01
Pressure: 1.2 to 3.0 ATA, and what each band changes about the hardware
Pressure is not a comfort setting. It determines what the vessel has to be, what the door and viewports have to be, what the relief valves have to do, and which regulatory record applies. This table is about the chamber, not about physiology — for the published exposures used in research, see the evidence table.
| Pressure band | Typical construction | What changes about the chamber | Regulatory position | Models in this band |
|---|---|---|---|---|
| 1.2 – 1.4 ATA ≈3 – 6 psi |
Fabric / semi-rigid, or hard shell operated low | Fabric bladder chambers in this band are inflated with ambient air by an electric compressor. The two cleared fabric families operate at 3–4 psi (1.2–1.3 ATA) and 1.5 ATA respectively. | FDA's cleared indication for the fabric chambers examined here is acute mountain sickness, prescription only. FDA states it has not cleared these bags for use with oxygen tanks or oxygen concentrators. FDA 510(k) K072757 — Summit to Sea Dive / Shallow Dive / Grand Dive · FDA 510(k) K220290 — Revitalair 430+ · FDA consumer update 'Hyperbaric Oxygen Therapy: Get the Facts' (content current as of 07/26/2021; live URL now 404, archived capture) |
Prestige Pavilion of Power (1.4), OxyHealth Vitaeris 320 / Respiro 270 / Quamvis 320 (1.3), Summit to Sea Shallow Dive / Dive (1.3), Newtowne Tent (1.3), OxyNova 7 (1.4) |
| 1.5 – 1.6 ATA ≈7 – 9 psi |
Reinforced fabric, or entry hard shell | The step from a bag to a reinforced or steel vessel usually happens here. Hard shells in this band pressurise faster than an inflating fabric chamber and carry rigid door hardware and relief valves. | Revitalair 430+, a semi-rigid polyester chamber with aluminium rings rated no greater than 1.5 ATA, is cleared for acute mountain sickness under prescription of a health professional, for physician offices and health institutions. FDA 510(k) K220290 — Revitalair 430+ |
Prestige Vessel of Power / Sphere of Power (1.5), Macy-Pan HP1501 family (1.6) |
| 2.0 ATA ≈15 psi |
Steel or acrylic hard shell only | At 2.0 ATA the vessel, door, viewports and relief valves are engineered pressure equipment. Published clinical literature describes the reviewed hyperbaric exposures as 1.9–3.0 ATA, and one review notes that most middle-ear barotrauma occurs during the first stage of compression, described as equivalent to 2 ATA. | FDA recognises ASME PVHO-1 (pressure vessels for human occupancy) and NFPA 99 as consensus standards for this product code. Ask for the PVHO conformity documentation, not a verbal claim. ASME PVHO-1 and NFPA 99 recognised as consensus standards for product code CBF · FDA Product Classification — chamber, hyperbaric (CBF) |
Prestige Grand Vessel of Power / Grand Sphere of Power / Grand Pavilion of Power, Macy-Pan HP2202-75 |
| 2.5 ATA ≈22 psi |
Steel hard shell | Published protocols at this pressure typically add scheduled air breaks: one 2.5 ATA study used two 45-minute oxygen periods separated by five minutes of air; another used three 20-minute periods. A chamber sold at this pressure should support that operation, not just reach the number. | Same Class II, 510(k), product code CBF pathway. Pressure alone does not change the regulatory class. FDA Product Classification — chamber, hyperbaric (CBF) |
Prestige Grand Vessel of Power Pro |
| 3.0 ATA 30.0 psig |
Acrylic or steel clinical hard shell | This is clinical monoplace territory. Sechrist publishes a relief-valve setting (35–36 psig), an emergency vent rate (30 psig to 0 in under 120 seconds), a purge rate of 80–400 lpm and an operating temperature and humidity envelope. If a chamber claims 3.0 ATA and cannot produce that list, the claim is unverified. | Class II, 510(k), product code CBF. Sechrist holds several clearances including K140559 (2014). Sechrist Industries — 'H' Chamber catalog (manufacturer PDF) · FDA 510(k) database, product code CBF (openFDA) |
Sechrist 3300H / 3600H / 4100H, OxyHealth Fortius 420 (up to 3.0 ATA, 29.4 psi) |
Hyperbaric chambers are Class II devices, product code CBF, cleared through 510(k) — a finding of substantial equivalence to a predicate device, not a PMA approval. 69 clearances exist under that product code, the most recent K240569 (2024). FDA 510(k) database, product code CBF (openFDA) · FDA Product Classification — chamber, hyperbaric (CBF)
02
Sizing: chamber internal dimensions against measured body dimensions
The specification that eliminates the most models fastest is width. Below are measured population figures. Compare them against the internal diameter in the comparison table — and note how many manufacturers publish only one dimension set without saying which it is.
Where a chamber's internal figure is not published, this comparison cannot be completed from public information, and no honest workaround exists: subtracting an assumed shell thickness produces a number that looks like a measurement and is not one. Prestige Hyperbaric is in that position — its published figures are external and it does not publish verified internal dimensions — and so are several competitors, in the opposite direction. In every one of those cases the measurement has to come from the vendor in writing before you order, not from this table.
| Measurement | Male 5th | Male 50th | Male 95th | Female 5th | Female 50th | Female 95th | Why it decides fit |
|---|---|---|---|---|---|---|---|
| Bideltoid breadth (shoulder-to-shoulder, widest point across deltoids) | 17.76 in | 19.72 in | 21.93 in | 15.79 in | 17.68 in | 20.02 in | This is the number that decides whether a person fits a cylinder. A 26 in internal diameter chamber leaves roughly 4 in total clearance for a 95th-percentile male at the widest point of the body, before bedding. U.S. Army Natick — Anthropometric Survey (ANSUR) II Pilot Study, 2009 (DTIC ADA498172) |
| Biacromial breadth (bone-to-bone across the shoulders) | 14.84 in | 16.10 in | 17.36 in | 13.10 in | 14.41 in | 15.75 in | Smaller than bideltoid breadth and often quoted instead. If a vendor's fit claim is based on a shoulder number, ask which one. U.S. Army Natick — Anthropometric Survey (ANSUR) II Pilot Study, 2009 (DTIC ADA498172) |
| Standing height, adults age 20+ | — | 68.9 in (mean, men) | — | — | 63.5 in (mean, women) | — | Chamber internal length must exceed height plus room to lie without the crown or heels contacting the end walls. A 72 in internal length is marginal for a mean-height man. CDC/NCHS Vital and Health Statistics Series 3, No. 50 — anthropometric reference data, Aug 2021–Aug 2023 |
| Body weight, adults age 20+ | — | 199.0 lb (mean, men) | — | — | 171.8 lb (mean, women) | — | Clinical chambers publish an occupant weight rating (Sechrist 500–700 lb; Perry 700 lb; Macy-Pan HP2202 300 kg). Most consumer chambers here publish none. CDC/NCHS Vital and Health Statistics Series 3, No. 50 — anthropometric reference data, Aug 2021–Aug 2023 |
| Waist circumference, adults age 20+ | — | 103.0 cm (mean, men) | — | — | 97.9 cm (mean, women) | — | Relevant to entry through a rigid door aperture, which almost no manufacturer in this table publishes separately from cabin width. CDC/NCHS Vital and Health Statistics Series 3, No. 50 — anthropometric reference data, Aug 2021–Aug 2023 |
Breadth percentiles are from the U.S. Army ANSUR II Pilot Study (2009), a military population, which skews younger and fitter than the general public; height, weight and waist figures are NHANES means for U.S. adults aged 20 and over, August 2021–August 2023. Neither is a substitute for measuring the actual occupant. U.S. Army Natick — Anthropometric Survey (ANSUR) II Pilot Study, 2009 (DTIC ADA498172) · CDC/NCHS Vital and Health Statistics Series 3, No. 50 — anthropometric reference data, Aug 2021–Aug 2023
Five sizing rules that follow from those numbers
| Rule | Detail |
|---|---|
| Measure the occupant, not the average. | Bideltoid breadth at the widest point, seated height if the chamber is upright, and standing height. Two minutes with a tape measure eliminates most of the shortlist. |
| Compare against internal dimensions only. | Several manufacturers in the comparison table publish one dimension set without stating whether it is internal or external. Those are flagged in the table. A quoted external length of 106 in with an internal length of 90 in — Sechrist's published figures — is a 16 in difference. |
| Subtract the bedding. | A mattress and bolsters occupy internal height. OxyHealth lists a contoured mattress and bolsters as included items; that height comes out of the usable interior. |
| For upright chambers, the number you need is sitting height above the seat. | Only one manufacturer in this table publishes it: Newtowne states 38 in sitting height above the chair. Ask everyone else for it in writing. |
| Check the room before the chamber. | External footprint, door aperture on the path in, ceiling height, and floor loading. A 2,000 lb hard shell is a structural question. Prestige publishes weights of ≈800 lb, ≈1,600–2,000 lb and ≈2,000 lb across its hard shell line. |
03
Oxygen delivery: concentrator, flow, purity, interface, duty cycle
“Includes a 10 LPM concentrator” is four separate specifications wearing one label: flow, purity at that flow, outlet pressure, and the interface that puts the gas on a face. Published figures below, with the question each one implies.
