# How many litres per minute of oxygen per hospital bed?

**How many litres per minute of oxygen should be planned per hospital bed, ICU bed and theatre?**

NHS England's HTM 02-01 (2026) gives wards a design flow of 10 L/min per terminal unit (typical use 6 L/min), plans critical care at 60 L/min per bed space where high-flow ventilation is used (10 L/min without), and theatres at 50 L/min for the first operating room plus 10 L/min for each other.

HTM 02-01 states that pipeline flow cannot be predicted precisely, but gives guideline flows that have proved adequate in practice. It sets a design flow for each terminal unit and, for each department, a diversified flow Q calculated from the number of beds, treatment spaces or rooms in use, not from the number of terminal units. A critical care bed space, for example, may have four or more oxygen terminal units.

| Area | Design flow per terminal unit | Typical flow | Planning basis in HTM 02-01 |
|---|---|---|---|
| In-patient accommodation | 10 L/min | 6 L/min | Use of NIV, BiPAP and CPAP is taken into account with the high-flow ventilation calculations |
| Critical care units | 60 L/min | 15 L/min | All bed spaces assumed occupied and using oxygen; Q = 60 L/min per bed space with high-flow ventilation, 10 L/min without; each terminal unit able to deliver 100 L/min |
| Operating suites | 50 L/min | 20 L/min | Q = 50 L/min for the first operating room and 10 L/min for each of the others; each terminal unit in operating and anaesthetic rooms able to pass 100 L/min |

## Other figures in use

- Portugal: the ACSS specification ET 03/2006 (revised 2024) recommends that all intensive care and emergency observation beds can deliver high-flow oxygen up to 60 L/min, and that 20% of inpatient beds can do the same.
- COVID-19 treatment centres: WHO's interim guidance of 4 April 2020 used an average of 10 L/min per severe and 30 L/min per critical COVID-19 patient, in a sample plan for a 100-bed facility. WHO notes that the sample is based on a patient count, and that typical quantification would be based on the equipment available.
- Patient devices: WHO's Foundations of medical oxygen systems (2023) lists 1 to 5 L/min for a nasal cannula and 10 to 60 L/min for high-flow nasal oxygen.

## From beds to plant size

HTM 02-01 sizes the supply line from the plant to the distribution system for the full design flow of the system plus 25%, and notes that PSA regeneration uses a proportion of the product gas, which should be taken into account when sizing the plant. To compare a total in litres per minute with plant capacities, WHO's 2020 interim guidance multiplies by 60 to get litres per hour and divides by 1,000 to get m³/h. ULTRAOX ST models range from 0.32 to 164 m³/h per unit. See also [how to estimate a hospital's oxygen demand](https://library.ultracontrolo.com/answers/how-to-estimate-hospital-oxygen-demand/).

### Is the flow per bed the same as the flow per outlet?

No. HTM 02-01 gives design flows per terminal unit, but calculates diversified flows from the number of beds, treatment spaces or rooms, and a critical care bed space may have four or more oxygen terminal units.

### Is 60 L/min per ICU bed always needed?

No. HTM 02-01 (2026) reduces it to 10 L/min per bed space where there is no requirement for high-flow ventilation.

## Sources

- [NHS England, HTM 02-01 Part A (2026), paragraphs 4.6, 4.13, 4.45, 4.49 to 4.51, 4.54, 6.110 and Table 2](https://www.england.nhs.uk/wp-content/uploads/2016/05/health-technical-memorandum-02-01-medical-gas-pipeline-systems-part-a-design-installation-validation-verification-aug-2026.pdf)
- [ACSS, ET 03/2006 v.2024 Gases medicinais e aspiração, section 6.7](https://www.acss.min-saude.pt/wp-content/uploads/2016/10/ET-03_2006_v2024-Gases-medicinais_VF.pdf)
- [WHO, Oxygen sources and distribution for COVID-19 treatment centres, interim guidance (4 April 2020), Table 1](https://www.who.int/publications/i/item/oxygen-sources-and-distribution-for-covid-19-treatment-centres)
- [WHO, