Monoplace vs Multiplace Hyperbaric Chambers: The Complete Comparison

Monoplace & multiplace chambers are the two core hyperbaric vessel types, and size is seldom the real dealbreaker between them. Their core differences lie in the pressurization strategy of each vessel and, consequently, in who inhales the pure oxygen. Monoplace chambers inflate the entire sealed vessel with oxygen-close to 100% pure, so that the lone patient breathes it in directly.

Multiplace chambers use air to pressurize a steel room; patients don on masks or hoods to receive a supply of oxygen while an attendant oversees them within the chamber. Everything else, including equipment expenses, staffing needs, fire controls, and patient suitability, is a function of that fundamental design distinction.

Monoplace vs Multiplace at a Glance

A monoplace chamber is designed for the treatment of a single patient in a tube pressurized by oxygen, where the patient is breathing the chamber atmosphere. Multiplace units treat multiple patients simultaneously in a room pressurized by air, where they all breathe oxygen by means of masks or hoods, with working pressure in both formats measured in atmospheres absolute (ATA). Sorting out the shell question first is the fastest way to tell whether you are actually weighing a hard or soft hyperbaric unit.

These figures are the MACY-PAN estimate at the time this publication was released and may fluctuate according to configuration and options.

What Is a Monoplace Hyperbaric Chamber?

Defined simply, a monoplace hyperbaric chamber is a pressure vessel used to treat a single patient.

This vessel is typically filled with near 100% oxygen, so the patient can inhale it directly, as a mask is not needed. They typically take the form of clear, cylindrical acrylic tubes.

According to the U.S. FDA approvals, these monoplace systems can provide oxygen pressures that exceed atmospheric pressure by as much as 3ATA (equivalent to about 30 psi); many commercially available units offer treatments up to this ceiling, although the operating pressures of some systems will vary.

Because the patient lies supine on a padded tray within a transparent tube, he or she can maintain visual contact with the outside world, communicate with technicians via an intercom system, and forgo the mask, which keeps each session simple.

This operational simplicity makes the monoplace hyperbaric system ideal for the outpatient clinic and medical practice setting, where only one technician may be needed to run multiple treatments, and the chamber can readily fit into an existing room. One downside is that there’s no provision for clinicians to physically reach patients during their sessions.

Picture a busy wound-care clinic running back-to-back diabetic-foot wound healing sessions: a single technician can load one patient, start the treatment, and prep the next appointment while the first runs, because the low staffing model is the whole point. That efficiency is exactly why “hyperbaric chamber staffing” is a smaller line item for a monoplace program than for a multiplace one. The pain point shows up only when a patient becomes unstable mid-session, since no attendant is inside to intervene.

One clarification: while a single, fully sealed and pressurizing tank filled with pure oxygen (oxygen-fill) is the standard in monoplace chambers, this arrangement isn’t immutable. Some monoplace designs can operate at higher air pressure while simultaneously delivering a mask or built-in hood filled with pure oxygen-which works much like the multiplace setup. It’s a pattern found more commonly in hard-shell monoplace designs and influences some of the considerations and trade-offs in cost, staffing and safety detailed later in this article, but “monoplace” refers to capacity, not configuration.

What Is a Multiplace Hyperbaric Chamber?

A multiplace hyperbaric chamber is a walk-in, room-size steel cylinder that holds two or more patients and is filled with ordinary air. Because it is walk-in, ambulatory patients can step inside on foot while an unstable patient is wheeled in on a gurney. Oxygen is delivered to each patient, who wears an individually sealed mask or hood, or-for patients on a ventilator-an endotracheal circuit.

Inside the chamber, a qualified person known as an attendant (or tender) monitors and assists the patients, offering hands-on treatment. “A chamber for two or more people is called a multiplace chamber,” says Mayo Clinic, and the oxygen is provided individually to everyone in the chamber.

Inside-attendant access is what makes the multiplace format a critical care tool: consider a hospital intensive care unit treating a ventilated patient with a gas embolism, where the tender manages the endotracheal circuit, adjusts intravenous lines, and responds to alarms without breaking pressure. That hands-on capability sits at the core of the mono vs multi trade-off, and it is why hospitals accept the higher footprint and staffing cost. This pain point is the reverse of a monoplace clinic’s: every session ties up an operator plus a trained attendant inside the vessel.

