Here we’ll explain the pressures of soft and hard hyperbaric chambers in simple terms, show what each setting feels like by comparing it to how deep you’d be underwater, clear up common misconceptions, and go over safety tips for hyperbaric oxygen therapy.
Why Pressure Matters in Hyperbaric Oxygen Therapy
Pressure is one key factor that makes hyperbaric therapy effective. The other is the amount of oxygen you breathe while at that pressure. As pressure increases, more oxygen is driven into the bloodstream and tissues.
For someone buying a hyperbaric chamber, pressure affects three things you’ll care about:
- How it feels: More pressure can feel more noticeable in your ears.
- What it can do: Some research uses mild pressures, such as 1.3 to 1.5 ATA, while many clinical protocols use 2.0 ATA or higher. Different pressures are studied for various conditions.
- Comfort and frequency: Lower pressures are often easier to tolerate for daily use.
Clinical studies use a range of pressures depending on the condition being studied. For example, sports and wound care research often use hyperbaric pressures of 2.0 ATA and above, while some studies on mild hyperbaric treatment use pressures in the 1.3 to 1.5 ATA range.
What Does ATA Mean?
ATA stands for atmosphere absolute. At sea level, the air pressure is 1.0 ATA. When you go underwater, pressure rises.
Hyperbaric chambers replicate this pressure increase in a soft or hard chamber within a controlled environment, allowing you to breathe ambient air, 100% oxygen, or supplemental oxygen during your session.
A simple rule to remember:
- Every 33 feet of sea water adds about 1.0 ATA.
So the math is easy: Depth (feet) = (ATA − 1.0) × 33.
If you prefer meters, multiply feet by 0.3048.
That gives us nice, relatable comparisons you can picture. For example:
- 1.3 ATA is about 10 feet underwater.
- 2.0 ATA is about 33 feet underwater.
Why Does A Hyperbaric Chamber Say 4.4 PSI But Others Say 1.3 ATA?
Soft hyperbaric chambers are often displayed in pressure in PSI. Hyperbaric guides, studies, and brands usually talk in ATA instead. PSI is just another way of describing the same thing.
A reading of around 4.4 PSI above normal air pressure is the same as 1.3 ATA, so the hyperbaric chamber isn’t stronger or weaker. It’s simply using a different scale.
Another way some manufacturers' hyperbaric gauges can read is in KPA or Kilopascals. So let’s dive into that term also!
What are PSI, ATA, and KPA in Hyperbaric Terms?
All three measure pressure in the same way, just using different units.
The Conversion of PSI To ATA
The conversion is simple once you know the rule:
14.7 PSI = 1.0 ATA at sea level
So you can convert by dividing PSI by 14.7 and then adding the sea-level pressure if needed.
For practical use in hyperbarics:
Most soft chambers use 4.0 to 4.4 PSI, which equals 1.3 ATA. Hard chambers use more PSI because they reach higher ATA settings.
Hyperbaric Pressure Levels Explained: What Each Setting Means, How It Feels, and Who It’s Best For
1.3 ATA Hyperbaric Chambers: mild pressures - known as a soft or mild hyperbaric chamber
- Underwater equivalent: about 10 feet (3.0 meters).
- What it means: A pressure level slightly higher than normal air and generally easy on the ears. These hyperbaric chambers use ambient air drawn from the room, the same oxygen concentration we breathe daily. Many users choose to connect an oxygen concentrator to the chamber to enhance their oxygen intake during sessions.
- How it feels: Mild “pop” or fullness in the ears during pressurization. Many people barely notice it.
- Primary Users: First-time users, people who prefer milder pressure levels, and households with members who want the easiest equalizing.
- FDA Approved: 1.3 ATA is the FDA-approved pressure level in the U.S. for soft hyperbaric chambers. Any FDA-approved hyperbaric chamber requires a doctor’s prescription. Newtowne Hyperbarics is one of our favorite FDA-approved brands, offering an economical option for getting started with hyperbaric oxygen therapy. So if you’re wondering why some chambers require a prescription while others—like our Oxygen Health Systems and Airvida brands do not, here’s the simple answer: FDA-cleared soft chambers at 1.3 ATA require a prescription; non-FDA-cleared wellness chambers do not.
