Positive air pressure therapy, or PAP therapy, is a process for pressurizing and delivering airflow to individuals who have a hard time breathing on their own. PAP therapy may be delivered through continuous positive air pressure, or CPAP, provides airflow at a fixed pressure rate; or bi-level positive air pressure, or BiPAP, delivers airflow at a variable pressure rate based on the user’s breathing patterns.
PAP therapy can be a highly effective treatment for people with sleep apnea. While CPAP is normally prescribed for people with obstructive sleep apnea (OSA), BiPAP works best for people with central sleep apnea (CSA). This BiPAP machine guide will include buying considerations, our top picks for BiPAP brands and models, and some additional strategies for sleepers with CSA. First, let’s look at how BiPAP machines work.
What Does a BiPAP Machine Do?
BiPAP machines are considered the most effective treatment for CSA because they apply variable pressure to the airway. Central sleep apnea (CSA) occurs when the brain is unable to send proper signals to muscles that control breathing; unlike obstructive sleep apnea (OSA), there is no physical obstruction associated with CSA. People with CSA experience shallow breathing episodes that last 20 to 40 seconds, and may experience more than 100 per night.
BiPAP machines are considered the most effective treatment for CSA because they apply variable pressure to the airway. People with OSA may also be prescribed BiPAP therapy if CPAP machines are ineffective. The table below illustrates the main differences between CPAP and BiPAP machines.
Type of Apnea Targeted
Continuous positive air pressure (CPAP)
Obstructive sleep apnea (OSA)
Pressure increases until it reaches prescribed rate
$200 to $800
Bi-level positive air pressure (BiPAP)
Central sleep apnea (CSA)
Pressure increases or decreases at variable rates, depending on the user’s breathing
$800 to $1,700
Standard BiPAP machines feature the following components:
Airflow generator: The generator is encased in a small box with a motorized fan. The generator will draw in air from the room, pressurize it, and deliver the modified air to the user via the face mask.
Connective hose: This component connects the generator to the mask. Most hoses measure six feet in length or longer.
Humidifier: BiPAP machines may feature a built-in or detachable humidifier. The humidifier warms water that used to humidify the air before it is delivered to the user via the face mask.
Filter: Filters prevent dust and other allergens from contaminating the air. BiPAP machines feature a removable air intake filter that can usually be cleaned or replaced as needed.
The mask is usually sold separately from the BiPAP machine. Masks are sold in different shapes and styles to accommodate different fit preferences. Any style of mask can be used with a modern BiPAP machine as long as the connective hose is compatible to both. Four general types of mask are available:
Full face: This mask fits snugly around the nose and mouth, and is suitable for those who sleep with their mouths open.
Nasal: This smaller mask fits snugly over the nose, but not the mouth. Nasal masks are ideal for individuals who breathe through their nose while they sleep.
Nasal cradle: These masks fit beneath the nose, delivering oxygen to both nostrils without covering the bridge.
Nasal pillow: A nasal pillow mask forms a seal around each nostril without coming into contact with the bridge of the nose or the mouth.
To operate a BiPAP machine, follow this seven-step process.
Set the machine on a steady surface where it won’t fall or shift positions during the night.
Plug the machine into an AC or DC outlet.
If the humidifier is detachable, insert the chamber filled with distilled water; if the humidifier is built-in, pour water into the chamber.
Attach the connective hose to the generator and the face mask.
Put on the mask and adjust it as needed.
Turn on the BiPAP machine.
Adjust settings as needed throughout the night.
The output of a BiPAP machine is measured in centimeters of water (or cmH20). Most sleep apnea patients require an airflow of at least 6 to 14 cm420, and BiPAP machines usually deliver between 4 and 25 cmH20. To determine how much is needed, apnea patients will typically undergo a sleep study before a BiPAP machine is prescribed to them. All BiPAP machines require a prescription.
Pros and Cons of Using a BiPAP Machine
Benefits of using a BiPAP machine for central sleep apnea include the following:
Effective treatment: BiPAP machines will not cure CSA — there is no cure for sleep apnea at this time — but BiPAP devices are considered the most effective treatment method for people with this condition.