| Specification | Published figures | What to ask | Source |
|---|---|---|---|
| Concentrator purity | 90–96% oxygen by volume for medical-grade concentrators; typical adsorption units produce about 90–93% at under 10 L/min | What purity at the flow you will actually run, not at the best-case flow? | Flexible oxygen concentrators for medical applications (2021) |
| Concentrator purity, published examples | CAIRE NewLife Intensity 10: 92% (+3.5/−3) at 2–9 LPM, 90% (+5.5/−3) at 10 LPM. Respironics Millennium M10: 92% ±4% at 8–10 LPM, 94% ±2% at 3–7 LPM. | Purity falls at the top of the flow range on both of these units. A '10 LPM' claim is not a 10 LPM purity claim. | CAIRE — NewLife Intensity specification table |
| Concentrator power draw | CAIRE NewLife Elite (5 LPM) 350 W; NewLife Intensity 8 410 W; NewLife Intensity 10 590 W. Respironics Millennium M10 600 W. | Power draw roughly doubles from a 5 LPM to a 10 LPM unit. This is the figure the cost calculator uses. | CAIRE — NewLife Intensity specification table |
| Concentrator outlet pressure | NewLife Elite 7–9 psig; NewLife Intensity 8 and 10 20 psig; Millennium M10 10–30 psi | Does the chamber's oxygen inlet require more pressure than the concentrator delivers? | CAIRE — NewLife Intensity specification table |
| Concentrator noise | NewLife Elite 48 dB(A); Intensity 8 52 dB(A); Intensity 10 55 dB(A); Millennium M10 under 50 dB | Where does the concentrator sit relative to the chamber and the room's occupants? | CAIRE — NewLife Intensity specification table |
| Chamber air supply | OxyNova 7: rotary vane, 183 L/min air delivery, above 160 L/min at working pressure. Macy-Pan all-in-one: 72 L/min. Sechrist purge rate: 80–400 lpm. Perry Sigma 40 air/oxygen supply: 40 scfm (1,130 lpm). | Air supply flow and purge rate are different specifications. Which one is being quoted? | OxyNova — OxyNova 7 technical specifications |
| Delivery interface — hood vs mask | A 1996 comparative study found an acceptable inspired oxygen fraction was reliably achieved with a continuously ventilated hood, or with trained supervision of a demand-valve oral-nasal mask system. | Which interface is included, and does it depend on supervision to work as intended? | Primary source |
| Mask fit | At sea level and 2.4 ATA, properly fitted masks produced 96–99% end-inspired oxygen; improperly fitted masks ranged from 64% to 100%. | Fit is a bigger variable than the concentrator's rating. Ask how fit is verified. | Primary source |
| Fabric chambers and oxygen | FDA states it has not cleared the zippered fabric altitude-sickness chambers for use with oxygen tanks or oxygen concentrators, and that people who do so create homemade HBOT devices, which can pose the risk of fire and suffocation. | If a vendor bundles a concentrator with a fabric chamber, ask them to reconcile that with FDA's statement in writing. | FDA consumer update 'Hyperbaric Oxygen Therapy: Get the Facts' (content current as of 07/26/2021; live URL now 404, archived capture) |
| Fire risk with high oxygen concentration | FDA's August 2025 letter states there is a heightened risk of fire with use of oxygen at a high concentration, and recommends grounding, staff training, monitoring and supervision, prohibited-item controls, and cotton clothing. | Which of those controls come with the chamber, and which are the buyer's problem? | FDA Letter to Health Care Providers, 25 Aug 2025 |
| Ventilation and oxygen accumulation | Measurements in a clinical chamber at 160, 220 and 280 kPa found local underventilation at some sampling points, and stated that oxygen accumulation in such zones can increase chamber-fire risk. | How is chamber atmosphere ventilated and where does the exhaust go? | Primary source |
Not medical advice. Nothing above states or implies a therapeutic effect. It is equipment specification, and it is here so that a buyer can tell two quotes apart.
