05 · Installation
Site and electrical requirements
A pre-installation checklist is only useful if you know where each line comes from. Some of these are code. Some are the National Electrical Code. Some are your manufacturer’s number. And several of the dimensions people ask about are not codified anywhere.
The reference stack
What a contractor actually works from.
One manufacturer’s published building-service document lays out the stack plainly: comply with all local fire and building codes; use qualified licensed construction personnel and document all activities; engage a licensed medical gas supplier and certified medical gas plumber; and use a licensed electrician to ensure proper grounding of the chamber and installation of the necessary outlets for electrical power. It then cites NFPA 99 — Chapter 14 for hyperbaric facilities, and the medical gas and vacuum piping chapter — along with NFPA 70 for electrical safety and NFPA 101, and adds UHMS facility design and accreditation guidelines plus state health-department requirements. It warns that the local authority having jurisdiction may require full compliance with the Uniform Building Code, NFPA 50, NFPA 55, NFPA 70, NFPA 99 and NFPA 101 before operations begin (Pan-America Hyperbarics). That document is specific to one chamber model; the codes it references are general.
NFPA 70, the National Electrical Code, is enforced in all fifty states, and its current edition is 2026 (the NFPA 70 code development page).
The NFPA 101 reference matters more than it looks. UHMS quotes NFPA 101 as requiring that all occupancies containing hyperbaric facilities comply with NFPA 99 unless otherwise modified, with the annex stating that although the scope of NFPA 99 is limited to health care occupancies, the intent is that this requirement be applied to hyperbaric facilities used in all occupancies (UHMS consumer warning article). That is the mechanism by which a chamber in a wellness studio or a private office is not outside the code’s reach.
Site work is the cheapest thing to fix on paper and the most expensive thing to fix after a chamber is on a truck. Our installation and commissioning scope starts with a site review against this list, not after the crate opens.
Checklist
Every line, labeled by source
| Item | Requirement | Source |
|---|---|---|
| Dedicated room | Room housing a Class A or Class B chamber is for exclusive hyperbaric use. | Codified NFPA 99, Ch. 14 |
| Fire-rated construction | Two-hour rating with one-and-a-half-hour B-label doors for Class A chambers and their ancillary equipment. | Codified NFPA 99, Ch. 14 |
| Sprinklers | NFPA 13 wet-pipe sprinklers (or NFPA 750 water mist) in the chamber room and ancillary rooms. | Codified NFPA 99, Ch. 14 |
| Extinguisher in room | 2-A:10B:C portable extinguisher. | Codified per NFPA Journal |
| Floor loading | Supporting foundation designed to carry the chamber, including the added stress of on-site hydrostatic testing with water weight. No numeric psf value is codified. | Codified NFPA 99, Ch. 14 |
| Grounding | Hull grounded per the National Electrical Code grounding article; resistance between grounded hull and electrical ground not to exceed 1 ohm; conductive surfaces continuously bonded to the hull. | Codified NFPA 99, Ch. 14 + NFPA 70 |
| Branch circuits | In-chamber branch circuits 125 V / 15 A maximum; ungrounded (isolated) power with a line isolation monitor per the NEC health care facilities article; portable cord-connected equipment 120 V / 2 A maximum. | Codified NFPA 99, Ch. 14 + NFPA 70 |
| Dual power sources | Two independent sources; an NFPA 70 Article 700 emergency system if the facility is not in a hospital; life-support loads on the critical branch restored within 10 seconds. | Codified NFPA 99, Ch. 14 |
| Compressor circuits | Two or more compressors, each on a separate branch circuit. | Codified NFPA 99, Ch. 14 |
| Compressor intake siting | Intake located away from vehicle or engine exhaust and building exhaust. | Codified NFPA 99, Ch. 14 |
| Exhaust to outdoors | Chamber exhaust piped outside the building; an independent line for each Class B chamber; screened; signed as oxygen exhaust. | Codified NFPA 99, Ch. 14 |
| Gas shutoffs | Shutoff valves where piped gases enter the hyperbaric room. | Codified NFPA 99, Ch. 14 |
| Chamber interior temperature | A Class A chamber not used as an operating room is kept comfortable, which the code describes as usually 22°C plus or minus 2°C (75°F plus or minus 5°F). | Codified (advisory phrasing) |
| Room temperature (monoplace) | One manufacturer specifies a chamber operating temperature range of 50–100°F and recommends the room housing the chamber be kept at 68–74°F for patient comfort. | Manufacturer via UHMS |
| Chamber grounding hardware | A manufacturer sells a wall-mount ground kit and states that grounding is a vital safety consideration and an NFPA 99 requirement for Class B chambers. | Manufacturer |
| Emergency generator | The UHMS Safety Committee’s position is that a generator is not required unless the facility will treat emergent hyperbaric indications and use ancillary medical devices, since monoplace chambers are gas-driven — but Colorado has required a backup generator or a suitably sized UPS even for pneumatically operated chambers. | Guidance + state variation |
| Occupancy classification | UHMS notes that a CMS memo has been interpreted by some authorities as requiring Ambulatory Health Care occupancy regardless of chamber count, leading to a best-practice recommendation to build to that occupancy. | Industry practice |
Sources: UpCodes Chapter 14, UpCodes chamber ventilation provisions, the UHMS accreditation manual, the NFPA Journal, Pan-America Hyperbarics building service requirements and the Sechrist ground kit datasheet.
