Everyone blames the HVAC System. Most of the time, that’s wrong. Nikki Krueger breaks down why modern homes struggle with humidity, even with high-efficiency systems, and why dehumidification has become a missing piece in comfort, health, and durability.

Sam, Ben and Nikki talk crawl spaces, shoulder seasons, overcooling, air leakage, ventilation mistakes, and the real-world install details contractors keep getting wrong.

If you work on houses, or live in one ... this conversation will change how you think about moisture control.

Video Notes:
Placement and Ducting of Dehumidifiers (2:31)
Air Distribution and Heat Generation (6:08)
Retrofitting and Challenges in Existing Homes (8:51)
Humidity Control and Building Codes (12:20)
Ventilation Strategies and Industry Advancements (29:07)
Contractor Mistakes and Best Practices (38:56)
Industry Collaboration and Future Directions (48:11)
Final Thoughts and Future Opportunities (49:52)

Connect with :
Nikki Kruger
Website: www.-Santa-Fe-Products.com
LinkedIn: https://www.linkedin.com/in/nikkikrueger/
Instagram: https://www.instagram.com/nikkikrueger_iaq/
Facebook: https://www.facebook.com/nikki.krueger.71

Follow Hosts:
Ben Walker (Co-CEO, Retrotec)
LinkedIn: https://www.linkedin.com/in/ben-walker-4a05901/

Sam Myers (Building Science Specialist & Trainer)
LinkedIn: https://www.linkedin.com/in/sam-myers-ms-a9a4a546/

Website: https://retrotec.com/
Facebook: https://www.facebook.com/retrotec/
Instagram: https://www.instagram.com/retrotec/
YouTube: https://www.youtube.com/@RetrotecEnergy/

Listen on
Spotify: https://open.spotify.com/show/3xMDAhIttUTHWK41DH7KhB

Don’t forget to subscribe for more episodes on airtightness, ventilation strategies, and innovations in building science!

#BuildingScience #AirtightnessTesting #EnergyEfficiency #BuildingPerformance #HVAC #Retrotec #GreenStar #EnergyWaste #HomeImprovement

High school students are building real, high-performance homes… and hitting 0.9 ACH50. Matt Blomquist joins The Flow Lab to unpack how his class builds tighter houses than most pros, why blower-door testing is a game-changer, and how hands-on education is shaping the next generation of builders.

If you care about building science, air sealing, or the future of the trades, this episode hits hard.

Matt Blomquist's Journey into Teaching and House Building (0:00)
Starting the House Building Program (3:16)
Student Involvement and Class Structure (4:31)
Challenges and Achievements in House Building (42:20)
High Performance Building Science (42:38)
Impact and Future of the Program (42:54)

Video Notes:
Matt Blomquist's Journey into Teaching and House Building (0:00)
Starting the House Building Program (3:16)
Student Involvement and Class Structure (4:31)
Challenges and Achievements in House Building (42:20)
High Performance Building Science (42:38)
Impact and Future of the Program (42:54)

Connect with :
Matt Blomquist
Instagram: https://www.instagram.com/build_learn_teach/
TikTok: https://www.tiktok.com/@build_learn_teach
LinkedIn: https://www.linkedin.com/in/mattblomquist/

Follow Hosts:
Ben Walker (Co-CEO, Retrotec)
LinkedIn: https://www.linkedin.com/in/ben-walker-4a05901/

Sam Myers (Building Science Specialist & Trainer)
LinkedIn: https://www.linkedin.com/in/sam-myers-ms-a9a4a546/

Website: https://retrotec.com/
Facebook: https://www.facebook.com/retrotec/
Instagram: https://www.instagram.com/retrotec/
YouTube: https://www.youtube.com/@RetrotecEnergy/

Listen on
Spotify: https://open.spotify.com/show/3xMDAhIttUTHWK41DH7KhB

Don’t forget to subscribe for more episodes on airtightness, ventilation strategies, and innovations in building science!

#BuildingScience #AirtightnessTesting #EnergyEfficiency #BuildingPerformance #HVAC #Retrotec #GreenStar #EnergyWaste #HomeImprovement

On this episode of Flow Lab, Ben Walker and Sam Myers sit down with Leilani Orr and Ty Branaman from the Grit Foundation to talk about a very practical way to grow the trades pipeline: youth camps where kids actually do the work.

