CPAP vs APAP vs BiPAP Machines: Compared

Introduction

If you have just been diagnosed with sleep apnea, or you are researching a replacement machine, you will quickly run into three acronyms: CPAP, APAP, and BiPAP. They all deliver pressurised air to keep your airway open during sleep, and they all use the same masks and tubing. What separates them is how that pressure is delivered — one fixed level, an automatically adjusting range, or two distinct levels for breathing in and out.

This guide explains the difference in plain language so you can understand what your prescription means and what to expect from each type of machine. CPAP Machines Canada stocks all three categories: CPAP machines, Auto CPAP (APAP) machines, and BiPAP machines. Importantly, which one is appropriate for you is a clinical decision — all three require a prescription, and the type and settings must be determined by your prescribing physician or sleep specialist.

Quick Comparison Overview

The table below summarizes how the three machine types differ in the way they deliver therapy.

All three types work with the same mask styles — nasal, nasal pillow, and full face — so changing machine type does not usually mean changing the mask you are used to.

How Each Type Works

CPAP — one steady pressure

A CPAP machine delivers a single, constant pressure that stays the same from the moment therapy starts until you take the mask off. Your clinician determines that one number, usually from a sleep study or a titration period. Because the pressure never changes, CPAP is the simplest of the three to set up and generally the most affordable. The trade-off is that the pressure is calibrated to cover your worst-case need, so you receive that same level even during parts of the night when less would be sufficient.

APAP — a pressure range that adapts

An APAP machine, usually sold as an "Auto CPAP" or "AutoSet", is prescribed with a minimum and a maximum pressure rather than a single value. The device monitors your breathing and moves within that range throughout the night, increasing when it detects airway narrowing and easing off when you do not need as much. Because pressure needs genuinely do vary — with sleep position, sleep stage, alcohol, congestion, and weight changes — APAP often results in a lower average pressure across the night. Most modern home machines sold today are auto-adjusting, including the models covered in our AirSense 11 vs DreamStation 2 comparison.

BiPAP — two separate pressures

A BiPAP (bilevel) machine uses two distinct pressures: a higher one when you breathe in (IPAP) and a lower one when you breathe out (EPAP). The machine senses your breathing cycle and switches between them. Because the drop on exhalation is a prescribed setting rather than a comfort feature, bilevel therapy can be considerably easier to exhale against — which is why it is often considered when someone requires high pressures or has not tolerated CPAP or APAP. Bilevel devices are also used for certain conditions beyond straightforward obstructive sleep apnea, which is one reason the prescribing decision sits firmly with your clinician.

Comfort, Cost, and Daily Use

On exhale comfort, all three approaches address the sensation of breathing out against incoming air, but in different ways. CPAP and APAP machines typically include a pressure-relief feature that eases pressure slightly during exhalation. BiPAP builds the difference into the prescription itself, with a separately set exhale pressure that is usually a larger drop than a comfort feature provides.

On data and apps, the machine type does not determine the quality of reporting — the specific model does. Current home machines across all three categories record compliance and therapy data, and most connect to a smartphone app so you and your care team can review progress.

On cost, CPAP is generally the most affordable, APAP sits in the middle, and BiPAP is typically the most expensive, reflecting the added complexity of bilevel delivery. Many Canadian extended health plans cover part of the cost of a prescribed machine; current pricing for each category is listed on the collection pages, and our team can help you with the paperwork for a reimbursement claim.

Which Type Is Usually Prescribed for Whom

The most important point in this whole guide: you do not choose between CPAP, APAP, and BiPAP yourself. The machine type and its settings come from your prescription. The summaries below describe the general clinical reasoning so you understand what your prescription means — not so you can self-select.

A CPAP machine may be prescribed when:

• A sleep study has established a single effective pressure that works consistently
• Pressure requirements are stable through the night and across positions
• A straightforward, lower-cost device meets the clinical need

An APAP machine may be prescribed when:

• Pressure needs vary through the night, by sleep position, or over time
• A single fixed pressure has felt higher than necessary for much of the night
• The prescriber wants a pressure range rather than a single titrated value

A BiPAP machine may be prescribed when:

• Higher therapy pressures are required and exhaling against them is difficult
• CPAP or APAP therapy has not been tolerated despite comfort adjustments
• The clinical picture calls for separately controlled inhale and exhale pressures

Frequently Asked Questions