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A Complete Guide to the Luna G3 Auto CPAP Machine

Updated 4/12/2023

We've noticed a lot of interest in the Luna series APAP machines by 3B Medical, especially since the Philips Respironics recall of the popular Dreamstation series. In response (and with the consent of their healthcare providers), many of our CPAP users have turned to alternatives to treat their obstructive sleep apnea. Chief among these are machines like the Luna 3 or the Resvent iBreeze APAP, both with an integrated heated humidifier. But do these machines deliver in terms of features and ease of use? Let’s take a deeper look at the Luna.

Overview of the Luna G3 APAP

 The Luna is an auto-titrating sleep apnea therapy device. It’s unlike a standard CPAP device, which maintains a consistent pressure setting throughout the night. The Luna 3 and other APAP machines monitor your breathing and adjust the pressure level accordingly (but always within your prescribed range). This ideally helps reduce visits back and forth to your doctor to adjust pressure.

An APAP machine always provides the minimum pressure needed to keep your airways open. This is a huge plus for CPAP patients who are light sleepers or who are new to CPAP therapy. It can also adjust to temporary blockages such as those caused by allergies or a cold, increasing pressure to clear the airways effectively.

It’s important to consult with a doctor on which machine is right for you, whether it’s an APAP, CPAP, or BiPAP. Certain conditions (like central sleep apnea) respond differently to different types of machines. But it’s certainly worth asking about, especially if you need a range of pressure settings as opposed to just one level, or if you find it difficult to exhale with a CPAP.


The Luna offers advanced features comparable to its more expensive competitors at a lower price point. It also includes the same 2 year warranty as those other models. Below are some of the most popular features that help the Luna stand out.

Built-in Heated Humidifier

Humidification is a popular comfort setting for CPAP users, and can be a lifesaver during allergy season or cold, dry months. Moisturized air helps to soothe nasal passages and airways, helping to break up congestion, reduce irritation, and prevent dry mouth.

The humidification setting is indicated by small blue bars on the LCD display, which you can adjust up or down with the control knob. The levels go from 1-5, or turned off altogether. While the Luna 3 does not come with heated tubing, you can purchase it separately.

Reslex® Expiratory Pressure Relief (EPR)

The Luna lowers air pressure on exhalation so users aren’t fighting against incoming airflow as they breathe out. This helps create a more natural breathing sensation. You can set the Reslex EPR on a range from 1-3, with 1 offering the smallest reduction in pressure, and 3 being the biggest reduction. You can also leave this feature off altogether if you’d like.

Intuitive Interface

The 3.5” full color backlit LCD screen is located on the top of the Luna II cpap machine. It’s easy to navigate through all the comfort settings as well as your last session’s therapy data using the single dial menu and two buttons. The screen displays stats like compliance hours, average pressure, AHI, snore index, and leak rate.

You can also choose your mask type here, whether it’s a nasal, nasal pillow, or full face mask. Note that the screen will go dark about about 20 seconds, but can easily be awakened by pressing the button.

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Auto Start/Stop

Simply put on the mask and start breathing to begin therapy, and take it off to stop without losing your comfort settings. No need to reset the machine each time you get up through the night!

Quiet Operation

Consumers have gotten used to their CPAP machines operating at a very low volume for a few years now as sleep therapy technology evolves. At just 26 decibels, the Luna G3 is quieter than a whisper when running.

Sleep Therapy Data Access

The Luna Auto PAP supports wi-fi connectivity so you can easily access and share your compliance data with your healthcare provider. Simply navigate to the iCode section and choose your report type and the machine will display a code. Plug that code into an iCode app on your phone or online to view or download your report. There is also a QR code you can scan.

Mask Leak Detection

Another feature that is unavailable on the Dreamstation and similar models, leak detection can sense when your CPAP mask begins to leak air. These leaks can not only cause dry mouth and irritation, they can reduce the air pressure flowing to your airways. The Luna is equipped with a handy mask leak alert that will let you know when there’s an issue.

Longer Ramp Time

While the DreamStation and comparable models only provide a maximum of 45 minutes of ramp time, the Luna APAP offers 60! You can set the ramp feature to run for however long you want, from 5-60 minutes in 5-minute increments.

Setting up the Luna Auto CPAP

Upon unboxing your 3B Medical Luna G3 Auto CPAP, you’ll find everything tucked into a sleek, padded carrying case that has a compartment for everything and visual cues for what goes where. There will be the machine with water chamber, tubing, air filter, user manual, AC power cord and power adapter.

Simply connect the machine to the power supply and plug into an outlet. The LCD screen will light up and indicate the machine is powered on. Place the machine on a nightstand or flat surface and connect the CPAP tube to machine air outlet and CPAP mask.

Pros and Cons

Though it’s fairly compact, this machine is a bit heavier and larger than popular models like the ResMed AirSense 10. The unit with built-in humidifier has dimensions of 10.7”x7.2”x4.5” and a total weight of 3.75 pounds. That’s compared with dimensions of 10”x4.6”x5.9” and a weight of under 3 pounds for the AirSense 10. At this time, Luna APAP doesn’t have a battery option either, so it’s not ideal for travel.

The biggest pro of the Luna Auto CPAP is the price; ideal for budget conscious users who want comparable features to some of the higher end models for less. The extended ramp time and mask leak detection are the two other major pros that our customers appreciate, especially at the lower price point.