Instead of PowerPoints and lectures, these camps drop 12–17-year-olds into escape-room-style challenges with real tools, real wiring, and real jobsite scenarios. Mentors don’t just “show and tell," they use a Socratic, question-first approach so kids learn to think, measure, troubleshoot, and fix things for themselves.

You’ll hear how the camps are structured, what it realistically takes to host one, and why mentors come away just as energized as the students. From high-school interns in Retrotec’s engineering department to kids proudly taking home their own wired “wall boxes,” this episode is a how-to guide for turning “we need more people in the trades” into real action in your own community.

In this episode, we get into:
- How the Grit Foundation youth camps introduce 12–17-year-olds to the trades using real tools, real circuits, and jobsite-style scenarios
- Why curiosity, questions, and mistakes are built into their Socratic teaching approach
- The mentor’s role, the 1:2 mentor-to-student ratio, and how a detailed playbook keeps camp days on track
- What it actually takes to host a camp: facilities, background checks, safety, and community partners
- How these camps help kids connect the dots between fix-it life skills and real career paths
- Why building science and HVAC are directly tied to public health and safety, not just comfort
- How programs like this can help your local market build its own long-term talent pipeline

If you’ve ever said, “We need more people who actually understand how buildings work,” this episode shows one concrete way to start building that future, right where you live.

Video Notes:
00:00 – Welcome to Flow Lab & Why the Trades Shortage Matters
01:21 – Meet Grit Foundation & How the Youth Camps Started
04:50 – Escape-Room Style Camps That Make the Trades Fun
09:15 – Willis Carrier, Curiosity & the Socratic Teaching Model
13:28 – Training Mentors & Walking Through a Camp Day
17:36 – Real Impact on Students, Mentors & Retrotec Interns
27:47 – What It Takes to Host a Grit Foundation Camp
39:32 – Defining Success & Building Local Talent Pipelines
45:00 – Bringing Curiosity Home & Connecting Trades to Health

Connect with :
The Grit Foundation Website: www.thegritfoundation.com
Grit Foundation Facebook: https://www.facebook.com/profile.php?id=61572576687441
Grit Foundation Instagram: https://www.instagram.com/gritfoundation25
Grit Foundation LinkedIn: https://www.linkedin.com/company/the-grit-foundation/?viewAsMember=true

Follow Hosts:
Ben Walker (Co-CEO, Retrotec)
LinkedIn: https://www.linkedin.com/in/ben-walker-4a05901/

Sam Myers (Building Science Specialist & Trainer)
LinkedIn: https://www.linkedin.com/in/sam-myers-ms-a9a4a546/

Website: https://retrotec.com/
Facebook: https://www.facebook.com/retrotec/
Instagram: https://www.instagram.com/retrotec/
YouTube: https://www.youtube.com/@RetrotecEnergy/

Listen on
Spotify: https://open.spotify.com/show/3xMDAhIttUTHWK41DH7KhB

Don’t forget to subscribe for more episodes on airtightness, ventilation strategies, and innovations in building science!

#BuildingScience #AirtightnessTesting #EnergyEfficiency #BuildingPerformance #HVAC #Retrotec #GreenStar #EnergyWaste #HomeImprovement

Solar & heat pumps can be a dream team or a challenge when time‑of‑use rates and sloppy sizing collide. Brent Davidson joins Ben Walker and Sam Myers to share a contractor‑first playbook: fix the enclosure, model the real load, then pair PV, storage, and controls so bills go down and stay down. We discuss home battery technology, how TOU windows change design decisions, and why rules of thumb (500‑sq‑ft‑per‑ton) still wreck outcomes. Brent also previews the US Heat Pump Summit happening in November 2025. This event is built to connect technical training with business systems so good work actually scales.

Show Notes:

00:00 When solar + heat pumps backfire

00:42 Welcome + guest intro: Brent Davidson

00:56 US Heat Pump Summit in Worcester

02:06 From utility-scale solar to home performance tools

17:12 Home batteries are coming fast

19:15 Time-of-use rates and the real load profile

21:04 Order of operations and cross-trade coordination

33:41 Sizing reality and Manual J pitfalls (with better tools)

40:21 Inverters, downtime, and designing for resilience

Connect with Brent Davidson:

Personal LI Profile: https://www.linkedin.com/in/brentdavidson/

Company LI Page: https://www.linkedin.com/company/us-heat-pump-summit/

Website: https://www.usheatpumpsummit.com/

Facebook: https://www.facebook.com/profile.php?id=61577100464455

Instagram: https://www.instagram.com/usheatpumpsummit/

Follow Hosts:

Ben Walker (Co-CEO, Retrotec)

LinkedIn: https://www.linkedin.com/in/ben-walker-4a05901/

Sam Myers (Building Science Specialist & Trainer)

LinkedIn: https://www.linkedin.com/in/sam-myers-ms-a9a4a546/

Website: https://retrotec.com/

Facebook: https://www.facebook.com/retrotec/

Instagram: https://www.instagram.com/retrotec/

YouTube: https://www.youtube.com/@RetrotecEnergy/

Listen on:

Spotify: https://open.spotify.com/show/3xMDAhIttUTHWK41DH7KhB

Don’t forget to subscribe for more episodes on airtightness, ventilation strategies, and innovations in building science!

#BuildingScience #AirtightnessTesting #EnergyEfficiency #BuildingPerformance #HVAC #Retrotec #GreenStar #EnergyWaste #HomeImprovement

Follow Hosts:
Ben Walker (Co-CEO, Retrotec)
LinkedIn: https://www.linkedin.com/in/ben-walker-4a05901/

Sam Myers (Building Science Specialist & Trainer)
LinkedIn: https://www.linkedin.com/in/sam-myers-ms-a9a4a546/

Website: https://retrotec.com/
Facebook: https://www.facebook.com/retrotec/
Instagram: https://www.instagram.com/retrotec/
YouTube: https://www.youtube.com/@RetrotecEnergy/

Listen on
Spotify: https://open.spotify.com/show/3xMDAhIttUTHWK41DH7KhB

Don’t forget to subscribe for more episodes on airtightness, ventilation strategies, and innovations in building science!

#BuildingScience #AirtightnessTesting #EnergyEfficiency #BuildingPerformance #HVAC #Retrotec #GreenStar #EnergyWaste #HomeImprovement

The basics to help you understand homes as a system. Download our FREE ebook and start solving problems like a pro. 👉 https://bit.ly/flow-lab-ebook

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In this episode of The Flow Lab Podcast, hosts Ben Walker and Sam Myers are joined by John Konstantakopoulos and Joseph Cheung to discuss the challenges of improving airtightness and energy efficiency in Australian homes. The conversation explores the nuances of building construction in Australia, where airtightness and ventilation systems are not always prioritized, leading to major inefficiencies.

John and Joseph share their insights on how to solve common issues in Australian building practices, especially regarding the impact of air leaks on energy waste, comfort, and health. They explain the importance of a whole-building approach to airtightness and ventilation, and how residential buildings could benefit from more awareness and implementation of airtightness testing.

What You’ll Learn

• The impact of air leaks on building performance and energy efficiency
• The role of ventilation in maintaining a healthy indoor environment
• How Australian homes compare to US and UK homes in terms of airtightness
• The challenges faced by Australian builders and how to address them
• Why continuous ventilation is key for airtight buildings
• Strategies for improving airtightness and reducing energy waste in various climates

Episode Breakdown with Timestamps

[00:00] - Introduction

[05:50] - How did Efficiency Matrix start

[08:38] - Green Building Council, Australia

[14:48] - Common causes of leakage rates and how to solve them

[16:27] - New Products on Efficiency Matrix

[19:06] - Efficiency Matrix isn’t just for testing

[25:43] - Design considerations for the open area and vent

[28:43] - Envelope Integrity Report

[33:43] - Logging issues after blower test

[36:44] - Closing thoughts: EIR website and Subscription

Connect with John K

• LinkedIn: https://www.linkedin.com/in/johnkonstan/?originalSubdomain=au
• Company Website: ht

Follow Hosts:
Ben Walker (Co-CEO, Retrotec)
LinkedIn: https://www.linkedin.com/in/ben-walker-4a05901/

Sam Myers (Building Science Specialist & Trainer)
LinkedIn: https://www.linkedin.com/in/sam-myers-ms-a9a4a546/

Website: https://retrotec.com/
Facebook: https://www.facebook.com/retrotec/
Instagram: https://www.instagram.com/retrotec/
YouTube: https://www.youtube.com/@RetrotecEnergy/

Listen on
Spotify: https://open.spotify.com/show/3xMDAhIttUTHWK41DH7KhB

Don’t forget to subscribe for more episodes on airtightness, ventilation strategies, and innovations in building science!

