efficient homes. They close with a shared message: retrofitting our current buildings is not only possible, it’s essential for the future of sustainability, comfort, and community resilience. Key Takeaways PHIUS Revive 2024 focuses on retrofits, bringing resilience and energy equity to the existing building stock. Thermal resilience replaces traditional load metrics, ensuring buildings remain habitable during grid or system failures. ReviveCalc helps users model envelope and mechanical upgrades, estimate lifecycle costs, and optimize phase-by-phase improvements. The program aligns with ASHRAE Guideline 0.2 for commissioning and integrates EPA’s Energy Savings Plus Health framework. Air sealing remains the top “bang for the buck” retrofit measure for both comfort and energy savings. CPHC certification (Certified PHIUS Consultant) is open to anyone—no degree required. The Revive approach balances performance, cost, and practicality for real-world projects. Haley’s LinkedIn: Al’s LinkedIn: Info on Phius Revive 2024: This episode was recorded in October 2025. /episode/index/show/buildinghvacscience/id/39025265

EP244 Envelope, HVAC, and Humans: Solving the IAQ Puzzle with Brantley May (October 2025) 11/14/2025

EP244 Envelope, HVAC, and Humans: Solving the IAQ Puzzle with Brantley May (October 2025) Quotes by Brantley: “Most moisture problems are a three-way dance—envelope, mechanicals, and the occupants.” “Skim the light, don’t blast it. The right flashlight technique makes the invisible visible.” “If you only understand one piece of the system, you’re solving 1/3 of the problem.” Indoor environmental specialist Brantley May joins the show to unpack how he investigates moisture, mold, and air-quality problems through building forensics. Starting as a mold remediator in his family business, Brantley shifted to assessment work and now runs national investigations that pinpoint root causes—from envelope leaks and interstitial space connections to mechanical design and operation issues. He explains the value of “flashlight technique” (skimming light across surfaces to reveal early hyaline mold) and why good eyes, a light, and critical thinking are still the most important tools in the bag. Brantley walks through his toolkit—manometers, blower doors, pressure pans, thermal imagers, moisture meters, anemometers/flow hoods, data loggers, and even a backup sling psychrometer—plus his new favorite screening instrument, the InstaScope, which provides real-time readings on particulates, mold/pollen, bacteria/virus, VOCs, and CO₂. Investigations culminate in a report and protocols for the envelope, mechanicals, and remediation, often requiring tight coordination across multiple trades. He stresses pre-drywall inspections, “red-pen” continuous air/thermal barrier checks, and long-term monitoring to verify theories—especially on complex modern designs where vented attics and interstitial spaces end up unintentionally connected. A major theme: cross-disciplinary literacy. Most condensation/humidity problems stem from three interacting factors—envelope failure, mechanical failure, and occupant behavior—so HVAC pros must understand building science, and envelope pros must understand HVAC. Brantley shares how training (BPI, IICRC), mentorship, microscopy work (McCrone/Ochsner), and relentless curiosity shaped his practice. Watch for him at industry events (HVACR School Symposium, Build Show)—maybe even submitting a short BryX talk next time. Brantley’s LinkedIn: His company: His Instagram: McRone Institute: Instascope: Institute of Inspection Cleaning and Restoration Certification: Building Performance Institute: Building Science Summer Camp: National Home Performance Conference: This episode was recorded in October 2025. /episode/index/show/buildinghvacscience/id/38861145

EP243 Three Sensors, One Strategy: Making Maintenance Truly Smart With Kevin Weaver from SmartAC (October 2025) 11/07/2025