Easy to use: Even with newer and more advanced models, BiPAP machines are usually user-friendly and simple to operate.
Light and portable: BiPAP machines weigh less than seven pounds, and will easily fit into a suitcase or carry-on for convenient travel use.
Wide availability: A wide range of BiPAP machines are available, from simple low-cost devices to more state-of-the-art machines with higher price-points.
Downsides of using a BiPAP machine may include the following:
Noise potential: BiPAP machines are usually quite loud and may cause sleep disruption for the user, as well as his/her sleep partner and anyone sleeping in an adjoining room. Some newer models are designed with quieter motors, but all BiPAP machines carry some noise potential.
Physical discomfort: Issues associated with PAP masks include stuffy noses and irritated eyes.
Restricted sleep mobility: Because the mask is connected to the generator with a hose, some people — including those who toss and turn — find BiPAP machines too restrictive for sleeping.
High cost: BiPAP machines are considerably more expensive than CPAP models. The average model costs at least $800 to $1,000.
Considerations for BiPAP Machine Shoppers
Type of sleep apnea: Although BiPAP machines are normally prescribed for central sleep apnea, they may serve as a last resort for individuals with obstructive sleep apnea who have not responded to CPAP therapy.
Price: BiPAP machines tend to be more expensive than CPAP models. The average BiPAP machine costs between $800 and $1,600.
Size and weight: BiPAP machines are all relatively compact, but available bedroom space may be a consideration for some shoppers. Lighter machines are also more travel-friendly. Most BiPAP machines come with a carrying case for easier transport.
Operating pressure range: Apnea patients usually require airflow that falls between 6 and 14 cmH20, and most BiPAP machines deliver between 4 and 25 cmH20 of airflow. Purchasers should double-check the operating pressure range to ensure the machine will meet their individual pressure needs.
Ramp time: ‘Ramp time’ is the amount of time needed to reach the prescribed operating pressure after the PAP machine is turned on. Ramp time for most BiPAP machines typically falls within 10 to 40 minutes. Alternatively, BiPAP machines equipped with ‘smart ramp’ technology will automatically increase or decrease pressure based on the user’s breathing; these models may not have a set ramp time.
Humidifier: A BiPAP machine may have a built-in humidifier, into which the user must pour water directly, or a detachable humidifier that can be brought to the sink. Generally, humidifiers with higher capacities will perform longer than those with lower capacities.
Sound volume: BiPAP machines always produce some noise, but certain models are quieter than others. Volume for BiPAP machines is measured in a-weight decibels, or dbAs, which express the loudness of air-based sounds.
Hose length: Most connective hoses that link PAP machines to face masks measure at least six feet in length, but users with limited space availability or outlet access may want a hose that extends further.
Power Source: Most BiPAP machines operate on a voltage range of 100 to 240V alternating current (AC), and may also operate using direct current (DC). Power input requirements are always included in the product specs.
Operating altitude: BiPAP machines are only designed to work at certain altitudes; exceeding this elevation will compromise how the air is pressurized and delivered.
Automatic controls: In addition to automatic on and off controls, some BiPAP machines will adjust to the user’s shifting breathing patterns and/or changes in altitude.
Alerts: Some BiPAP machines will alert users if the pressure is turned off, if the mask falls off, or if a leak occurs in the hose. Alerts may be delivered with an alarm and/or LCD backlighting
Sleep data: Most BiPAP machines sold today are equipped with smart technology that monitors sleep patterns in users and provides data readouts. This data may include how much pressure (in cmH20) is delivered on a nightly basis, how long the machine was used (in hours and minutes), and how many days the owner uses the machine per week or month.
Warranty: Most BiPAP machines come with warranties that cover the product for two to five years.
Best BiPAP Machines: Brands and Models
Next, let’s look at the top-ranked BiPAP machines as rated by customers and owners. All customer ratings are generated from authentic user experiences.