These chambers can accommodate anywhere from two individuals to more than 20 patients in large hospital settings. Multiplace units are used in dive medicine and research hospitals and provide the same basic technology-a sealed steel cylinder pressurized to a higher level than ambient-as MACY-PAN’s hard-shell medical chambers.

The Core Difference: How Each Chamber Is Pressurized

At its root, the fundamental difference between the two kinds of chambers is the following: in a monoplace, the entire vessel is pressurized with oxygen, so the patient is effectively receiving it directly. This is The Oxygen-Source Divide. A multiplace chamber instead raises ambient pressure using ordinary air and delivers oxygen through an attached mask, meaning the effective seal of that mask determines how much pure oxygen actually reaches the patient’s bloodstream.

Why is that clinically important? Adding pressure is useless unless it’s putting additional oxygen into the patient’s bloodstream. At 1 atm and breathing room air, the typical partial pressure of oxygen in arterial blood is 157 mm Hg. Add pressure and a pure oxygen breathing gas, and the value jumps quickly. In studies of hyperoxia, breathing 100% O2 at about 1.5 ATA pushes the alveolar oxygen pressure to roughly 1,053 mmHg-considerably higher than the level achieved by simply breathing pure oxygen at sea level, which reaches about 663 mmHg. Cannellotto et al., 2024

First-party oxygen delivery. Try it for your own protocol: at 2.4 atm, the monoplace patient hits the 1,053 mm Hg mark simply because the chamber environment *is* the 100% O2 breathing mix. However, for the multiplace patient to reach the same 1,053 mm Hg alveolar PO2 at 2.4 atm, a perfect seal around his or her mask or hood must be achieved. Any leaky mask at that pressure could result in an arterial PO2 that’s significantly lower than the one in a monoplace patient.

Capacity, Attendant Access, and Clinical Use Cases

Match the technology to the clinical need, not to perceived prestige. According to one peer-reviewed comparison of monoplace and multiplace chambers, small acrylic monoplaces are “less staffing intensive and require no in-chamber attendant,” whereas “the multiplace chamber is more appropriate for treatment of the critically ill.” Lind, 2015

Can a Monoplace Chamber Treat Critically Ill Patients?

Here’s where the assumption is faulty: many buyers think all critically ill patients require a multiplace chamber. In fact, it’s not always the case. Clinicians will treat ventilated and unstable patients in monoplace chambers with the use of special hyperbaric-rated ventilators and IVs – sometimes even positioning or wheeling the chamber directly into the ICU to accomplish this.

“In fact, a monoplace is moved to the ICU to accommodate such patients,” notes Wound Education Partners.

Moreover, with regard to decompression illness, a monoplace chamber may even be safer because “it provides victims immediate access to recompression in settings where traditional multiplace chambers aren’t available.” Clarke, 2020.

The true line: Critical patients in a monoplace program require the appropriate ventilator, qualified staff, and a well-thought-out set of protocols.

Otherwise, access to hands-on treatment really is compromised, and a multiplace chamber is the tidier choice.

Safety and Fire Risk Compared

One isn’t necessarily safer than the other, intrinsically; they address different hazards.

Inside a monoplace, the 100 percent oxygen environment necessitates rigorous exclusion of ignition sources and non-approved materials. Because it contains air, a multiplace confines the 100 percent oxygen risk to the breathing circuit (rather than the entire room), but introduces the danger of people pressurized alongside equipment, requiring hands-on emergency procedures.

This is where the mono vs multi hyperbaric decision meets real bedside risk. A team choosing a hyperbaric chamber for critical care has to weigh two opposite failure modes: in a monoplace, a fire risk is contained but a deteriorating patient cannot be reached; in a multiplace, staff can act immediately, yet more people share the pressurized space. As a concrete example, if a ventilated patient dislodges a line at 2.4 ATA, a multiplace tender fixes it in seconds, while a monoplace program must decompress first. That single scenario, more than any spec sheet, is what pushes acute hospitals toward multiplace. Both formats share the same core clinical contraindications, so this decision is really about bedside access, not about which patients qualify for therapy.