Ventilation and gas
Air quality and flow
- Compressed air supplied to a chamber must meet a recognized medical or breathing-air quality grade, and treatment gases — breathing air and oxygen — must be USP grade.
- Class A chambers require a ventilation rate of 3 ft³/min per occupant who is not on an overboard dump system.
- All gas outlets inside and outside the chamber must be labeled per CGA C-7.
- Oxygen and other gases shall not be introduced in liquid state. Flammable gases shall not be used or stored inside the chamber or within the hyperbaric facility, and hazardous materials and flammable gases shall not be stored in the room housing the chamber.
Sources: UpCodes Chapter 14 and the UHMS accreditation manual.
Straight answers
Three numbers that do not exist
Not codified
No minimum clearance in inches on each side of a vessel, and no service-access aisle width, was found in NFPA 99, ASME PVHO-2, or any other authoritative source reviewed for this library. This is manufacturer- and AHJ-driven. Use your chamber’s installation manual.
Requirement, no number
The code requires a foundation designed to support the chamber including hydrostatic-test water weight, and states no pounds-per-square-foot value. Your manufacturer’s drawings and a structural review provide the number.
No codified range
None found. UHMS notes qualitatively that HVAC-controlled humidity affects static control in the chamber room, and one manufacturer recommends a room temperature of 68 to 74°F. Anything more specific is a product specification, not a code figure.
If a vendor gives you one of those three numbers and calls it a code requirement, ask which code and which edition. That question resolves most of these conversations.
Hyperbaric Service Pros installs, services, and maintains hyperbaric equipment. We are not a medical facility and do not provide medical advice or treatment. Technical information on this site is general reference only — always follow your chamber manufacturer's documentation and the codes enforced in your jurisdiction.
Sources
Every claim on this page, traced to its source
- NFPA 99 Chapter 14, Hyperbaric Facilities — UpCodes public viewerhttps://up.codes/viewer/centers-for-medicare-and-medicaid-services/nfpa-99-2012/chapter/14/hyperbaric-facilities
- NFPA 99 Chapter 14, chamber ventilation provisions — UpCodeshttps://up.codes/s/chamber-ventilation
- NFPA 70, National Electrical Code — official code page (current edition 2026)https://www.nfpa.org/codes-and-standards/nfpa-70-standard-development/70
- NFPA Journal, “Under Pressure,” Brian O’Connor, Aug. 23, 2021https://www.nfpa.org/news-blogs-and-articles/nfpa-journal/2021/08/23/nfpa-13-august
- UHMS Clinical Hyperbaric Facility Accreditation Manual, 4th ed.https://www.uhms.org/images/Accreditation-Documents/Fourth_Edition_UHMS_Accreditation_Manual_Final.pdf
- UHMS Safety Committee FAQ — standards and codeshttps://www.uhms.org/tl/resources/featured-resources/medfaqs-frequently-asked-questions-faq/safety-technical/standards-and-codes.html
- UHMS, “Consumer Warning: The Dangers of Soft-Sided Bag Chambers”https://uhms.org/pressure-other-articles/1542-consumer-warning.html
- Pan-America Hyperbarics — building service requirements for a specific chamber modelhttps://panamericahbo.com/building-service-requirements-for-the-pah-s1-3200/
- Sechrist wall-mount ground kit datasheethttps://www.sechristusa.com/hy/_files/ugd/e7a8c6_968a2c998fdc415ba64fc47d22bcba01.pdf
Start a work order
Tell us the chamber, the site, and the timeline.
Make, model, serial number, photos, site address — send it all in one text or email and we can scope, price or diagnose it without a round of phone tag. Complete requests get worked first, simply because they can be.