No need for confusion!
- Notes from studies: Recent work has examined short exposures at 1.3 ATA and found measurable physiological signals, which help explain why many people report benefits even at mild pressures.
Newtowne Shoe Chambers Above
1.4 ATA Hyperbaric Chambers: soft or mild hyperbaric chamber
- Underwater equivalent: about 13 feet (4.0 meters).
- What it means: Noticeably more “pressure” than 1.3 but still in the mild range. These hyperbaric chambers rely on ambient room air, which has the same oxygen concentration as the air we breathe daily. Some users pair the chamber with an oxygen concentrator to boost their oxygen intake during sessions.
- How it feels: You will feel more fullness during compression, and you will still need to equalize your ears multiple times when pressurizing and depressurizing.
- Primary Users: People who tried 1.3 and want a touch more substantial effect, or buyers who want mild but not minimal settings. These hyperbaric pressures are not FDA-approved in the USA at this time for the soft hyperbaric chambers.
1.5 ATA Hyperbaric Chambers: soft or mild hyperbaric chamber
- Underwater equivalent: about 16.5 feet (5.0 meters).
- What it means: Often treated as the upper end of what people call mild HBOT. This is the common pressure used in many research trials looking at non-standard or experimental uses. These hyperbaric chambers draw in air from the room, matching the oxygen concentration we normally breathe. Users often add an oxygen concentrator to raise their oxygen intake during sessions.
- How it feels: Clearly pressurized. You will notice the change more than at 1.3 or 1.4, but most people adapt quickly with standard ear-clearing techniques.
- Primary Users: Users who want something stronger than basic mild therapy, and people who plan to use sessions frequently and want measurable effects without moving to full clinical pressures. These hyperbaric pressures are not FDA-approved in the USA at this time for the soft hyperbaric chambers.
1.6 ATA Hyperbaric Chambers: upper end of mild-soft or mild hyperbaric chamber
- Underwater equivalent: about 20 feet (6.0 meters).
- What it means: Near the line between mild soft hyperbaric chambers and higher hard chambers. You will feel it. These hyperbaric chambers pull in air from the room, which has the same oxygen concentration as the air we breathe every day. Many users attach an oxygen concentrator to the chamber to increase their oxygen intake during sessions.
- How it feels: More pronounced ear pressure during compression and decompression. Some users prefer slower ramping of pressure for comfort.
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Primary Users: Experienced users who are comfortable with equalizing and want the highest soft hyperbaric chamber setting. These hyperbaric pressures are not FDA-approved in the USA for soft hyperbaric chambers at this time.
2.0 ATA Hyperbaric Chambers: clinical strength - hard-sided chamber
- Underwater equivalent: about 33 feet (10 meters).
- What it means: This is what most hospitals and medical centers use for many official HBOT protocols. It is stronger, and a trained medical staff oversees sessions as these units use 100% oxygen.
- How it feels: Stronger pressure that needs careful ear equalizing. Sessions are often longer, done under supervision, and can take place in a monoplace hyperbaric chamber that accommodates multiple users.
- Who likes it: Clinics and centers, and some buyers who want a clinical-level chamber and understand how to handle higher pressures. Keep in mind that risks and monitoring needs rise at and above this level. Studies show adverse reactions become more common at pressures above 2.0 ATA, so clinical oversight is the norm.
How Long Are Hyperbaric Sessions, and What Is The Frequency?
Many studies and clinical programs use 60 to 90 minutes per session, often daily, for a set course of treatment. Shorter or longer sessions show up depending on the protocol and pressure. If you plan to use a home portable hyperbaric chamber regularly, consider how many sessions per week you expect and whether you prefer short daily sessions or occasional longer ones. Two Hbot sessions can be completed in a day, but a 4-hour break is required between sessions.
HBOT Safety Basics: Recommended Guidelines
- Ear care: Pressurizing and depressurizing affect your ears. If you get ear pain, slow the pressurization down and try common ear-equalizing tricks such as swallowing, yawning, or the Valsalva maneuver. There is no need to have any ear pain!
- Don’t push through sharp pain: Mild pressure discomfort is common. Sharp pain is a sign to stop and slow down pressurization.