04
The specification list to demand from any vendor
Sixteen items. A vendor who can answer all sixteen in writing is a different proposition from one who answers six. The benchmark column mostly quotes clinical manufacturers, because they publish the most and therefore set the standard the rest can be measured against.
| Demand this in writing | Why, and the published benchmark |
|---|---|
| Maximum operating pressure, in both ATA and psi | Get both units. Several manufacturers in the comparison table publish only one, and one publishes psi for some models and ATA for others. |
| Relief valve set pressure | Sechrist publishes 35.0 psig for the 3300H and 36.0 psig for the 3600H/4100H. If a vendor cannot state theirs, they may not know it. |
| Emergency vent rate | Sechrist: 30 psig to 0 psig in under 120 seconds, with two vent modes, one autonomous. |
| Internal dimensions, explicitly labelled internal | Plus external footprint including the machine cabinet and any stabiliser poles. Newtowne is the only manufacturer here that publishes frame width including stabiliser poles. |
| Door or entry aperture, separately from cabin width | No manufacturer in this table publishes it. Ask anyway; measure it on a demo unit. |
| Occupant weight rating | Published by Sechrist (500–700 lb), Perry (700 lb) and Macy-Pan HP2202 (300 kg). Not published by any consumer soft-shell brand here. |
| Chamber weight and floor loading | Prestige publishes ≈800 lb to ≈2,100 lb across its hard shell line. Ask what the load is per foot of contact area. |
| Electrical requirement per component | Chamber, compressor, concentrator and any air conditioner draw separately. Macy-Pan lists a 300 W air conditioner as an additional unit. |
| Compressor type and flow at working pressure | OxyNova publishes 'above 160 L/min at its working pressure' — flow at pressure, not free-air flow, is the meaningful number. |
| Concentrator model, purity at your flow, and power draw | Not the marketing LPM number. See the oxygen table above. |
| ASME PVHO-1 conformity documentation for any rigid vessel | FDA recognises ASME PVHO-1 and NFPA 99 as consensus standards for this product code. |
| FDA 510(k) K-number and the applicant name on that clearance | Verify it in FDA's own database. One data sheet in this table cites a K-number that FDA's records show belongs to a different company. |
| Written statement of the cleared indication | The fabric chambers examined here are cleared for acute mountain sickness, prescription only. That is the cleared indication, whatever the sales conversation is about. |
| Operating temperature and humidity envelope | Sechrist publishes 50–100 °F and 30–90% RH. Newtowne publishes −25 °F to 120 °F for its tent. |
| Sound level, measured with the unit running | OxyNova publishes under 60 dB(A). In 41 clinical centres at 2.4 ATA, measured in-chamber continuous sound ranged from 40.5 dB(A) without ventilation to 100.4 dB(A) with it. |
| Compression rate control | Most middle-ear barotrauma occurs during compression. Ask whether compression rate is adjustable and who controls it. |
Send this list as-is. If you want it filled in for a specific quote, email [email protected] or call 813-519-3232 — we install and service chambers from most of these manufacturers and we also sell equipment, so weigh our answer accordingly.