CPAP Therapy Tips

Z2 Auto CPAP Machine Review—With Scores and Rankings

The Z2 Auto Travel CPAP Machine from Human Design Medical was released in 2019 and is very popular among the people that have tried it. The secret? When compared to its predecessor, the Z1 Auto, the Z2 is 29% quieter and has a different pitch to the motor. It’s also value-priced at around $589, making it an attractive option for busy travelers.

How does it stack up against the competition? Read on to find out!

Our Ratings for the Z2 Auto Travel CPAP Machine

Noise Level – 7

The Z2 Auto checks in at 26 decibels, but the pitch of the motor is much improved over the Z1, and that’s a big difference here. Because of the improvement in this area, the Z2 is rated highly. It’s a quieter CPAP machine, and the free Q-Tube Muffler is nice.

Other Machine Noise Level Scores
DreamStation Go4
Transcend Auto6
Z1 Auto6

Cost – 9

The Z2 Auto is a little more expensive than the Z1 but is still value-priced compared to other machines in the travel category. It also comes with a lot of nice freebies, like a free Q-Tube CPAP Muffler and a Heat Moisture Exchange Unit (waterless humidification).

Other Machine Cost Scores
DreamStation Go6
Transcend Auto9
Z1 Auto7

Warranty – 8

The 2-year warranty is what most CPAP machines have. It covers manufacturer defects and mistakes, but not misuse or abuse. The Z1 Auto has a warranty of 3 years, which is an industry leader. Ultimately, we awarded the Z2 the same score as other machines that also have a 2-year warranty.

Other Machine Warranty Scores
DreamStation Go8
Transcend Auto9
Z1 Auto9

Weight – 9

You can measure the weight of the Z2 in ounces, not pounds. It weighs in at 10.4 ounces, which is a nice weight for a travel machine. It’s roughly the same as the Z1 Auto, so we rate the Z1 highly in that category too.

Other Machine Weight Scores
DreamStation Go9
Transcend Auto9
Z1 Auto9

Size – 9

The machine is a nice size travel CPAP machine and is roughly the same size as the Z1. It can fit into almost any travel bag, and go anywhere you need.

Other Machine Size Scores
DreamStation Go9
Transcend Auto9
Z1 Auto9

Pressure Relief – 9

The Z2 Auto has Z-Breathe Pressure Relief, along with auto-adjusting pressure, making it easy to exhale. The other machines we looked at also have Pressure Relief and auto-adjusting pressure, so we awarded them a similar score.

Other Machine Pressure Relief Scores
DreamStation Go9
Transcend Auto9
Z1 Auto9

Therapy Tracking – 9

The Z2 Auto allows you to download your results to your Windows computer for further analysis. You can also review your therapy results on your phone using the Nitelog Mobile App. When compared to other machines, the therapy tracking features of this machine stacks up well.

Other Machine Therapy Tracking Scores
DreamStation Go9
Transcend Auto3
Z1 Auto9

Humidification – 8

The Z2 Auto includes a Heat Moisture Exchange Unit, which is similar to ResMed’s HumidX and recycles humidity from exhaled breath to create the sensation of moisture without needing water-based humidification.

Other Machine Humidification Scores
DreamStation Go8
Transcend Auto5
Z1 Auto5

Smart Features – 8

The Z2 Auto has auto-start and auto-stop and is similar to the Z1 Auto. The DreamStation Go and AirMini are comparable to each other in terms of smart features, and the Z2 comes close but doesn’t have all the extras.

Other Machine Smart Features Scores
DreamStation Go9
Transcend Auto8
Z1 Auto8

Battery – 9

Both the Z1 and the Z2 have a battery that’s been custom-tailored to its needs: the Z1 and Z2 PowerShell Battery. The battery works with both machines. In fact, the Z2 can use all of the Z1’s same accessories. This is similar to the DreamStation Go, which also has a companion battery that’s designed specifically for it.

You can also connect to the Z2 with the Pilot-12 Lite and the Z1 and Z2 Mixed Cable Kit. You can also use the Portable Outlet CPAP Battery, which is capable of powering any device with a power supply and plug! The Portable Outlet can also be used with humidification, making it a versatile and flexible battery.

Other Machine Battery Scores
DreamStation Go9
Transcend Auto8
Z1 Auto9

TOTAL SCORE: 86 / 100 or 86%

Total Scores for Other Machines
DreamStation Go79
Transcend Auto71
Z1 Auto81


Overall, the Z2 Auto scored very well across the board and stacks up well against similar travel machines. Ultimately, the differences in noise level and humidification options are the things that separate the Z1 and the Z2. For just a little more money, you’ll get a quieter machine with lots of freebies from the manufacturer that makes this a great buy at around $580.

David Repasky has been using CPAP treatment since 2017 and has first-hand experience with what it’s like to live with Sleep Apnea. He brings the patient’s perspective to the blog and has received formal training in CPAP machines, masks, and equipment.


  1. The review was inaccurate with respect to the smart features. The Nitelog app does not function with the Z2. The reviews from users of the Z1 are terrible. The app itself looks like a first generation iPhone app and has not been updated in 3-4 years despite constant complaints from users. Very odd.

    • Hi Craig, thank you for your feedback. I have contacted Human Medical Design, the manufacturer of the Z1 and was advised that the Nitelog App does in fact work with the Z2. I was also advised that they are in the process of re-designing the Nitelog App. If you are experiencing issues with utilizing the app, please reach Human Medical Design at: 855-436-8729 for technical assistance.

      We value all customer feedback, please feel free to reach us at: 1-800-356-5221 with any further questions, or concerns.

      Enjoy your day!

  2. Hi Craig,
    This may be obvious to everyone but me, but how do I interpret the scores?
    Is 1 the highest or is 10 the highest score?
    Is it possible to upgrade my noisy Z1 to a Z2 without paying full price?
    I can’t even use the Z1 because the noise keeps me awake.

    • Hi Mike, that’s a great question! For this article, 10 is the highest. The higher the score the better the ranking is.

      Did you purchase your Z1 from within the last 15 days? If so, it is under a guarantee/trial period and you may return it for the Z2 and only pay the difference in cost.

      If you purchased your Z1 from a different company, you should verify what their return policy is.

      Please feel free to reach us at: 1-800-356-5221, or you may e-mail us at: with further questions, or concerns.

      Have a wonderful day!

  3. Stephen goldberg Reply

    I have a z1 and an air mini. I would rate the house if the z1 at 3 and the air mini at 9 since you can barely hear the air mini.

  4. James Smith Reply

    I have a Z2 Auto. It’s a very good travel machine, and it is somewhat quieter than the Z1, which I also had prior to the Z2.

    There is still some noise, but it’s much improved. Noise is also impacted by your choice of mask and tube. I found that full size 19mm tubing is quieter.

    Regarding the App – it works exactly the same on the Z2 as the Z1. It definitely needs tweaking. The biggest challenge is getting the app to connect to bluetooth. When you get the connection screen, it seems to see every device in the neighborhood, and the screen scrolls quickly which makes it hard to connect. Once you get the hang of it you can get connected. If you want more data, they have a Win 10 compatible program that has much better data than the mobile app. Having said that, the Nightlog app, and their Windows app have much more info than Resmed My Air. All in all I like the unit.

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