Sleep Apnea Machines: Types, Features & How to Choose

A sleep apnea machine is a positive airway pressure (PAP) device. It blows gently pressurized air through a tube and mask to keep your airway open while you sleep [2][3]. Most people with obstructive sleep apnea use a CPAP or auto-adjusting CPAP (APAP), and in the US these machines need a prescription [1][8][9].

Your clinician picks the machine type and pressure. Your choices are mostly about comfort: humidification, noise, size, data, and above all the mask.

Below: how the machines work, the main types, the specs worth comparing, and what your machine records.

Key takeaways

Your clinician chooses the type (CPAP, APAP, BiPAP or ASV) and the pressure. You choose comfort features, size and, above all, a mask that seals.
For most adults with obstructive sleep apnea, CPAP or APAP is recommended over bilevel for routine treatment.
Modern machines log usage, leak, pressure and events. Insurers and clinicians use that data, and you can too.

How does a CPAP machine work?

A CPAP machine takes in room air, filters it, and pressurizes it. It then sends that air through a hose into your mask [3]. The steady pressure acts like an air splint. It stops the tongue, uvula, and soft palate from collapsing into the airway during sleep [3].

Labelled diagram of a PAP setup: blower and filter inside the machine, heated humidifier, heated tube, and mask with headgear — Figure 1. The parts of a PAP setup: blower, filter, humidifier, tube and mask [2][3].

The basic parts are simple [2][3]:

A motor (blower) that creates the air pressure.
An air filter that keeps dust out of the machine.
A hose (tube) that carries air to your face.
A mask and headgear over the nose, under the nose, or over the nose and mouth.
A heated humidifier on most modern models, which adds moisture to the air.

Pressure is measured in centimeters of water (cm H2O). The four machines we compare below all run between 4 and 20 cm H2O [9][11][12][14]. Your clinician sets your pressure or pressure range. Never change it yourself. Our guide to CPAP pressure settings explains what the numbers mean.

What are the types of sleep apnea machines?

There are four main types. They differ in how they deliver pressure, which decides who each is for.

Four pressure-over-time lines: CPAP flat, APAP varying within a range, BiPAP with a higher level on inhale and lower on exhale, ASV with varying support — Figure 2. How pressure behaves over a night with each type of machine (simplified) [3][4][5].

Type	How pressure works	Typically prescribed for
CPAP (fixed)	One steady pressure, breathing in and out [4]	Obstructive sleep apnea (OSA) [1]
APAP / Auto CPAP	Adjusts automatically within a range your clinician sets [3]	OSA; also used to start therapy at home [1]
BiPAP / Bilevel	A higher pressure when you breathe in (IPAP) and a lower one when you breathe out (EPAP) [4]	People who need two pressures, such as some with COPD, heart failure, high carbon dioxide, or central apnea [4]
ASV (adaptive servo-ventilation)	Senses your breathing and adds support when it detects pauses or slow breathing [5]	Central sleep apnea or "complex" sleep apnea [5]

CPAP vs APAP: which is used for obstructive sleep apnea?

For most adults with OSA, the choice is between fixed CPAP and APAP. The American Academy of Sleep Medicine (AASM) 2019 guideline recommends either CPAP or APAP for ongoing treatment of OSA [1].

The same guideline recommends starting therapy with either APAP at home or an in-lab titration study, for adults with no major other conditions [1].

CPAP vs BiPAP: when is bilevel used?

The AASM suggests CPAP or APAP over bilevel (BPAP) for routine OSA treatment [1]. Bilevel is usually saved for specific needs. Those include trouble breathing out against pressure, or conditions where carbon dioxide builds up in the blood [4].

What is an ASV machine?

ASV machines are made for central sleep apnea, where the brain does not send the signal to breathe [5]. ASV is not right for everyone. The AASM recommends against ASV for central sleep apnea linked to heart failure when the ejection fraction is 45% or lower, with moderate or severe central apnea [6]. This is a decision for your sleep and heart specialists.

