1.5 ATA vs 2.0 ATA Hyperbaric Chambers: What’s the Difference?

If you’ve been looking into hyperbaric oxygen chambers, you’ll probably have come across two common pressure ratings: 1.5 ATA and 2.0 ATA.

But what do those numbers actually mean, and does a higher pressure automatically make one chamber better than another?

At Oxygens, we supply both 1.5 ATA and 2.0 ATA hyperbaric chambers throughout the UK. One of the questions we’re regularly asked is which pressure is most suitable for a particular setup.

The answer depends on how the chamber will be used, its construction, the oxygen delivery system and whether it’s intended for home, wellness or professional use.

Here’s what you need to know before choosing.

What Does ATA Mean in Hyperbaric Oxygen Therapy?

ATA stands for Atmospheres Absolute. It’s a measurement of pressure that includes the atmospheric pressure around us.

At sea level, normal atmospheric pressure is approximately 1.0 ATA.

Inside a hyperbaric chamber, that pressure is increased.

• 1.0 ATA: Normal atmospheric pressure at sea level.

• 1.5 ATA: One and a half times normal atmospheric pressure.

• 2.0 ATA: Twice normal atmospheric pressure.

These are absolute pressures, not the additional pressure above atmospheric conditions.

For example, a chamber operating at 1.5 ATA is approximately 0.5 atmospheres above normal atmospheric pressure.

The higher the ATA rating, the greater the pressure inside the chamber.

However, pressure is only one part of the picture. The oxygen being breathed, the equipment used and the intended application are equally important.

1.5 ATA vs 2.0 ATA: Key Differences

The following table explains the main differences between the two pressure levels.

A chamber’s maximum pressure rating does not, by itself, establish whether it is suitable for medical treatment.

How Does Pressure Affect Oxygen Delivery?

Hyperbaric chambers increase the pressure around the person inside them.

When someone breathes oxygen at increased pressure, the amount of oxygen that can dissolve in the blood plasma increases. This is one of the principles behind medically supervised hyperbaric oxygen therapy.

However, there’s an important distinction between chamber pressure and the concentration of oxygen being breathed.

For example, breathing normal air inside a pressurised chamber is not the same as breathing medical-grade oxygen under the same pressure.

The oxygen delivery system, mask or hood, breathing gas concentration and operating pressure all influence oxygen exposure.

This is why two chambers with the same ATA rating may not provide equivalent conditions.

What Is a 1.5 ATA Hyperbaric Chamber?

A 1.5 ATA chamber operates at up to one and a half times normal atmospheric pressure.

At Oxygens, our 1.5 ATA range includes sit-up, lie-down and larger XL chamber designs.

These chambers are designed for home and wellness environments, with different configurations to suit the available space and user preferences.

Depending on the model, features can include:

• Comfortable seated or reclining positions.

• Internal controls.

• Separate oxygen concentrator and mask arrangements.

• Different chamber sizes and access options.

• Professional installation and operating instruction.

A 1.5 ATA chamber may be appropriate for customers seeking a lower-pressure chamber for its intended non-medical application.

It should not be assumed to provide the same treatment conditions or clinical outcomes as hospital-based HBOT.

Why Choose a 1.5 ATA Chamber?

A 1.5 ATA model may be worth considering if you’re looking for a home or wellness chamber and don’t require the additional pressure capability of a 2.0 ATA system.

The chamber’s size, accessibility, comfort, oxygen equipment and operating requirements should all be considered before making a decision.

Oxygens offers 1.5 ATA chambers to purchase or hire, with standard hire starting from £585 per month including VAT.

What Is a 2.0 ATA Hyperbaric Chamber?

A 2.0 ATA chamber operates at twice normal atmospheric pressure at sea level.

Chambers capable of this pressure generally require a more substantial design and appropriate pressure-rated components.

At Oxygens, our 2.0 ATA range includes hard-shell chambers such as the Winslet, with features that vary by model.

These can include:

• Rigid chamber construction.

• Spacious seated or reclining interiors.

• Integrated control systems.

• Pressure monitoring.

• Oxygen and carbon dioxide monitoring.

• Internal communication systems.

• Professional installation and operator training.

A 2.0 ATA chamber offers greater pressure capability than a 1.5 ATA model, but this does not automatically mean it is the right choice for every customer.

The chamber must be suitable for its intended purpose, and higher-pressure operation requires appropriate safety procedures.

Is 2.0 ATA Better Than 1.5 ATA?

Not necessarily.

A 2.0 ATA chamber can achieve a higher operating pressure, but whether that is useful depends on the application.

For home and wellness use, the additional capability may not be required.

