Comparing Mitsubishi 410A Models to 454B Models

With the current change over from 410A refrigerant to new 454B refrigerant and R-32, we know it’s a confusing time for Massachusetts consumers looking to upgrade to heat pumps! In any effort to help educate consumers and allow you to easily compare quotes that you may be getting from multiple HVAC contractors, we’re breaking down the differences for Mitsubishi heat pumps in each refrigerant.

The Geeky Chart

Everyone loves a chart, right? The below chart shows efficiency and GWP improvements with 454B – 78% lower than 410A models.

Three New Features that We Love

• Wifi! Two words – wifi included! Mitsubishi had been a bit of a hold out from other heat pump brands in including built-in wifi on its systems. With the introduction of the 454B equipment wifi is now included!
• Lower minimum capacity on 36k Multizone: Another exciting improvement is the lower minimum capacity on the 4-port 36,000 BTU multizone system (MXZ-SM36NLHZ), which is one of the most commonly installed systems. While this might sound a bit technical to some customers, it’s actually a big deal. A known issue with Mitsubishi multizone systems has been the tendency to overheat, partly due to the higher minimum capacity of 22,500 BTU on the 410A models. The new system lowers that minimum to just 12,600 BTU—almost half. This means that if you have a ductless wall unit in a smaller room, you’re much less likely to experience the overheating issues that some customers have reported in the past.
• Introducing Mitsubishi Zuma: Some of the models (referred to as Mitsubishi Zuba models) now operate at 100% at 3 degrees and function down to lower temperatures of -22 (perviously it had been -15!). In Massachusetts its extremely rare to see in the single digits let alone in the negative – meaning these models are more than capable of heating your home in the Massachusetts winter.

One Thing We Don’t Totally Love

• Branch Boxes: As we’ve seem an increase of brands avoiding branch boxes, Mitsubishi continues to require branch boxes for its multizone systems that are 30K BTUs and above. While we understand why Mitsubishi leverages branch box (long story short – it allows for more length and flexibility in overall design), branch boxes are one of the highest, if not the highest areas of install error out there! However, a good installer should mostly be able to avoid these errors.

A Partial List of Mitsubishi Model Number Changes from 410A to 454B Systems

We’re including this because we’ve seen customer received quotes from peer HVAC contractors in both 410A and 454B. Below is a simple chart that compares Mitsubishi 454B to the older 410A models, so when you are comparing quotes you can make sure you are comparing the same thing. One caveat – this is by no means all inclusive for Mitsubishi and was updated on 4/30/2025!

One final note if you are considering putting in a Mitsubishi heat pump system: while the equipment is great, a great installation is also critical to the operation of these systems. We strongly encourage you to work with a Mitsubishi Diamond Elite Contractor (shameless plug – Endless Energy is a Mitsubishi Diamond Elite Contractor!).

If you’d like to schedule a no cost consultation for a Mitsubishi ducted heat pump or Mitsubishi ductless heat pump, book your appointment directly online here or give us a call at 508-501-9990.