If you are still unsure where you fit, start with our overview of sleep apnea treatment and talk to your clinician.

What features should you compare on a sleep apnea machine?

Within a given type, most machines do the same core job. The day-to-day differences are comfort and convenience.

Humidifier and heated tube

Dry mouth, a stuffy nose, and nosebleeds are common CPAP side effects. Cleveland Clinic and NHLBI tie these mainly to dry air [2][3]. A heated humidifier helps [3][7]. A heated tube keeps the air warm on the way to your mask and cuts down on condensation, which F&P says its ThermoSmart tube is designed to reduce [14].

Check whether the humidifier is built in or a separate tub, how much water it holds, and whether it has an automatic mode. For example, the AirSense 11 offers manual levels or an automatic Climate Control mode, and the auto mode needs ResMed's heated tube [10].

Ramp

Ramp starts you at a low pressure and slowly rises to your prescribed setting as you fall asleep [7]. Some machines detect sleep onset and only raise pressure after you drift off. ResMed calls this AutoRamp [10]. Philips's Ramp Plus lets you choose the starting pressure [12].

Exhale relief (EPR, Flex, Expiratory Relief)

Exhale relief lowers pressure a little each time you breathe out. ResMed calls it EPR, Philips calls it Flex, and F&P calls it Expiratory Relief [10][12][14]. It is not the same as bilevel therapy.

Noise

Mayo Clinic notes that most new CPAP machines are almost silent [7]. Machines in our table are rated between about 27 and 29 dBA [9][11][14]. If your machine gets louder, Mayo Clinic suggests checking that the air filter is clean and not blocked [7].

Data, apps, and connectivity

Most current machines store therapy data and send it by cellular modem or Bluetooth to an app or your care team. Some also use an SD card or USB stick [9][12][14]. More on why this matters below.

Size and travel

Home machines with humidifiers weigh about 1 to 1.7 kg [9][12][14]. Travel CPAP machines are much smaller. The ResMed AirMini weighs 300 g and uses waterless humidification instead of a water tub [11]. Our guide to travelling with CPAP and your data covers the data trade-off.

Popular sleep apnea machines compared

This table uses only manufacturer-published figures. It is not a ranking. The right machine depends on your prescription, mask, insurance, and supplier. Sound figures come from slightly different test setups, so ignore small gaps.

Machine	Type	Pressure range	Size and weight	Sound level	Humidification	Data and connectivity
ResMed AirSense 11 (AutoSet and fixed CPAP models)	APAP or CPAP [10]	4–20 cm H2O [9]	94.5 × 259.4 × 138.5 mm; 1,130 g with humidifier tub [9]	27 dBA ± 2 with tub, CPAP mode [9]	Integrated heated humidifier; auto mode with heated tube [10]	SD card, cellular, Bluetooth to myAir app [9][10]
Philips DreamStation 2 Auto CPAP Advanced	APAP or CPAP [12]	4–20 cm H2O [12]	256.8 × 158.5 × 84.8 mm; 1,040 g without power supply [12]	Not published on spec sheet	Integrated 325 ml humidifier; optional heated tube [12]	Cell modem, Bluetooth, DreamMapper app [12]
Fisher & Paykel SleepStyle	Auto or fixed CPAP [15]	4–20 cm H2O [14]	144 × 177 × 183 mm; 1.7 kg [14]	28.0 ± 1.5 dBA [14]	Integrated 380 ml humidifier; ThermoSmart heated tube [14]	InfoUSB data stick, Bluetooth, cellular on some models [14][15]
ResMed AirMini (travel)	APAP or CPAP [11]	4–20 cm H2O [11]	133 × 84 × 52 mm; 300 g [11]	29 dBA ± 2, CPAP mode [11]	Waterless HumidX [11]	Bluetooth to AirMini app [11]

US availability notes: Philips Respironics has paused sales of new CPAP and BiPAP machines in the US under a consent decree with the US government. It can still service existing devices and sell masks, parts, and supplies [13]. Fisher & Paykel says it no longer sells the SleepStyle in the US [15]. Both remain in wide use.

