#sensible heat ratio

Tech Tips:

Coil SHR, Ventilation, and Bypass Factor – Advanced Psychrometrics Part 2

This is the second article in a three-part series where we explore advanced psychrometrics. The source material for each of the articles in this series is ACCA Manual P Sections 3, 4, and 5. This article is based on information found in Section 4. If you followed the previous advanced psychrometrics article, you now know […]

Q&A – System Won’t Dehumidify? – Short #214

In this short podcast episode, Bryan answers a listener-submitted question about an HVAC system that won't dehumidify. This question was submitted by a homeowner with a Carrier heat pump with an attic air handler that cools but won't dehumidify on the hottest days of summer. One of the past companies that serviced the system […]

Check out our most recent video

How to Evacuate an AC system, Full Vacuum Procedure

Our latest Podcast

HVAC School – For Techs, By Techs

Real training for HVAC ( Heating, Ventilation, Air Conditioning and Refrigeration) Technicians. Including recorded tech training, interviews, diagnostics and general conversations about the trade.

In this episode of the HVAC School podcast, host Bryan sits down with building science expert Allison Bailes to dive deep into the world of Energy Recovery Ventilators (ERVs). The conversation explores the critical role of ventilation in modern homes, highlighting how ERVs have become an essential component of maintaining indoor air quality and energy efficiency. Bailes breaks down the technical nuances of ERVs, explaining how these systems not only bring fresh air into a home but do so while recovering both temperature and moisture energy.

The discussion goes beyond simply explaining what an ERV is, delving into the practical considerations of ventilation strategies. Bailes shares personal experiences, including challenges he faced with over-ventilation in his own home, which led to extremely dry indoor conditions. The podcast explores the complex balance of bringing outdoor air inside while managing humidity, temperature, and air quality. Listeners gain insights into why simply bringing in outdoor air isn’t always the best solution, especially in climates with extreme humidity or air quality challenges.

Throughout the episode, Bailes and Bryan emphasize the importance of thoughtful ventilation design. They discuss the evolution of home construction, noting how increasingly airtight buildings have made proper ventilation more crucial than ever. The conversation touches on key considerations for selecting and implementing ERVs, including motor efficiency, boost capabilities, filtration, and the impact of outdoor air conditions. The experts provide practical advice for contractors, technicians, and homeowners looking to improve their understanding of indoor air management.

Key Topics Covered:

The difference between Energy Recovery Ventilators (ERVs) and Heat Recovery Ventilators (HRVs)
Moisture transfer and vapor permeability in ventilation systems
Balanced ventilation strategies and their importance
Challenges of over-ventilation and indoor air quality
Filtration considerations for ERV systems
Impacts of outdoor air quality on home ventilation
Strategies for different climate zones
The role of ERVs in managing indoor humidity and temperature

Resources Mentioned: