CPAP Water Tank Buddy (Airsense 11)

Fill your Airsense 11 water tank to the highest level without spilling! Increases the total fill by 27%!

(This is my first post, let me know if I missed anything important)

Like many other Airsense 11 owners, I find that the water tank is too small and I run out of water before I wake up. It doesn't help that the rim height differs between the front and back of the tank, making it harder to fill without spilling. I quickly found that if you fill the tank at an angle, you can maximize the amount of water you can get in the tank.

After using some stacked coasters for a while, I wanted a simple solution to keeping the tank at an angle while I fill it. I remixed this from Mhatey3D's Parametric Leveling Wedges and added a tab to keep the tank from sliding while filling and some extra bulk near the bottom for more strength. After a few test prints with different dimensions, I fell on 135mm*80mm*24mm as a nice size for this use case. That size puts the filling angle at just over 10 degrees. I've tested for a few nights now and I'm definitely getting more mileage out of my water tank when filling with the Tank Buddy.

I'm publishing this here hoping my solution to this little issue can help some other people out.

(I printed mine with the X1C. Please let me know if you experience issues with another printer, I'll do what I can to assist 🙂)

Specifications

Size: 135mm long * 80mm wide * 24mm tall

Fill Angle: 10.08°

Fill Comparisons

330mL - When filled on a flat surface

380mL - The official “max” advertised by ResMed

420mL - Fill amount when using Tank Buddy

90mL more than filling on a flat surface

Instructions

Place the water chamber on the Tank Buddy with the latch side against the vertical tab at the bottom of the slope. Fill with water until you reach near the top of the inner lip of the latch side. Be sure to close your water chamber before removing from the Tank Buddy or you're likely to spill. (Note that when filled to the very edge of spilling with this assistant, you may hear gurgling from your machine for the first few breaths but that should go away quickly.)