#BuildingScience #AirtightnessTesting #EnergyEfficiency #BuildingPerformance #HVAC #Retrotec #GreenStar #EnergyWaste #HomeImprovement

The basics to help you understand homes as a system. Download our FREE ebook and start solving problems like a pro. 👉 https://bit.ly/flow-lab-ebook

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In this episode of The Flow Lab Podcast, hosts Ben Walker and Sam Myers sit down with Sean Maxwell, Scheme Manager at ATTMA Australia & New Zealand, to discuss airtightness in buildings and the challenges of improving energy efficiency. From working with builders on airtightness practices to improve building codes, Sean shares his insights into the evolution of building science and the potential for large-scale improvements in comfort and energy use.

Sean walks us through his journey in building science, including his time with the Energy Star Homes program and his efforts in advancing airtightness testing in Australia. He highlights the importance of both individual apartment and whole-building tests, discusses the role of ventilation systems in airtight buildings, and shares his thoughts on the future of energy efficiency standards.

What You’ll Learn:

• How testing individual apartments can improve indoor air quality and reduce stack effect.
• The importance of airtightness testing in reducing energy waste and improving comfort.
• Strategies for improving building performance in various climates.
• Why continuous ventilation is crucial for modern buildings, and how to implement it effectively.
• Challenges with building codes in different regions and how they impact testing and energy savings.

In This Episode:

[00:00] - Introduction to Sean Maxwell and the importance of blower door testing

[01:42] - Sean's background in building science and his journey from New York to Australia

[03:33] - Discussing the challenges of airtightness in buildings and why it’s often overlooked

[05:48] - Common issues causing air leaks: windows, doors, and poor construction practices

[10:20] - How airtightness impacts building comfort and energy efficiency

[13:07] - The importance of ventilation in airtight buildings and strategies for effective implementation

[18:43] - Ventilation strategies: Exhaust fans, ERVs, and occupant-controlled systems

[19:59] - Building code issues and differences in airtightness regulations across regions

[27:19] - The need for collaboration in building science: Sharing knowledge a

Follow Hosts:
Ben Walker (Co-CEO, Retrotec)
LinkedIn: https://www.linkedin.com/in/ben-walker-4a05901/

Sam Myers (Building Science Specialist & Trainer)
LinkedIn: https://www.linkedin.com/in/sam-myers-ms-a9a4a546/

Website: https://retrotec.com/
Facebook: https://www.facebook.com/retrotec/
Instagram: https://www.instagram.com/retrotec/
YouTube: https://www.youtube.com/@RetrotecEnergy/

Listen on
Spotify: https://open.spotify.com/show/3xMDAhIttUTHWK41DH7KhB

Don’t forget to subscribe for more episodes on airtightness, ventilation strategies, and innovations in building science!

#BuildingScience #AirtightnessTesting #EnergyEfficiency #BuildingPerformance #HVAC #Retrotec #GreenStar #EnergyWaste #HomeImprovement

The basics to help you understand homes as a system. Download our FREE ebook and start solving problems like a pro. 👉 https://bit.ly/flow-lab-ebook

--------------------------------

In this episode of The Flow Lab Podcast, hosts Ben Walker and Sam Myers sit down with Denali Jones, Technical Director at the Air Barrier Association of America (ABAA), to talk about how large buildings are tested for air tightness and where things often go wrong.Denali walks us through his journey from starting out at Retrotec to leading airtightness training across the country. He explains what makes these tests challenging, how contractors can avoid common mistakes, and why having the right training and tools really matters.

Whether you work in building science, test commercial properties, or just want to understand how building air leaks affect energy use and comfort, this episode breaks it all down from spotting hidden gaps to troubleshooting test-day problems like faulty fans or even elevator issues.

• Why some parts of new and old buildings are often forgotten and how that affects test results.
• How Denali helped create the first nationally recognized training for testing large buildings.
• What to check when test results don’t make sense like unplugged equipment or bad setup.
• How testing two floors at a time helps deal with tall buildings and air pressure issues.
• What makes this new standard better than the old ones and how it helps testers and builders do the job right.