ReSmart BPAP 25A
PR System One REMStar 60 Series
AirCurve 10 S
Dimensions (machine and humidifier)
12.3L” x 7.6W” x 4.4H”
6.4L” x 6.5W” x 8.4H”
11.7L” x 7.6W” x 3.3H”
10.8L” x 6.5W” x 4H”
10L” x 4.5W” x 5.9H”
Operating pressure range
4 to 25 cmH20
3 to 25 cmH20
4 to 25 cmH20
4 to 25 cmH20
4 to 25 cmH20
0 to 10 minutes
0 to 45 minutes
0 to 20 minutes
Less than 30 dbA
AC/DC Power voltage range
100 to 240V AC
100 to 240V AC 12V DC
100 to 240V AC
100 to 240V AC 12V DC
100 to 240V AC
Operating altitude (est.)
Alarm and LCD
Carrying case included?
Tuck Customer Satisfaction Rating
89% (26 customer reviews)
95% (18 customer reviews)
94% (22 customer reviews)
98% (31 customer reviews)
98% (17 customer reviews)
Additional Accessories and Sleep Strategies for People with Sleep Apnea
If a BiPAP machine does not treat a patient’s central sleep apnea or proves insufficient, people with CSA may be able to reduce their nighttime sleep disruption through the following means.
Non-mask devices: BiPAP machines may not be a suitable CSA treatment method due to factors like sound volume, size, or price-point. If this is the case, people with CSA may wish to use simpler PAP therapy devices. One possible solution is Provent, a sleep apnea treatment device developed by researchers at Stanford University. Provent features two small, disposable devices with air filters that fit into both nostrils. Provent does not feature a generator or connective hose. This device has been approved by the FDA, and is clinically proven to reduce the symptoms of sleep apnea.
Individuals who are interested in Provent or other alternative sleep apnea treatments should consult their doctor for more information.
Optimal pillow loft: People with sleep apnea often snore more when they sleep on their backs with their heads elevated. For this reason, doctors often encourage people with sleep apnea to sleep on their side, which provides better air circulation and reduces the risk of snoring. However, some people simply cannot sleep in this position — and for these individuals, optimizing the ‘loft’ (or thickness) of their pillow may be a suitable alternative.
‘High-loft’ pillows are thicker than five inches (5″), ‘medium-loft’ pillows are three to five inches (3″ to 5″) thick, and low-loft pillows are thinner than three inches (3″). When pinpointing the best pillow loft, it’s important to keep the following factors in mind:
Head size: People with larger heads tend to prefer high-loft pillows because they provide adequate cushioning and support. Those with smaller heads, on the other hand, often feel more comfortable on medium- or low-loft pillows.
Body weight: Heavier people usually prefer lower-loft pillows because their bodies sink more deeply into the mattress, and thus require less space between the sleep surface and their head. Lighter people may feel more comfortable on higher-loft pillows because they do not sink as deeply.
Shoulder length: People with broader shoulders may require higher-loft pillows because there is more space between their head and the mattress, while those with relatively narrow shoulders typically prefer lower-loft pillows because there is less space.
Mattress firmness: Low-loft pillows work most effectively on softer mattresses because they create less of a barrier between the sleeper’s head and the bed surface; high-loft pillows offer more cushioning and support for firmer mattresses.
The table below provides a detailed breakdown of the three general pillow loft categories.
Adjustable Bed: Adjustable beds enable sleepers to customize the angle of their sleep surface by inclining or declining the head; some models offer adjustable feet, as well. Inclining the head at certain angles can help cut down on snoring for people with CSA. Some adjustable beds also come equipped with ‘anti-snore’ presets that automatically adjust the head of the bed to these angles. Depending on the model, an adjustable bed may have manual, remote, or app-based controls.
Most adjustable beds support at least 600 pounds — and some models support as much as 800 pounds. This makes them suitable for most adults and their sleep partners. Adjustable beds normally cost at least $1,000, and some are priced at $3,000 or higher. For more information, please visit our Adjustable Bed Reviews page.
For more information on sleep apnea and potential treatment methods, please visit the following Tuck.com pages: