Nasal CPAP Masks: AirFit N20 vs N30i
Nasal CPAP Masks: AirFit N20 vs N30i
Nasal masks are smaller, lighter and less claustrophobic than full face masks — but only if they suit the way you breathe. Here's how to tell whether a nasal mask is right for you, and which of these two will solve your particular problem.
Jump to what matters to you.
A nasal mask works brilliantly — if you breathe through your nose.
A nasal mask delivers therapy through your nose only. That's its great strength and its one real limitation. It covers far less of your face than a full face mask, so it's lighter, less obtrusive and often far easier to sleep in. Many people who struggled with a full face mask find a nasal mask transforms how they feel about CPAP.
The limitation is simple physics. If your mouth falls open while you sleep, the air pushed in through your nose escapes straight out of your mouth. The machine can't hold its pressure, therapy stops working properly, and you wake with a dry mouth and a sore throat. For a nasal mask to work, your mouth needs to stay closed — or be helped to stay closed.
If you're on the fence, the dry-mouth test is the most useful single clue: a mouth that's parched in the morning almost always means air has been escaping through it overnight. Our guide to choosing a full face mask covers the other side of the decision. Everything below assumes a nasal mask is a sensible choice for you — and then helps you pick between the two most popular ResMed designs.
The two masks we're comparing
The AirFit N20 is a classic nasal mask: a cushion that covers your nose, with a short tube at the front. The AirFit N30i is a nasal cradle mask: a small cushion that sits under your nose, with the tube connecting on top of your head. Both are ResMed masks, both connect to standard CPAP tubing, and both are widely used in the UK. They suit quite different people.
Find your mask in two questions.
Start at the top. The detail for each answer is further down the page.
On a phone, swipe sideways to see the whole chart.
AirFit N20 and N30i compared.
| AirFit N20 | AirFit N30i | |
|---|---|---|
| Style | Nasal mask — cushion covers the nose | Nasal cradle — cushion sits under the nose |
| Cushion | InfinitySeal silicone | Silicone cradle |
| Tube connects | Short tube at the front | Top of the head |
| Nose bridge | Cushion sits on the nose | Nothing on the bridge |
| Cushion sizes | Small, Medium, Large · For Her variant | Small, Medium, Small Wide, Wide |
| Frame sizes | One frame for all cushion sizes | Standard and small |
| Headgear fastening | Magnetic EasyClick clips | Tabs fastened to the frame |
| Side sleeping | Cushion designed to accommodate movement | Therapy continues on your side through the other side of the frame |
| Best for | A forgiving, stable seal; first nasal mask | Minimal feel, restless sleepers, sore nose bridge |
On a phone, swipe the table sideways to see both masks.
As with every mask, fit beats features. The right size of either mask will outperform the wrong size of the "better" one. Use this guide to decide which design suits your problem, then let fit settle the rest.
What's bothering you?
| If this sounds like you… | Look at | Read |
|---|---|---|
| Your full face mask feels bulky or claustrophobic | N30i, N20 | Problem 1 |
| Red marks or soreness on the bridge of your nose | N30i | Problem 2 |
| You toss and turn, or the hose drags the mask | N30i | Problem 3 |
| You can't get a reliable seal | N20 | Problem 4 |
| You wake with a dry mouth | Possibly a full face mask | Problem 5 |
| Your nose is often blocked | A backup plan | Problem 6 |
| You or your partner have an implanted device | Read the safety section first | Safety |
Your full face mask feels like too much.
It covers half your face. You feel shut in the moment it's on. It's heavy, it shifts, and you're starting to dread bedtime.
Precautions first
Check whether you need full face at all. If you wake with a comfortable mouth and your nose is usually clear, a nasal mask may well work for you — but ask your clinic, especially if they prescribed full face for a reason.
Practise while awake. Twenty minutes with the mask on and the machine running, while watching television, takes much of the strangeness out of it.
Use the ramp feature so pressure builds gently as you fall asleep.
Our guide on feeling trapped in your mask covers the full set of techniques.