EP243 Three Sensors, One Strategy: Making Maintenance Truly Smart With Kevin Weaver from SmartAC (October 2025) Episode Quotes from Kevin Weaver: “If we can quantify delivered capacity on the air side, we can work our way back to what’s happening on the refrigerant side.” “We don’t have to diagnose everything remotely — we have to be great at saying, ‘there’s a problem,’ and prioritizing action.” “Even the best design can be wrecked at installation. Execution matters.” Chief Engineering Officer Kevin Weaver joins Eric and Bill to go beyond “remote monitoring” and explain how SmartAC is really a loyalty and trade-intelligence platform for residential HVAC. With three simple wireless sensors — a supply-air “comfort” sensor (temp/RH), a filter sensor (temp/static pressure), and a water sensor — plus a cloud-connected hub, SmartAC tracks delivered capacity and trends changes over time. That minimum viable data set lets contractors catch problems early, prioritize the right calls, and give homeowners peace of mind without needing full remote gauges. Kevin walks through the contractor toolset, which includes a white-labeled homeowner app, a Pro app for technicians, and a partner dashboard that also integrates with Field Service Management. (FSM) systems like ServiceTitan. The result is fewer emergency visits, healthier memberships, and durable customer relationships (i.e., less ad spend, more lifetime value). He previews Gen-2 hardware (more sensing in more places, stronger radios), battery options (18 months on AA lithiums or 5–8 years with a long-life pack), and notes that SmartAC is approaching 100k homes sold — building one of the most extensive residential HVAC data sets for richer insights across brands, geographies, and system types. We conclude with wisdom from Kevin’s Texas A&M research: even great designs can fail due to poor execution. Right-size returns, stretch flex, use collars and mastic, and keep static in check. SmartAC’s data helps expose oversizing, blower mis-settings, and undersized returns in days, transforming maintenance plans into smart maintenance and turning “transactional” customers into lifelong customers. Kevin’s LinkedIn: SmartAC: Earlier episode with founder Josh Teekell (Ep. 136): This episode was recorded in October 2025. /episode/index/show/buildinghvacscience/id/38755935

EP242 Give Every Heat Pump a Cell Phone - Predictive HVAC with Thalo Labs With Brendan Hermalyn (October 2025) 10/31/2025

EP242 Give Every Heat Pump a Cell Phone - Predictive HVAC with Thalo Labs With Brendan Hermalyn (October 2025) QUOTES from the Episode “Instead of landlines everywhere, give every heat pump a cell phone and let it call home.” “We’re seeing close to 40% of heat pumps undercharged or leaking—no wonder callbacks are high.” “What gets measured gets managed.” — often attributed to Peter Drucker (fitting this data-driven shift) Brendan Hermalyn (CEO/founder, Thalo Labs) traces a zig-zag path from NASA and defense to self-driving cars—then into HVAC. His through-line: high-reliability sensing and prognostics. Thalo’s product aims to “give every heat pump a cell phone,” using a small, non-invasive module that snaps inside VRFs/splits (and eventually larger plants), measures power and line temps, backhauls via cellular, and flags undercharge/leaks and power-quality issues before they become emergency calls. It’s equipment management, not a full BMS—lightweight to install, built for techs, and friendly to API integrations, texts, and weekly roll-ups. Brendan argues the market is ready: most commercial buildings still lack BMS, Wi-Fi is fragile for critical telemetry, and the economics of sensors/cloud have flipped. Thalo avoids tapping the refrigerant loop, prioritizes fast installs (often 10–30 minutes), QR/location tagging, and even a “buzz this unit” feature to find the right rooftop box. Early field data is sobering—he’s seeing ~40% of heat pumps undercharged and/or leaking—driving callbacks, compressor failures, and energy waste. The pitch to contractors: turn break-fix chaos into planned maintenance, white-label the savings report, and train new techs faster with data-driven cues. Oh, and the name? “Thalo” like the deep sky blue—an homage to adding tech to make the picture clearer. Brendan’s LinkedIn: Thalo Labs: This episode was recorded in October 2025. /episode/index/show/buildinghvacscience/id/38747020

EP241 Hydronics, Storage, and a Single Box: Berlin Raj’s Totex Vision (September 2025) 10/24/2025