- Supervision for higher pressures: If you’re using 2.0 ATA or above, strong consideration should be given to trained oversight or using a center. Higher pressure raises the chance of oxygen toxicity or other reactions.
- Start low and build confidence: If you are new, start at 1.0 ATA or 1.4 first. You can always increase your pressure if you want stronger sessions and spend more time in the hyperbaric chamber.
Common HBOT Misunderstandings, Cleared Up
“More pressure equals better every time.”
Not necessarily. The proper hyperbaric oxygen therapy pressure depends on the goal, medical diagnosis, tolerance, and frequency.
Some conditions studied in traditional hyperbaric oxygen therapy are treated at 2.0 ATA or higher. Some newer studies show measurable benefits at mild pressures such as 1.3 to 1.5 ATA. Bigger numbers are not automatically better for every person. We have seen many doctors prescribing lower pressures for head-related injuries, as they are more tolerable and offer significant benefits.
We recommend consulting with your doctor. If you don’t have a physician trained in hyperbarics, contact Healing The Hyperbaric Way, and we will connect you with one of ours.
“If two people buy the same setting, they’ll get the same results.”
Everyone’s body reacts differently. Tolerance, session timing, frequency, and health goals alter outcomes.
How To Choose A Hyperbaric Chamber: Checklist
- How often can I use my hyperbaric chamber? Most folks are using it 5-6 days a week when they get started. Consult with your doctor for your recommended protocol.
- Is this for home use or a clinic? Clinics commonly use 2.0 ATA or higher. Home users often choose 1.3 to 1.6 ATA.
- Will multiple people use this Hbot? Pick a pressure and a size for a hyperbaric chamber that both users can comfortably fit into.
- Do you want clinically studied pressure? For specific medical indications, research protocols often use 2.0 ATA or higher. For lifestyle or wellness usage, many people opt for the mild hyperbaric chambers so they can have more accessibility by purchasing them for home use.
- Most importantly: Consider the user's mobility. Can they easily get in and out of the hyperbaric chamber?
How To Equalize Your Ears During Your Session
- Swallow frequently.
- Chew gum during your pressurization or depressurization period.
- Yawn and hold the throat relaxed.
- Perform gentle Valsalva if needed: pinch nose, blow gently through the nose while keeping the mouth closed. Don’t force it.
- If pressure builds too fast, ask to slow it down. All hyperbaric chambers let you control how quickly pressure changes through a balance valve, so there is no reason to go too quickly and have your ears hurt.
What the Research Shows About Hyperbaric Pressure Levels
- Mild pressures like 1.3 to 1.5 ATA are being studied in areas such as exercise recovery, cognitive issues, Lyme disease, Autism, strokes, concussions, and wellness applications. Several recent trials and reviews report physiological effects at these pressures. Unfortunately, these health conditions are considered off-label and are not approved by insurance companies at this time.
- At this time, many established clinical indications studied by the hyperbaric community use 2.0 ATA or higher. That is the setting most often used in hospital-based treatment protocols and is approved by insurance companies. Wounds and radiation injury are among the conditions considered on-label and recognized by insurance.
- Safety reviews show that adverse events become more common above 2.0 ATA, which is why clinical oversight is recommended for higher pressures.
Hyperbaric Pressure Levels: Quick Comparison Chart
What Pressures Are Soft Hyperbaric Chambers Versus Hard Chambers?
Soft Chambers
- Start at 1.3 ATA (about 4.0 to 4.4 PSI).
- They are designed for home use and fall in the category of “mild hyperbaric chambers also known as portable or soft chambers.”
Hard Chambers
- Can reach 1.5, 1.6, 2.0 ATA, and higher.
- These Hbots are hard-sided or made of metal and have higher pressures. They are typically found in hospitals or clinics.
Conclusion
Most home users choose soft hyperbaric chambers in the 1.3-1.5 ATA range. These pressures offer significant benefits for personal therapy. For wellness centers or more clinical-focused use, a wider range of pressures may be appropriate. Pressures of 2.0 ATA and above are available only in hard chambers.
Healing The Hyperbaric Way offers hyperbaric chamber models across the 1.3 - 2.0 ATA range and can help match a model to your comfort level and health goals.