ResMed AirFit F40: Hands-On Review 2026

ResMed AirFit F40: Full Guide and Review

The ResMed AirFit F40 represents a new generation of full-face CPAP masks. While traditional full-face masks cover the nose and mouth with a large footprint, the AirFit F40 takes a minimalist approach. A small under-the-nose cushion, a completely open field of vision, and an open design that appeals to claustrophobic patients or glasses wearers.

VivaRespire is a specialist online CPAP store. We do not offer INAMI reimbursement. For information on the Belgian convention, see our page CPAP reimbursement in Belgium.

What Is the AirFit F40?

The AirFit F40 is a "minimal contact" or "under the nose full face" mask. Unlike traditional full-face masks, its cushion sits below the nostrils rather than around the nose perimeter. It still covers the mouth, making it suitable for mouth breathers, just like a conventional full-face mask.

It comes in three sizes: XS, S and M, and is suitable for both men and women.

Key Technical Features

  • Type: minimal-contact full-face mask (under the nose)
  • Cushion: soft silicone, small format
  • Headgear: 4-point anchor, quick-adjust
  • Field of vision: completely unobstructed
  • Weight: very lightweight
  • Compatible: all ResMed CPAP devices and other standard brands
  • Sizes: XS, S, M

Advantages of the ResMed AirFit F40

1. Minimal facial footprint

The AirFit F40 cushion does not cover the eyes or cheekbones. Patients who felt oppressed by large full-face masks often find this mask a far more tolerable alternative.

2. Completely open field of vision

You can read, watch your tablet or phone with the mask on, without any obstruction to your vision. This is a notable advantage over conventional full-face masks.

3. Ideal for glasses wearers

Since the frame does not extend up to the eyes, you can keep your glasses on while fitting the mask, making adjustment easier.

4. Suited to claustrophobic patients

The open design reduces the enclosed feeling often associated with standard full-face masks, while still covering the mouth for mouth breathers.

5. Lightweight and discreet

The small mask size makes it less bulky on the face, which makes falling asleep easier and reduces contact with the pillow.

Disadvantages of the ResMed AirFit F40

  • Under-nose seal: the under-nostril position requires careful fitting. Poor adjustment leads to more frequent leaks than a nasal or nasal pillow mask.
  • Beard: like all full-face masks, a beard can compromise the seal. See our guide on CPAP masks for beards.
  • Pressure under nostrils: some patients feel slight pressure under the nostrils from the cushion position.
  • Limited sizes: only XS, S and M - no large L size.

Comparison: AirFit F40 vs Traditional Full-Face Masks

Criterion AirFit F40 AirFit F20 / AirTouch F20
Facial footprint Minimal (under nose) Full (nose + chin)
Field of vision Completely free Partially obstructed
Claustrophobia Better suited Less suited
Glasses Compatible Uncomfortable
Beard Difficult (under-nose seal) Difficult (full-face seal)
Available sizes XS, S, M XS, S, M, L
Mouth breathing Compatible Compatible

Who Is the AirFit F40 Best For?

The AirFit F40 is particularly recommended for:

  • Patients with mild to moderate claustrophobia with conventional full-face masks.
  • Glasses wearers who want to fit their mask while seeing clearly.
  • People who watch TV or read before sleeping with their CPAP on.
  • Patients who sleep mostly on their back and move little during the night.
  • Mouth breathers who cannot adapt to nasal or nasal pillow masks.
The AirFit F40 is not the best choice for side sleepers: the under-nose cushion can shift when lying on your side. See our guide on CPAP masks for side sleepers.

Maintaining the AirFit F40

The silicone cushion can be washed daily in warm water with mild soap. The frame and headgear can be cleaned several times a week. Replace the cushion every 1 to 3 months depending on visible wear.

See Also

Frequently asked questions

How is the AirFit F40 different from the AirFit F30 and F20?

The AirFit F20 is a classic full-face mask: the cushion covers nose and mouth, wrapping the full nose perimeter. The AirFit F40 takes a minimalist approach: its cushion sits below the nostrils while still covering the mouth. The AirFit F30 is even more compact and only covers the mouth and the base of the nose. The F40 is the best compromise for mouth breathers who want an open design.

Is the AirFit F40 suitable for side sleepers?

Not ideally. The under-nose cushion can shift in side position, especially if you toss a lot at night. Side sleepers tend to do better with a mask that has its air connection on top, like the AirFit F30i, or a nasal pillow mask like the AirFit P10. For back sleepers or those who barely move, the AirFit F40 remains a great fit.

What are the downsides of the AirFit F40?

Three points deserve attention. First, the under-nostril seal requires careful fitting: a poorly positioned mask leaks more than a classic AirFit F20. Second, some patients feel slight pressure under the nostrils for a few days while getting used to it. Third, only three sizes exist (XS, S, M) with no large L, which may limit larger faces.

Is the AirFit F40 compatible with the AirSense 11?

Yes, perfectly. The AirFit F40 uses a standard 22 mm connection. It is compatible with the AirSense 11 AutoSet and Elite, the AirSense 10, the DreamStation 2, the Löwenstein prisma SMART and all standard CPAP devices. It also works with the ClimateLineAir 11 heated tube. You can pair it with your current ResMed device without issue.

Which AirFit F40 size should I choose?

ResMed provides a sizing guide to measure the distance between the base of the nose and the chin, plus the width of the nose base. Most adult men take size M, most women S, and finer faces XS. The best approach is to download the official ResMed sizing guide and apply it to your face. If in doubt, get in touch with us.

How do you properly clean the AirFit F40?

The silicone cushion is washed daily in warm water with a mild soap, neither antibacterial nor moisturising. Rinse thoroughly and let it air-dry, away from direct sun. The frame and headgear are washed 1 to 2 times a week. Avoid alcohol, vinegar and aggressive products that degrade silicone. Replace the cushion every 1 to 3 months depending on wear, and the headgear every 6 to 12 months.

Does the AirFit F40 work well with a beard?

A beard complicates the seal of any full-face mask, and the AirFit F40 is no exception. With a short, even stubble, sealing stays acceptable. With a thick, long beard, expect more frequent leaks around the chin and under the nostrils. In that case, a nasal pillow mask like the AirFit P10 may suit you better since it does not contact the beard.

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