Want help narrowing the field? Our machine finder walks you through the questions to bring to your clinician or supplier.

Is the mask as important as the machine?

Often, yes. Mayo Clinic lists the wrong mask size or style as the first common CPAP problem. It also says a leaky mask can dry out your nose and that mouth breathers may do better with a full-face mask or chin strap [7].

Masks come in three main styles: nasal pillows, nasal masks, and full-face masks. Most masks work with most machines. Our Mask Finder and our guide to choosing a CPAP mask can help you shortlist options to try.

Do you need a prescription for a CPAP machine?

Yes, in the United States. CPAP machines are prescription medical devices. The FDA's device database lists the ResMed AirSense 11 as "Prescription Use (Rx): Yes" [8]. Both ResMed and Philips state that US federal law restricts these devices to sale by or on the order of a physician [9][12].

In practice, the path usually looks like this:

You get a sleep apnea test, at home or in a lab.
Your clinician diagnoses the type and severity of your sleep apnea.
They prescribe a machine type and pressure settings.
A durable medical equipment (DME) supplier sets you up with the machine and mask.

NHLBI notes that insurance typically works with a medical device company to supply the machine, mask, and tube [2].

How much does a sleep apnea machine cost, and does insurance cover it?

Prices vary too widely for one number. Cost depends on the model, buying versus renting, your insurance, your supplier, and ongoing supplies like masks, cushions, filters, and tubing.

Medicare basics (US)

Medicare's rules are a useful reference point:

Who qualifies. Medicare covers CPAP for OSA with an AHI of 15 or more, or an AHI of 5 to 14 with certain symptoms or conditions, such as daytime sleepiness, high blood pressure, heart disease, or a history of stroke [18].
A 12-week trial. Medicare may cover an initial 12-week trial of CPAP [16].
Proving you use it. Continued coverage requires use of at least 4 hours per night on 70% of nights during a 30-day stretch in the first three months. An in-person check-in between day 31 and day 91 is also required [17].
Rent to own. Medicare pays the supplier to rent the machine for 13 continuous months. After that, you own it [16].
Your share. After the Part B deductible, you pay 20% of the Medicare-approved amount [16].

That adherence rule is one big reason your machine's usage data matters. Our guide to CPAP usage hours and adherence explains how it is counted.

What does a sleep apnea machine record, and why does it matter?

Modern machines are data loggers. Depending on the model, they record usage hours, mask leak, pressure, and breathing events. Some store detailed flow waveforms too [12][14]. F&P says its InfoUSB stick can hold up to 5 years of summary data on the SleepStyle [14].

The most useful numbers are:

AHI (apnea-hypopnea index). Breathing events per hour while on therapy. See what AHI means.
Usage. Hours per night. This is what insurers check.
Leak. How much air escapes around the mask. High leak can lower comfort and effectiveness. See CPAP leak rate explained.
Pressure. On an auto machine, how high pressure goes during the night.

Your care team often reviews this data. NHLBI notes your provider may check your machine's data card to confirm use and effectiveness [2]. The AASM also suggests telemonitoring-guided support during the early weeks of therapy [1].

A night in Apnealytics showing AHI, usage, leak and pressure — Figure 3. One night in Apnealytics: AHI, usage, leak and pressure.

You can look at it yourself, too. Apnealytics reads the SD card from ResMed machines today, and turns the files into nightly charts of AHI, usage, leak, and pressure. Philips DreamStation 1, Fisher & Paykel SleepStyle and the Luna G3 are in testing (usage, adherence and pressure setting for DreamStation 1), the DreamStation 2 and some other machines are on a waitlist, and the ResMed AirMini has no SD card and syncs over Bluetooth only, so Apnealytics cannot read AirMini data. See which machines work for the current list. Apnealytics is a tracking tool, not a diagnostic device. Bring questions about your numbers to your clinician.