Which mask helps
Either nasal mask covers far less of your face. The AirFit N30i is the more minimal of the two: a small cradle under your nose and the tube routed over your head, leaving your face largely clear. The AirFit N20 is a more traditional nasal mask that many people find reassuringly stable.
Red marks and soreness on the bridge of your nose.
A red line across your nose every morning. Tenderness when you put your glasses on. Skin that never quite gets the chance to recover.
What you're suffering
The bridge of the nose has very little padding between skin and bone, so it's the first place to suffer from a mask that presses. Marks that fade by mid-morning are a nuisance; marks that are still there at lunchtime, or skin that starts to break down, are a sign something needs to change.
Why it happens
Masks that sit on or over the nose put some pressure on the bridge by design. That pressure rises sharply when straps are over-tightened — usually to chase a leak — or when a worn cushion has lost its shape and needs more tension to seal.
Precautions first
Loosen the straps. Refit lying down with the machine running, and tighten only until the leak stops.
Replace a worn cushion before tightening further. A fresh cushion seals with far less tension.
Check the size. A cushion that's the wrong size presses in the wrong places.
See your clinic if skin breaks or blisters.
Which mask helps
The AirFit N30i sits under the nose, so there's nothing on the bridge at all. For people whose main problem is marks or soreness there, changing to an under-the-nose design is usually the most effective fix of all — far more effective than endless strap adjustments.
You toss and turn, and the hose drags the mask.
You roll onto your side and the tube pulls the mask out of place. You wake to a hiss, refit it, and do it all again an hour later.
What you're suffering
Restless sleepers and side sleepers have the hardest time with masks that have the tube at the front. Every turn levers the mask, breaks the seal and wakes you. Some people end up sleeping rigidly on their back to avoid it — which is uncomfortable, and for many people makes sleep apnoea worse.
Why it happens
A front-mounted tube acts as a lever on the mask. When you move, the hose catches on the bed or your arm, and the force goes straight to the cushion. Pillows push side sleepers' masks off their seal too.
Precautions first
Route the hose above you, over the headboard or from a simple hook, so it hangs down to you rather than trailing across the bed.
Fit the mask lying on your side, in the position you actually sleep in.
Check your elbow swivels freely. A stiff swivel passes every movement to the cushion.
Try a CPAP pillow with cut-outs so the mask isn't pushed when you lie on your side.
Which mask helps
The AirFit N30i was designed with this in mind. Its tube connects on top of your head, so there's no hose at the front of your face to drag. ResMed describes it as designed for a range of sleeping positions, and notes that therapy continues when you lie on your side, with airflow compensated through the other side of the frame.
You can't get a reliable seal.
Hissing around the cushion. Air blowing into your eyes. A leak figure in your app that refuses to settle, however carefully you fit the mask.
Precautions first
Rule out your mouth. With a nasal mask, air escaping through an open mouth shows up in your data exactly like a mask leak. If you wake with a dry mouth, read Problem 5 before changing anything else.
Replace the cushion if it's soft, sticky, cloudy or more than a couple of months old.
Check the headgear for stretch; it typically lasts around six months.
Loosen, then refit lying down with the machine running. Over-tightening creases the cushion and creates new leaks.
Watch the trend in your data rather than single nights — our guide to reading your CPAP data explains the patterns.
Which mask helps
If you've ruled all that out and still can't get a seal, the AirFit N20 is the forgiving choice. ResMed designed its InfinitySeal cushion to "fit everyone, tolerate misfitting and accommodate patient movement", and reports that in its own study the cushion fitted 99.4% of the patients tested. In plain terms, it's built to keep sealing when the fit isn't perfect.
You wake with a dry mouth.
Your mouth is parched every morning, your throat is sore, and you're reaching for water the moment you wake. With a nasal mask, this usually means one thing.
What you're suffering
A dry mouth with CPAP is one of the most common complaints of all, and it's more than an annoyance. Overnight dryness can affect your teeth and gums, and the sore throat that comes with it makes therapy feel like a punishment.
Why it happens
With a nasal mask, therapy only works while your mouth is closed. If your mouth falls open in sleep, the pressurised air goes in through your nose and straight out through your mouth, drying everything on the way. Your machine may also record it as a leak, because air is escaping.
