EP241 Hydronics, Storage, and a Single Box: Berlin Raj’s Totex Vision (September 2025)
Release Date: 10/24/2025
EP252 The Perfection Trap in the Trades With Eric Kaiser (December 2025)
Building HVAC Science
Quotes from the episode: “Good enough isn’t a fixed point. It’s a moving target shaped by goals, expectations, and consequences.” “Perfection can push us forward, but it can also quietly pull us off track.” “If I delivered what I promised, in the time promised, using the resources promised, that is good enough for me.” “The real skill is knowing when extra effort adds value and when it just adds ego.” In this solo monologue episode, Eric Kaiser explores a deceptively simple question: Can good enough be perfect? Drawing on years of experience in the trades, Eric...
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EP251 Innovation in HVAC: The Quiet Shifts That Matter Most With Bill Spohn (December 2025)
Building HVAC Science
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,...
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EP250 Beyond the Equipment: Reflections on 250 Episodes of HVAC and Building Science with Eric and Bill (December 2025)
Building HVAC Science
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...
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EP249 The Hidden Hazards: CO, H₂S and the Tech Behind Modern Gas Detection With Dave Massner from Sensorcon (December 2025)
Building HVAC Science
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...
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EP248 Balanced Comfort, Brutal Lessons: Scaling, Losing Half Your Revenue, and Starting Over with AI with Aaron Husak (November 2025)
Building HVAC Science
“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...
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EP247 From CEO to Chief Education Officer: Bill Spohn on Legacy, Leadership & Better HVAC (November 2025)
Building HVAC Science
“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...
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EP246 Beyond MERV: The Truth About Smoke, Sensors, and Standards With Sissi Liu (October 2025)
Building HVAC Science
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...
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EP245 Retrofit the Future: Inside PHIUS’s New Revive Standard with Al Mitchell and Haley Harlow (October 2025)
Building HVAC Science
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....
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EP244 Envelope, HVAC, and Humans: Solving the IAQ Puzzle with Brantley May (October 2025)
Building HVAC Science
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...
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EP243 Three Sensors, One Strategy: Making Maintenance Truly Smart With Kevin Weaver from SmartAC (October 2025)
Building HVAC Science
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...
info_outlineTotex 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:https://www.linkedin.com/in/berlinrajm/
Totex website: https://www.totexenergy.com/
Come visit with Berin in person at the www.USHeatPumpSummit.com
This episode was recorded in September 2025.