EP241 Hydronics, Storage, and a Single Box: Berlin Raj’s Totex Vision (September 2025) Totex co-founder Berlin Raj joins Eric and “Overkill Bill” to unpack a single-box, hydronic monoblock system that combines space conditioning, domestic hot water, pool heating, thermal + lithium storage, EV charging integration, and backup power. Born from Berlin’s lifelong tinkering (and many shocks), the idea: stop wasting condenser heat—capture it for hot water while cooling. The system keeps all refrigerant sealed in the outdoor unit and runs PEX supply/return to indoor air handlers (ducted or ductless), avoiding field flares and refrigerant line runs. Install looks familiar—set the pad, pipe PEX, fill a glycol loop, wire power/control—yet it adds clever tricks: load matching from ~1.5–6 tons, dynamic load limiting for small panels (even ~20–30A circuits), modular thermal storage (~100 kWh cooling / ~55 kWh heating), a ~10.5 kWh lithium pack, and app/10" touchscreen controls over Modbus with hooks for BMS and home automation. In cooling-plus-hot-water mode, field tests show very high effective COP (Berlin cites “9+”) because the unit harvests both sides of the cycle. Engineered for residential and light commercial (think houses, small offices, QSRs), the unit can supply hot water up to ~165°F, support radiant/underfloor at lower temps, operate down to about -7.6°F, and be manifolded for capacity and redundancy. Texas is the target U.S. beachhead (long cooling seasons = months of “free” hot water), with pilots in Australia and U.S. pilots planned; broader availability is aimed for mid to late next year. Berlin’s closing note? “People, people, people”—comfort and outcomes start with humans. Notable Quotes: “Why dump condenser heat when you can use it? Cool the house and make hot water at the same time.” — Berlin Raj “Dynamic load balancing means a heat pump that plays nice with a 100-amp panel.” — Eric Kaiser (paraphrased) “People, people, people. Comfort is ultimately about humans first.” — Berlin Raj Berlin on LinkedIn: Totex website: Come visit with Berin in person at the This episode was recorded in September 2025. /episode/index/show/buildinghvacscience/id/38608020

EP240 Run Into the Fire: Curiosity, VRF, and the Rise of Roman Baugh (October 2025) 10/17/2025

EP239 Psychrometrics, Mobile Apps, and the Future of HVAC with Carmel Software (September 2025) 10/10/2025

EP238 From Talk to Proposal: NOSO’s Take on Ethical, Measured Sales With Winston Chi (September 2025) 10/03/2025

EP238 From Talk to Proposal: NOSO’s Take on Ethical, Measured Sales With Winston Chi (September 2025) “Use AI to augment people, not replace them.” “Windshield time is 30% of a tech’s day—let’s turn it into sales prep.” “Proposals should translate specs into homeowner value—comfort, savings, and choices.” In this episode, recorded live from the NCI Summit 2025 in Round Rock, TX, Bill and Eric sit down with Winston Chi, co-founder of NOSO Labs, to explore how AI can augment (not replace) HVAC technicians. Winston shares his path from a Google-backed, AI-driven startup in food wholesale to building tools for the trades, inspired by ride-alongs and family ties to hands-on work. His core thesis: most techs aren’t well trained in sales or structured communication, yet that’s precisely what turns field data into homeowner decisions. The goal is to streamline processes and eliminate friction, allowing techs to communicate clearly, follow up reliably, and close deals ethically. NOSO’s mobile-first app tackles three pain points: (1) windshield time becomes prep time via short audio job briefs (history, likely issues, “don’t forget the maintenance plan” cues); (2) on-site conversations (or quick self-notes) are recorded and auto-structured into clear summaries and proposals—with visuals instead of math walls—plus rebate and tax credit logic that stays current as programs change; and (3) follow-ups are auto-scheduled and teed up as texts or calls so opportunities don’t leak. A service manager dashboard displays follow-up activity, and there are native integrations (e.g., ServiceTitan and Housecall Pro). Winston also previews their massive manuals brain—~15 million HVAC/water-heater manuals searchable by photo/nameplate—so techs can look up specs fast. Early users span from San Diego to New Jersey; NOSO offers a short trial, then annual contracts. LINKS: Winston Chi: NoSo Labs: This episode was recorded in September 2025. /episode/index/show/buildinghvacscience/id/38331300