Precautions first
Rule out a mask leak. A leaking cushion also dries the air. Fit a fresh cushion and check the seal first.
Turn your humidity up one step for a few nights. It eases the symptom, though it won't fix an open mouth.
Try a chin strap test. A few nights with a chin strap is a cheap way to find out whether mouth opening is the cause. If your mouth feels much better, you've found it.
Ask your clinic whether a full face mask would suit you better. If you're a confirmed mouth breather, it's usually the more comfortable long-term answer.
Which mask helps
This is the one problem where the honest answer may be not a nasal mask at all. If a chin strap doesn't solve it, a full face mask covers your nose and mouth, so you can breathe through either and therapy keeps working. Our full face mask guide helps you choose one, and our guide to CPAP side effects covers dry mouth in more depth.
Your nose is often blocked.
Hay fever every summer, a cold every winter, or a nose that's simply stuffy at night. On those nights, a nasal mask feels impossible.
What you're suffering
A nasal mask needs a clear nose. When yours is blocked, you can't breathe through it, your mouth falls open, and therapy stops working. Many people simply skip CPAP until the cold passes — which means nights of untreated apnoea on top of feeling ill.
Why it happens
Congestion from colds, allergies or a structural issue narrows the airway through the nose. Dry air makes it worse, and in British winters, central heating and cold bedrooms combine to dry the nose out further.
Precautions first
Raise your humidity while you're congested; moist air is easier on an inflamed nose.
Use a saline spray or rinse before bed. A pharmacist can advise on decongestants and how long they're safe to use.
Sleep slightly propped up on a wedge to help drainage.
See your GP if your nose is blocked most nights, or if congestion lasts more than a couple of weeks. Persistent blockage is worth investigating properly.
Which mask helps
Keep your nasal mask for normal nights, and keep a full face mask in the drawer for blocked ones. It's the single most practical way to avoid losing a week of therapy to every cold. If your nose is blocked most of the time, a full face mask may suit you better as your main mask. Our winter CPAP guide covers congestion and dry air in more detail.
Magnets and implanted medical devices.
The one precaution in this guide that's about safety rather than comfort.
Getting the size right.
The N20 comes in Small, Medium and Large, and all three cushion sizes click into the same frame. There's also a For Her variant. ResMed publishes a sizing guide with cut-outs for each size — print it at 100% scale, with no page scaling, and measure with a relaxed face.
The N30i has four cushion sizes — Small, Medium, Small Wide and Wide — and two frame sizes, standard and small. ResMed suggests starting with the small frame for female patients and the standard frame for male patients, then adjusting: move up a frame size if the frame sits too close to your eyes, and down a size if it sits too close to your ears.
The N30i starter pack includes Small, Medium and Small Wide cushions, so you can try them on the same night and keep the one that seals best. "Wide" refers to width, not length — so a Small Wide isn't the same as a Small.
The size is printed on the cushion and, for the N30i, the frame. Order the same unless you've noticed marks or leaks — in which case re-measure first. Our guide on giving a new mask a fair trial, in the full face mask guide, applies to nasal masks too: judge it on week two, not night one.
Parts and upkeep.
The mask is a one-off. The cushion, headgear and frame are what you'll replace for years.
| Part | Typical replacement | AirFit N20 | AirFit N30i |
|---|---|---|---|
| Cushion | Every 1–3 months | N20 cushion | N30i cushion |
| Headgear | Around every 6 months | N20 headgear | N30i / P30i headgear |
| Frame | Every 6–12 months, or if cracked | N20 frame | N30i frame |
| Elbow | Every 6–12 months, or if stiff | N20 kit with elbow and short tube | 30-series swivel elbow |
Looking after a nasal mask
Wash the cushion daily in warm water with a mild, unscented soap, rubbing the sealing edge gently between your fingers to lift facial oils, then rinse thoroughly and air dry out of direct sunlight. Small nasal cushions are especially sensitive to oils, because the seal sits right at the nostrils.
Wash the headgear weekly by hand and dry it flat. Don't wring it.
