How One-Inch MERV 11 Filters Can Work With the Right HVAC Airflow Design - Part 2

In this episode of HVAC Know It All, host Gary McCreadie talks with Chris Howells, Senior Training & Development Manager at AprilAire, about designing smaller filters and cabinets while maintaining filtration performance and airflow. In Part 2 of their conversation, they discuss three-inch media, one-inch MERV 11 filters, and installation practices that affect pressure drop. HVAC technicians will learn why filter depth alone does not determine performance and how transitions help systems use the filter's full face opening.

Howells describes more than four years of development work informed by contractor, distributor, and consumer feedback. He explains how AprilAire's engineering and product management teams addressed shrinking mechanical spaces through changes to media construction and cabinet design. He also shares field-testing experience that connects those design choices to airflow concerns and maintenance schedules.

Key Takeaways How smaller mechanical rooms and contractor feedback are driving thinner filter cabinets and changes to their dimensions.

How supporting mesh, electrostatic media, and adjustments to metal backing help three-inch filters retain surface area while limiting pressure drop.

The role of increased surface area and frame design in AprilAire's one-inch MERV 11 filter offering.

Why filter service intervals and field validation matter when matching filtration options to maintenance agreements.

How transitions that expose the full filter face help avoid pressure increases caused by undersized return openings.

Key Timestamps 00:00 – Factory Direct Filters Ad

00:42 – Episode overview and Guest introduction

02:22 – Cabinet evolution and demand for smaller dimensions

10:49 – One-inch MERV 11 filter design and surface area

15:03 – Full-face transitions, pressure drop, and replacement practices