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The latest industry insights from the pros at AirReps.

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Understanding A2L Refrigerant Leak Detection and Mitigation in Daikin Rebel and Rebel Applied Rooftop Units

With the HVAC industries transition to lower Global Warming Potential (GWP) refrigerants, A2L refrigerants have become the current standard in commercial rooftop systems. While these refrigerants offer environmental advantages, they also introduce new safety requirements due to their mildly flammable classification. Daikin Applied’s Rebel and Rebel Applied Packaged Rooftop Units, equipped with the MicroTech® Unit Controller, address these challenges through a sophisticated A2L leak detection and mitigation system designed to maintain safety, system reliability, and compliance.    What Is the A2L Leak Detection System?  Daikin’s factory-installed...

Kurt Schultheis

June 23, 2026

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Rebel + Rebel Applied 

Understanding A2L Refrigerant Leak Detection and Mitigation in Daikin Rebel and Rebel Applied Rooftop Units

With the HVAC industries transition to lower Global Warming Potential (GWP) refrigerants, A2L refrigerants have become the current standard in commercial rooftop systems. While these refrigerants offer environmental advantages, they also introduce new safety requirements due to their mildly flammable classification. Daikin Applied’s Rebel and Rebel Applied Packaged...

Kurt Schultheis

June 23, 2026

Daikin VRV

Bleeding By Daikin VRV EEVs

What does A9-02 mean? Whenever working on any Daikin VRV system, there is always a possibility of generating an A9-02 error code. This code indicates that an indoor fan coil is experiencing refrigerant bleed-by. In this instance liquid refrigerant is...

Ivan Balbuena

June 8, 2026

Daikin VRV

VRV System Not Communicating? Here’s What We Check First

Whether the system is missing indoor units, throwing U4 alarms, or not seeing devices correctly, the issue is usually related to communication wiring, addressing, or controller setup.  Before getting too deep into troubleshooting, we typically start by verifying the communication...

Connor Sawyer

May 18, 2026

Daikin VRV

Understanding the U4 Error Code in Daikin VRV Systems

Understanding the U4 Error Code in Daikin VRV Systems  If you’re seeing a U4 error code on your Daikin Variable Refrigerant Volume (VRV) system, you’re dealing with a communication issue that needs prompt attention. This error is one of the most common diagnostic codes...

Matt Bayley

May 7, 2026

Daikin VRV

Daikin VRV, A2L requirements, 2021 IMC, and ASHRAE 15

Our team of HVAC experts at AirReps has now been through several Daikin VRV projects across Washington under A2L requirements, and the process is starting to become more consistent. The code framework itself, including the 2021 IMC and ASHRAE 15, is well established. What has taken...

Justin Sipe

April 22, 2026

Velo

Stabilizing Performance and Reducing Swing Tank demand with the new generation of Domestic HWHPs

As the era of decarbonization brings focus to the domestic hot water production of buildings, heat pumps have become the leading technology utilized to achieve this goal with great success.  Fossil fuels can be removed from systems and high COPs can be achieved, even as...

Colin Holt

March 26, 2026

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