EP237 From Data to Decisions: Tools, Demos, and Takeaways from NCI With ELK and Bill (September 2025) 09/26/2025

EP237 From Data to Decisions: Tools, Demos, and Takeaways from NCI With ELK and Bill (September 2025) Some quotes: “When we treat the house as the biggest duct, comfort and performance finally line up.” “Field data becomes financial data the moment a homeowner decides—so it has to be right.” “If you can’t measure it, you can’t improve it.” — often attributed to Lord Kelvin Fresh back from the early-September NCI Summit in Austin, Bill and Eric recap three big themes: whole-home thinking, data you can trust, and tools that make better work faster. The “high-performance HVAC” mindset came through in a lively contractor panel moderated by Ben Lipscomb, where folks like Mitch Bailey, Dustin Cole, Ty Branaman, Jeremy Begley, MIcahel Cianfrocco, and others talked about uniting HVAC and building science to solve real problems, improve installs, and reduce callbacks. NCI’s training depth—airflow, combustion, diagnostics—was front and center, and the format (several sessions presented twice) helped attendees catch more of what mattered. Eric highlighted his session on using recorded field data for smarter troubleshooting and clearer homeowner communication, calling out platforms like MeasureQuick to aggregate, analyze, and report. On the show floor, you two dug into standout tools: the Shaeco fin-restoration attachment for oscillating tools (a genuine hail-damage time saver), the EEV-Mate for driving unipolar electronic expansion valves (with a demo Ty Branaman filmed), and Testo’s 860i wireless thermal imager that streams to a phone or tablet—great for homeowner show-and-tell. Startups NOSO Labs (AI for windshield-time prep and voice-note capture) and Thalo Labs (multi-point system sensors) hinted at where the trade is headed. With ~210 attendees and ~20 exhibitors—Fieldpiece, TEC, Daikin, Energy Circle, TSI, Sauermann, and more—the vibe was busy, practical, and optimistic. They also shouted out the Canadian contingent (including Anthony Woo, Contractor of the Year-Small) and noted EOS adoption gains. Bill also notes that BetterHVAC.org sign-ups ticked up to ~250 contractors, and he previewed a heavy fall travel calendar (Nexstar Super Meeting, Women in HVACR, BPA New England, Heat Pump Summit, ASHRAE Buildings XVI, etc.). NCI’s next Summit is slated for September 2026 the Great Smoky Mountains—contractors should keep an eye out. LINKS: Bill: Eric: NCI site: NCI Homeowner site: NCI Summit Site: The GRIT Foundation: The Joe Groh Foundation: Shaeco Coil Straightener: EEV Mate: Testo 860i: BetterHVAC: This episode was recorded in September 2025. /episode/index/show/buildinghvacscience/id/38281150

EP236 Details Matter, but So Does the Big Picture A Conversation with Lisa White of PHIUS (August 2025) 09/19/2025

