ECONOMIZERS & MIXING BOXES
Economizers & Mixing Boxes — Practical Knowledge for Real-World HVAC Applications
Economizers and mixing boxes play a critical role in energy efficiency and ventilation strategy. When properly configured, these components help reduce operating costs by leveraging outdoor air conditions or recycling energy already present in the system. When misapplied or incorrectly set up, however, they can create performance issues, comfort complaints, and unnecessary energy waste.
At MicroMetl, we bring nearly 60 years of experience designing and manufacturing economizers and mixing boxes. Our goal is simple: break down these complex concepts into clear, approachable guidance that helps you make confident decisions in the field.
In this section, you’ll find easy-to-understand explanations, troubleshooting insights, and practical tips for optimizing airflow, controls, and system performance.
Have a question or a challenge you’ve encountered in the field?
Let us know—your topic may become the next feature in our multimedia blog.
Siemens POL224 Controller — Essentials for HVAC Economizers
Modern HVAC ventilation and economizer strategies require smarter, more connected controls. The Siemens POL224 (also marketed as Climatix ECO) controller is one of the advanced options on the market—offering improved diagnostics, network communication, flexible I/O,...
Economizer Types Defined
Economizers are essential mechanical components used to improve HVAC system efficiency by regulating the balance of return air and outside air. They help meet ventilation standards, reduce mechanical cooling demands, and lower overall energy consumption. Depending on...
What Is an Economizer — AKA a Mixing Box? Economizers Class 101
Saving Money and Lowering the Cooling Load is really what an economizer does. Webster defines economize as to “reduce expenses.” In its most simplistic form, an economizer is nothing more than a device which introduces fresh outside air into a building space in a controlled manner
Ultra Low Leak Economizers — What They Are and Why They Matter
What Is An Ultra Low Leak Title 24 Economizer? Title 24 Economizer Mandatory & Prescriptive Defined, Title 24 Section 120.2 & 140.4 Excerpt PDF
Barometric Relief — What It Is and How It Works
Barometric Relief What Is It And How Much Air Does It Remove? A reader recently asked; What is Barometric Relief, and how much air does it remove? It’s important to provide fresh, healthy air to a building’s occupants. Therefore, when
Mixing Boxes For Residential Applications
Many articles have been written about Night Air Cooling — AKA “Free Cooling.” Those articles explain how turning off the Air Conditioner (A/C), opening windows, or turning on a whole house fan at night can lower your energy bills… Have You Considered A Mixing Box? A Mixing Box offers the security of having your windows & doors closed and secured at night, yet provides “Free Outdoor Air Cooling.”
Economizer Installation Instruction Into A SRT Carrier, Bryant, ICP Rooftop!
Here are step by step instructions on how to install a Horizontal Economizer And/Or Vertical Economiser into A Carrier, Bryant, or ICP Rooftop! These are two great videos geared toward field technicians but can be used to train and educate customer service and...
California Title 24 Economizer Requirements – What You Need to Know
California’s Title 24 has shaped HVAC efficiency standards for more than a decade, and its influence continues to spread. Whether you are working in California or in a state adopting similar codes, understanding Title 24’s impact on economizers and ventilation control...
Honeywell JADE W7220 Controller — The Essentials
As codes and efficiency standards continue to evolve, the HVAC industry needs more reliable, intelligent economizer controls. Honeywell’s JADE W7220 answers that need with improved diagnostics, sensor communication, and code compliance—all in a user-friendly package...
Economizers: How to Set Minimum Position Correctly
Properly setting the minimum outside air position on an economizer is essential for comfort, energy efficiency, and code compliance. While controls explain how to adjust a minimum position, they don’t tell you where to physically set the damper blades to deliver the...
