Uploaded June 2026 | Updated September 2026, 2 weeks ago
How much outdoor air does your home actually need — and what's the right strategy to bring it in without wrecking comfort or humidity control? In this HVAC School livestream, Bryan Orr sits down with John Semmelhack, Ty Branaman, and Tim DeStasio for a deep dive into residential ventilation strategies that actually work in the field.
The crew covers the three core approaches to managing indoor air — circulation, extraction, and dilution with outdoor air — and breaks down when each one makes sense. You'll hear real talk on ERV vs. exhaust-only systems, why "outdoor air" isn't always "fresh air," and how climate (humid vs. dry) completely changes your ventilation design decisions.
Topics covered in this episode include:
Why ventilation (the "V" in HVAC) is the most overlooked part of the system
ASHRAE 62.2 ventilation requirements and common misunderstandings
Blower door testing and air infiltration rates in tight, high-performance homes
Moisture and humidity control when introducing outdoor air
ERV/HRV systems, exhaust-only ventilation, and balanced ventilation strategies
Dehumidifiers and how they pair with mechanical ventilation
Range hoods and combustion safety considerations
Crawl space and duct design impacts on indoor air quality
Filtration, MERV ratings, and pollutant control
Real-world retrofit vs. new construction ventilation approaches
Whether you're designing new builds, retrofitting older homes, or just trying to wrap your head around outdoor air strategies, this conversation with John Semmelhack, Ty Branaman, Tim DeStasio, and Bryan Orr is packed with practical, real-world insight you can apply on your next call.
How much outdoor air does your home actually need — and what's the right strategy to bring it in without wrecking comfort or humidity control? In this HVAC School livestream, Bryan Orr sits down with John Semmelhack, Ty Branaman, and Tim DeStasio for a deep dive into residential ventilation strategies that actually work in the field.
The crew covers the three core approaches to managing indoor air — circulation, extraction, and dilution with outdoor air — and breaks down when each one makes sense. You'll hear real talk on ERV vs. exhaust-only systems, why "outdoor air" isn't always "fresh air," and how climate (humid vs. dry) completely changes your ventilation design decisions.
Topics covered in this episode include:
Why ventilation (the "V" in HVAC) is the most overlooked part of the system
ASHRAE 62.2 ventilation requirements and common misunderstandings
Blower door testing and air infiltration rates in tight, high-performance homes
Moisture and humidity control when introducing outdoor air
ERV/HRV systems, exhaust-only ventilation, and balanced ventilation strategies
Dehumidifiers and how they pair with mechanical ventilation
Range hoods and combustion safety considerations
Crawl space and duct design impacts on indoor air quality
Filtration, MERV ratings, and pollutant control
Real-world retrofit vs. new construction ventilation approaches
Whether you're designing new builds, retrofitting older homes, or just trying to wrap your head around outdoor air strategies, this conversation with John Semmelhack, Ty Branaman, Tim DeStasio, and Bryan Orr is packed with practical, real-world insight you can apply on your next call.
