ResMed Machine vs Breas travel CPAP

I regularly use the ResMed CPAP machine which works well for me. A few years ago before a trip to the UK I bought the Breas Z2 travel CPAP which I use when traveling. I just have a question. When I use the ResMed, air is continuously flowing from the hole in the air "pillow" below the openings that go in my nostrils. When I use the Breas, air only comes out of that hole when I exhale. I'm just curious about why the difference.
By the way, I want to thank the moderator (as I recall) for giving me the tip to moisten the Heat Moisture Exchanger (HME) for the Breas. When I first tested it, my nose was burning from not enough moisture. I just wish I could take the HME apart for easier cleaning of the sponge inside after a trip.

1. Which mask models are you using for each machine?

2. When you say, "

s_beecher1 wrote: ↑

Wed Oct 08, 2025 1:21 pm

flowing from the hole in the air "pillow" below the openings that go in my nostrils

, do you mean the mask is leaking?

3. Do you feel you sleep better or feel better with one machine versus the other?

I use the same mask with each machine. It is the Phillips Respironics Dreamwear silicone pillows mask. It is not leaking. It allows air to flow out via a small slit right under the "pillows" that go in my nostrils.

I find that both devices work fine for me. I made the Breas match the settings of my Resmed.

s_beecher1 wrote: ↑

Wed Oct 08, 2025 1:21 pm

When I use the ResMed, air is continuously flowing from the hole in the air "pillow" below the openings that go in my nostrils. When I use the Breas, air only comes out of that hole when I exhale. I'm just curious about why the difference.

Air should be flowing out of that slit (exhalation port) at all times on either machine. It's likely flowing at a much lower rate when you inhale. If you inhale deeply, it might not flow at all.

Remember, your observations are when you are awake. You don't know what is happening when you are asleep.

Here is some explanation of the exhalation ports --->

Exhalation ports: The mask includes built-in exhalation ports, located both on the cushion and at the top-of-head swivel elbow. These ports silently disperse your exhaled carbon dioxide, ensuring you only breathe in fresh, pressurized air.

Agree (mostly) with CG.

Simply put, you can push air into the CPAP without it coming out somewhere.

Use the back of you hand very close to the vent, you should always feel venting and it should be warmer when you exhale.

ChicagoGranny wrote: ↑

Thu Oct 09, 2025 11:07 am

It's likely flowing at a much lower rate when you inhale. If you inhale deeply, it might not flow at all.

If any kind of pressure relief is used, you will feel more venting during inhalation as the device will increase the pressure.

The difference between your Z2 could be the difference between ResMed's EPR and Breas' Z-breath.

Dog Slobber wrote: ↑

Thu Oct 09, 2025 2:49 pm

The difference between your Z2 could be the difference between ResMed's EPR and Breas' Z-breath.

Besides the pressure relief, we forgot to ask him if he is using the same pressure(s) on each machine.

I followed the settings on my resmed CPAP to set up the Breas. (Obviously, the durable medical supply place wasn't willing to help me set this up since I didn't buy it from them.)
Thanks to everyone who explained about the openings on my mask that allow carbon dioxide to be released. I need to use the Breas again and see if there is some air coming out when I'm not exhaling.