Wash your face before bed, and save moisturiser for the morning — night creams make cushions slippery and shorten their life.
Our cleaning guide and replacement schedule cover everything in detail.
Switching from full face to nasal: your first week.
Most people who move to a nasal mask love the lighter feel. A few predictable things catch them out in the first few nights — here's how to get past them.
If you've used a full face mask for a while, your mouth may have got used to falling open. As you drift off, rest your tongue against the roof of your mouth and keep your lips together. If you feel air rushing out of your mouth, that's the signal — close it and the pressure settles.
A dry mouth in the morning is the clearest sign your mouth is opening in sleep. One dry morning isn't conclusive; three in a row is worth acting on. A chin strap trial is the cheapest test, and turning your humidity up a step can ease the symptom while you find out.
Compare your leak figure with the weeks on your old mask. If it's similar or lower and your usage is holding up, the nasal mask is working. If leak has jumped and stayed high every night, either the fit needs attention or air is escaping through your mouth. Our guide to reading your CPAP data explains the patterns.
Don't get rid of it. It's your fallback if the switch doesn't work out, and your backup for nights when a cold or hay fever blocks your nose. Many people end up using both: nasal most nights, full face when congested.
If your full face mask was prescribed or supplied by your sleep service, let them know you're trying a nasal mask. They can check how the change is affecting your therapy, and they may already know whether your breathing pattern suits it.
Five things people believe about nasal masks.
Quick answers on nasal masks.
What is the difference between the AirFit N20 and N30i?
The AirFit N20 is a nasal mask with an InfinitySeal cushion that covers the nose and a short tube at the front, held with magnetic clips. The AirFit N30i is a nasal cradle mask: a small cushion sits under the nose and the tube connects on top of your head, leaving the nose bridge clear. The N20 suits people who want a forgiving, stable seal; the N30i suits restless sleepers and people with marks on the nose bridge.
Can I use a nasal CPAP mask if I breathe through my mouth?
Occasional mouth breathers often manage, sometimes with a chin strap. If you wake with a dry mouth most mornings, air is likely escaping through your mouth and a full face mask may suit you better. Ask your sleep clinic for advice.
Is the AirFit N30i good for side sleepers?
Yes. Its tube connects on top of the head, so there's no hose at the front to pull the mask when you turn, and ResMed says therapy continues when you lie on your side, with airflow compensated through the other side of the frame.
Does the AirFit N20 have magnets?
Yes. The AirFit N20 uses magnetic EasyClick headgear clips, and ResMed warns the magnets may interfere with certain implants or medical devices. If you or anyone sharing your bed has an implanted device, speak to your doctor and device manufacturer first.
What sizes does the AirFit N30i come in?
The AirFit N30i has four cushion sizes — Small, Medium, Small Wide and Wide — and two frame sizes, standard and small. The starter pack includes Small, Medium and Small Wide cushions so you can find the one that seals best.
Why does my nasal mask cause a dry mouth?
Usually because your mouth falls open in sleep, letting the air pushed in through your nose escape through your mouth. Rule out a mask leak first, raise your humidity, and try a chin strap. If that doesn't help, a full face mask may be the better choice.
How often should I replace a nasal mask cushion?
Typically every one to three months, or sooner if it becomes soft, sticky, cloudy or starts to leak. Headgear lasts around six months, and frames six to twelve months.
More UK-specific CPAP guidance.
This guide is general information, not medical advice. Mask suitability depends on your face, your breathing and your prescribed therapy. Speak to your sleep clinic before changing mask type, follow the user guide supplied with your mask, and never adjust your prescribed pressure settings yourself.
The AirFit N20 contains magnets in its headgear clips, which may interfere with implanted medical devices and metallic implants. If you or anyone sharing your bed has one, consult your doctor and device manufacturer before use, and check the safety information supplied with any mask. See your GP or clinic if skin under your mask breaks or blisters, if your nose is blocked most nights, or if dry mouth persists despite these steps.
AirFit™, AirTouch™, InfinitySeal™ and ResMed™ are trademarks of ResMed Ltd. Product features and study figures described are taken from the manufacturer's published information at the time of writing.