For medical HBOT, treatment pressure is determined by a clinical protocol and the patient’s circumstances. A chamber being rated to 2.0 ATA does not, on its own, make it suitable for clinical treatment.

Is 1.5 ATA Hyperbaric Therapy the Same as Medical HBOT?

No. It’s important to distinguish lower-pressure chamber use from medically prescribed hyperbaric oxygen therapy.

Medical HBOT typically involves breathing medical-grade oxygen in a suitably equipped chamber under professional supervision.

Established clinical protocols commonly use pressures around 2.0–3.0 ATA, depending on the condition being treated.

Lower-pressure home and wellness chambers should not be considered equivalent to these systems.

Clinical HBOT may be used for certain recognised medical conditions, including decompression illness and selected serious wounds, but those treatments require appropriate medical assessment and specialist facilities.

If you’re considering hyperbaric oxygen therapy for a medical condition, seek advice from a qualified healthcare professional rather than selecting a chamber based solely on its pressure rating.

Are Higher Hyperbaric Pressures More Dangerous?

All pressurised chambers require appropriate safety precautions, regardless of whether they operate at 1.5 ATA or 2.0 ATA.

Pressure changes can affect the ears and sinuses, and some individuals may have medical conditions that make hyperbaric exposure unsuitable.

Potential risks associated with hyperbaric exposure include:

• Ear and sinus barotrauma.

• Difficulty equalising pressure.

• Claustrophobia or discomfort.

• Oxygen-related complications, depending on the breathing gas and exposure.

• Fire hazards where oxygen-enriched conditions are present.

Higher pressures can introduce additional operating considerations, but safety depends on much more than pressure alone.

Equipment design, maintenance, oxygen delivery, training and following the manufacturer’s instructions are all essential.

Never operate a chamber beyond its rated pressure or outside its approved operating procedures.

Choosing Between a 1.5 ATA and 2.0 ATA Chamber

If you’re considering purchasing a hyperbaric chamber, we’d suggest starting with a few practical questions.

Where Will the Chamber Be Installed?

A chamber intended for home use may have different space, access and installation requirements from equipment installed in a professional facility.

Check the available room, electrical requirements, ventilation and access before choosing a model.

Who Will Be Using It?

Consider the user’s height, mobility, comfort and preferred seating or reclining position.

For some customers, the internal space and access arrangements may be more important than the difference between 1.5 and 2.0 ATA.

What Is the Intended Application?

For home and wellness use, choose equipment that is designed and specified for that purpose.

For medical treatment, seek clinical advice and use a facility equipped to provide the prescribed treatment.

What Support Is Available?

Buying a hyperbaric chamber is not simply a matter of choosing a pressure rating.

Installation, training, maintenance, servicing and technical support should all be part of the decision.

At Oxygens, we provide UK installation, operator training and ongoing technical support for our chamber range.

Frequently Asked Questions

What is the difference between 1.5 ATA and 2 ATA?

A 1.5 ATA chamber operates at one and a half times normal atmospheric pressure, while a 2.0 ATA chamber operates at twice normal atmospheric pressure. The difference affects chamber design and operating requirements, but pressure alone does not determine suitability or effectiveness.

Does 2 ATA deliver more oxygen than 1.5 ATA?

At the same inspired oxygen concentration and under otherwise comparable conditions, higher pressure increases the partial pressure of oxygen. Actual oxygen exposure also depends on the oxygen delivery system and breathing gas.

Can I use a 1.5 ATA chamber at home?

Some 1.5 ATA chambers are designed for home use, subject to their specifications, suitability, installation requirements and operating instructions. Oxygens can explain the requirements for its home chamber range.

Can a soft-shell chamber operate at 2 ATA?

Not unless it has been specifically designed, rated and approved for that pressure. Never exceed the manufacturer’s stated operating limits.

Is a 2 ATA chamber suitable for medical treatment?

A pressure rating of 2.0 ATA alone is not enough to establish suitability for medical HBOT. Clinical use requires appropriate equipment, oxygen delivery, safety procedures and professional oversight.

Which hyperbaric chamber should I buy?

The right chamber depends on your intended application, available space, budget, access requirements and the equipment specification. Our team can help you compare the options.

Explore 1.5 ATA and 2.0 ATA Chambers at Oxygens

Whether you’re looking for a comfortable chamber for home use or a larger hard-shell system for a professional environment, we can help explain the differences.

Oxygens supplies a range of 1.5 ATA and 2.0 ATA hyperbaric chambers throughout the UK, with installation, training and ongoing technical support.

Explore our hyperbaric chamber range or contact Oxygens to discuss your requirements.

We’ll help you compare the available models and understand which specification is appropriate for your intended use.