How do you clean and care for a sleep apnea machine?

Follow your machine's user guide first. As an example, ResMed's AirSense 11 guide says to [9]:

Daily: empty the humidifier tub, wipe it, and let it air-dry out of direct sunlight. Refill with distilled water if you use the standard tub.
Weekly: wash the tubing, tub, and outlet connector in warm water with mild dish soap. Rinse and air-dry.
Every six months: replace the air filter, or sooner if it is dirty or damaged.
As needed: replace parts that are cracked, cloudy, torn, or discolored.

Cleveland Clinic and NHLBI recommend cleaning the mask and tube every day [2][3]. The FDA says most CPAP accessories can be cleaned with mild soap and water [19]. It also warns that there are no FDA-cleared devices for cleaning, disinfecting, or sanitizing CPAP machines. That includes ozone and UV gadgets sold for this purpose [19].

So what is the best sleep apnea machine?

There is no single best sleep apnea machine for everyone. The best one is the type your clinician prescribes, paired with a mask that seals well, that you actually use every night. Compare humidification, ramp and exhale relief, noise, size, and data access.

If you are already on therapy, tracking your nightly AHI, leak, and usage is the simplest way to see whether your setup is working. Apnealytics can read your ResMed machine's data card and show those trends in one place. Start free on the pricing page, and keep your clinician in the loop on anything that looks off.

Frequently asked questions

What is a sleep apnea machine called?

The most common sleep apnea machine is called a CPAP machine, short for continuous positive airway pressure. Related machines include APAP (auto CPAP), BiPAP or bilevel, and ASV. All of them are positive airway pressure (PAP) devices. They push pressurized air through a mask to keep your airway open during sleep. Your clinician decides which type fits your diagnosis.

Can you buy a sleep apnea machine over the counter?

Not in the United States. CPAP and related machines are prescription medical devices, and federal law restricts their sale to the order of a physician. You will usually need a sleep test and a diagnosis first. A clinician then prescribes the machine type and pressure. A medical equipment supplier, often working with your insurance, provides it.

What is the difference between CPAP, APAP, and BiPAP?

CPAP delivers one fixed pressure all night. APAP adjusts pressure automatically within a range your clinician sets. BiPAP uses two pressures: a higher one when you breathe in and a lower one when you breathe out. For most adults with obstructive sleep apnea, AASM guidance favors CPAP or APAP over bilevel for routine treatment.

Are sleep apnea machines loud?

Most modern machines are quiet. Manufacturer figures for current models are roughly 27 to 29 decibels, about the level of a soft whisper. Louder noise often comes from a mask leak or a blocked air filter, not the machine itself. Check your mask fit and filter first, then contact your supplier if the noise continues.

Does Medicare cover sleep apnea machines?

Yes, if you meet its criteria. Medicare may cover a 12-week CPAP trial for obstructive sleep apnea. It then requires proof that you use the machine at least 4 hours a night on 70% of nights in a 30-day period. Medicare rents the machine for 13 months, after which you own it. You pay 20% coinsurance after the Part B deductible.

What is the best travel CPAP machine?

There is no single best travel CPAP. Mini machines such as the ResMed AirMini weigh about 300 grams and use waterless humidification. Smaller size brings trade-offs, such as different humidification and fewer data options. Ask your clinician whether a travel machine suits your prescription, and check mask compatibility first.

How long do sleep apnea machines last?

It depends on the model and how well you care for it. Warranties vary; Philips lists 2 years for DreamStation 2. Insurance plans set their own replacement schedules, and Medicare transfers ownership to you after 13 months of rental. Replace filters, tubing, and mask parts on the schedule in your user guide.

Sources

Tagged:Sleep apnea CPAP Machines Insurance

Not medical advice. Apnealytics is a tracking and coaching tool, not a diagnostic device. Machine-estimated numbers are not a clinical diagnosis; talk to your clinician about your therapy.

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