[00:00] - Denali’s background and how he got started

[04:50] - First testing jobs and early lessons

[08:00] - Where buildings leak and why

[13:08] - Testing tall buildings and working with city codes

[19:28] - How the ABAA training program came together

[26:49] - The most common mistakes testers make

[33:52] - What’s next for airtightness testing

[37:37] - Why it’s better to bring in testers early

[44:44] - Tips for using fans and setting up safely

[50:12] - Real-world testing results and future research plans

Connect with Denali Jones:

LinkedIn: https://www.linkedin.com/in/denali-jones-4b6b8375/

Connect with Company:

Website:

Follow Hosts:
Ben Walker (Co-CEO, Retrotec)
LinkedIn: https://www.linkedin.com/in/ben-walker-4a05901/

Sam Myers (Building Science Specialist & Trainer)
LinkedIn: https://www.linkedin.com/in/sam-myers-ms-a9a4a546/

Website: https://retrotec.com/
Facebook: https://www.facebook.com/retrotec/
Instagram: https://www.instagram.com/retrotec/
YouTube: https://www.youtube.com/@RetrotecEnergy/

Listen on
Spotify: https://open.spotify.com/show/3xMDAhIttUTHWK41DH7KhB

Don’t forget to subscribe for more episodes on airtightness, ventilation strategies, and innovations in building science!

#BuildingScience #AirtightnessTesting #EnergyEfficiency #BuildingPerformance #HVAC #Retrotec #GreenStar #EnergyWaste #HomeImprovement

The basics to help you understand homes as a system. Download our FREE ebook and start solving problems like a pro. 👉 https://bit.ly/flow-lab-ebook

--------------------------------

In this episode of The Flow Lab Podcast, hosts Ben Walker and Sam Myers are joined by Barry Cope, Managing Director of ATTMA (Air Tightness Testing and Measurement Association), affectionately known as "Mr. Blower Door" in the UK. Barry discusses how ATTMA grew from a small group of enthusiasts into a global leader in blower door testing, certification, and industry training.

He shares groundbreaking insights into data-driven building performance, the UK’s fully integrated Lodgement system, and ATTMA’s cutting-edge training house built inside a warehouse. With humor and unmatched expertise, Barry highlights the challenges of international code compliance, quality assurance, and the vision for bringing proven UK methodologies to North America.

• Discover how a four-person trade association grew to dominate 85% of the UK’s blower door testing market with over 180,000 tests annually.
• Get inspired by ATTMA’s full-scale training house inside a 10,000 sq ft warehouse, designed for high-pressure, real-world simulations.
• Explore the chaos of U.S. state-by-state code amendments versus the streamlined approach in the UK and how that affects adoption and testing quality.
• Learn how ATTMA’s Lodgement system helps governments track high-rise buildings, manage compliance, and even respond to national emergencies like Grenfell.
• Hear Barry’s journey from field tester to managing director, and how his multidisciplinary background shaped the future of UK air tightness testing.

In Today’s Episode

[00:00] - How ATTMA Helped Identify High-Rise Risks After Grenfell

[01:13] - Introduction and Barry’s Role in the UK Blower Door Market

[02:07] - What is ATTMA and How It Evolved

[04:36] - Barry’s Entry into the Industry and ATTMA’s Transformation

[06:25] - Building a Full-Scale Training House Inside a Warehouse

[09:22] - Real-World Pressure Testing and Training Innovation

[11:17] - Bringing the Lodgment System to the U.S.

[16:00] - The Challenges of Code Fragmentation in the U.S.

[21:37] - ABA’s Expansion and ISO Certification Progress

[28:05] - Who Has Access to UK Building Test Data

[34:18] - Air Tightness Metrics: Volume vs. Sur

Follow Hosts:
Ben Walker (Co-CEO, Retrotec)
LinkedIn: https://www.linkedin.com/in/ben-walker-4a05901/

Sam Myers (Building Science Specialist & Trainer)
LinkedIn: https://www.linkedin.com/in/sam-myers-ms-a9a4a546/

Website: https://retrotec.com/
Facebook: https://www.facebook.com/retrotec/
Instagram: https://www.instagram.com/retrotec/
YouTube: https://www.youtube.com/@RetrotecEnergy/

Listen on
Spotify: https://open.spotify.com/show/3xMDAhIttUTHWK41DH7KhB

Don’t forget to subscribe for more episodes on airtightness, ventilation strategies, and innovations in building science!

#BuildingScience #AirtightnessTesting #EnergyEfficiency #BuildingPerformance #HVAC #Retrotec #GreenStar #EnergyWaste #HomeImprovement