Cost and Investment: Sizing the Mono-to-Multi Capital Gap

The two chamber types differ greatly in price, and that cost isn’t directly proportionate to your patient volume. A single 2.0 ATA hard monoplace sits around $47,995 as a retail reference, while a 2.0 ATA multiplace runs about $129,000 – roughly 2.7 times more. A factory-direct MACY-PAN HE5000 multiplace has been reseller-listed near $65,100, which shows how much of a retail figure is markup.

Besides the sticker price, multiplace chambers also carry higher operating expenses, requiring both an on-site attendant and an operator per session, and their session length often runs longer once the compression and decompression of a larger vessel are counted (a monoplace needs just one operator per session).

And purchase price only accounts for half the picture; a center’s reimbursement landscape and treatment indications can often be more important to return on investment than the chamber’s cost alone, determining how many payable sessions are actually delivered. For a price guide across various chamber types, visit our guide to the cost of hyperbaric chambers. To explore by pressure rating, consult our hyperbaric chamber by ATA pressure table.

Standards, Certification, and Facility Requirements

Both types of chambers are pressurized human occupancy devices. Any medical grade vessel sold in the US must be FDA cleared under 510(k) Class II and built to the ANSI/ASME PVHO-1 (Pressure Vessels for Human Occupancy) safety standard, the same one referenced by NFPA 99. MACY-PAN chambers also come ISO 13485 and ISO 9001 certified with the CE Mark, with SGS tested 304 Stainless steel.

Facility-wise is where multiplace gets difficult. Most multiplace suites require 800-1,200 square feet, an oxygen supply of 10-15 LPM, and a package consisting of chamber plus concentrator plus compressor plus intercom, all built according to NFPA 99 code. Monoplace units fit into an existing clinical room with little site preparation.

Which Should You Choose? The 5-Question Mono-vs-Multi Router

Take your situation through these five questions in order. Whichever is the first to produce a “multiplace” response is most likely your answer; if you don’t hit any of them, the less expensive monoplace is generally the quicker, lower-risk solution for most outpatient clinics.

Outpatient clinics, wellness center, and one location practices often drop out at question 1 or 4 and hit monoplace (a portable or compact hard chamber). Hospitals and dive-medicine programs frequently go to question five and already have a definite multiplace need. If you haven’t already settled the issue of shell types as a whole, our soft vs hard chamber guide covers the underlying pressure question.

Walk a real case through it. A three-provider podiatry clinic treating diabetic-foot wounds answers “no” to questions one through three (one patient at a time, no ventilated patients, no dive emergencies), then hits question four: its capital budget is under $60,000. It stops there and buys a single 2.0 ATA monoplace near the $47,995 reference, avoiding the roughly $129,000 a multiplace would demand. A regional trauma center answers “yes” at question two, because it must treat ventilated carbon-monoxide and gas-embolism patients with an attendant inside, and commits to the 800–1,200 sq ft build. Same five questions, opposite outcome — and neither facility overspends on capacity it will not use.

“Small cost-efficient and easy-to-install acrylic monoplace chambers require less staffing and no inside attendant. The multiplace chamber is better suited for HBOT of critically ill patients.”

F. Lind, Undersea & Hyperbaric Medicine Society (UHMS) review, 2015

Industry Outlook: What Is Changing in Hyperbaric Equipment

The best thing a buyer can do is understand where the demand is concentrated – not headline growth rate. Monoplace units accounted for an estimated 58% of the hyperbaric device market in 2024, according to Strategic Market Research. This represents widespread usage in outpatient wound-care centers and ambulatory care centers. “Simply put, growth is occurring in locations that best suit monoplace and portable units, while multi-patient remain confined to hospital and diving medical environments.

Budget according to your patient flow.”

Two concrete trends to anticipate are as follows: The regulatory standard for multi-unit facilities is increasing; primary and secondary fire-suppression is now a requirement under the latest 2024 NFPA 99 code. Beyond that, hyperbaric equipment overall has an average market growth of 5.5-10.7 percent according to market research; while the figure is broad, it highlights continuing equipment needs.

Frequently Asked Questions

Verified by MACY-PAN (Shanghai Baobang Medical Equipment) technical department. The quoted prices and technical parameters are reference values and will differ based on the product configuration. Please confirm the final details before placing an order.