EP236 Details Matter, but So Does the Big Picture A Conversation with Lisa White of PHIUS (August 2025) In this episode of the Building HVAC Science Podcast, Eric Kaiser and Bill Spohn welcome Lisa White, Associate Director of PHIUS, to explore the evolving world of passive building. Lisa shares her journey into building science, her role at PHIUS, and how the organization has grown from a niche movement into a force shaping multifamily and affordable housing projects across North America. She explains the core principles of passive building — thermal, air, and solar/radiation control — and how they translate into healthier, more comfortable, and more resilient spaces. Lisa also discusses PHIUS’s training and certification programs, the importance of third-party verification, and how tools like WUFI Passive and PHPP guide design decisions. The conversation touches on the challenges of balancing technical rigor with real-world implementation, the role of embodied carbon in standards development, and how passive building benefits not only owners and occupants, but also the broader environment. Lisa closes with reflections on persistence, growth, and optimism for the future of better buildings. “The details matter, but it’s the greater goal and intent behind them that truly counts.” — Lisa White “Passive building isn’t about eliminating systems; it’s about reducing the dependency on them.” — Lisa White Design Around People, A Good Building Follows” — Robert Bean (quoted by Eric Kaiser) Lisa shared a follow up thought after recording- her advice to younger self is "don't let perfect be the enemy of good -- while it's easy to get caught up in minor details, it's better to start by doing better and improve on that over time than to be held up by trying to be perfect at the onset.” As well as-- “never pass up an opportunity to educate yourself or to collaborate with others.” She has learned that the best things come out of collaborative and open-minded conversations. Lisa’s LinkedIn: PHIUS Website: The High Performance Staircase: This episode was recorded in August 2025. /episode/index/show/buildinghvacscience/id/37979365

EP235 Counter-Culture, Catharsis, and Craft: Nathan Orr on Kalos, Blue Rabbit, and Beyond (August 2025) 09/12/2025

EP234 Heat Transfer and Heart: What 40 Years in HVAC Can Teach Us All With Mike Uselof (July 2025) 09/05/2025

EP233 Thermal Cameras, AI, and Comfort: HomeBoost’s Big Idea with Selina Tobaccowala (July 2025) 08/29/2025

EP233 Thermal Cameras, AI, and Comfort: HomeBoost’s Big Idea with Selina Tobaccowala (July 2025) On this episode of the Building HVAC Science Podcast, Bill Spohn and Eric Kaiser are joined by seasoned tech entrepreneur Selina Tobaccowala, founder of HomeBoost.com, to discuss a new consumer-driven solution that brings energy comfort diagnostics into the modern era. Selina, whose background includes co-founding Evite and serving as President/CTO at SurveyMonkey, now applies her tech and behavioral insights to a space closer to home: energy efficiency and comfort. Selina shares the inspiration behind HomeBoost, a unique platform that empowers homeowners to scan and diagnose thermal and energy issues in their home using a FLIR thermal camera and guided app. The HomeBoost experience pairs smart tools, a mobile app, and AI plus human auditing to generate actionable home energy assessments — all while remaining accessible and affordable for the average homeowner. NEWSFLASH: HomeBoost Pro Launched on Oct 8, 2025! Learn more at this link: The conversation dives into product design, user testing, partnerships with utilities and contractors, and the launch of a pro version that streamlines report generation for BPI-certified energy assessors. The team also explores broader themes, including the cultural value of skilled trades and how education models from Europe could inspire new respect and opportunity for trade careers in the U.S. The episode closes with a hopeful vision of HomeBoost expanding nationally and scaling its impact — one home, one assessment, and one contractor at a time. “It’s not about selling energy — it’s about helping people use less of it.” – Selina Tobaccowalla “We had scientific accuracy, but we hadn’t built a product consumers liked — that took iteration.” – Selina “AI won’t replace a tradesperson. That’s why we need to value skilled trades more — like they do in Germany.” – Selina HomeBoost: Selina’s LinkedIn: This episode was recorded in July 2025. /episode/index/show/buildinghvacscience/id/37595460

EP232 Dry Air Done Right: The Art and Science of Dehumidification With Nikki Krueger (July 2025) 08/22/2025

EP231 Reimagining HVAC Sales: How Eden Is Modernizing the Home Upgrade Journey with Josh Koplin (July 2025) 08/15/2025

EP230 Beyond Smoke and CO: The Case for Natural Gas Alarms with Marc A. Adams (July 2025) 08/08/2025

Building HVAC Science

TOPICS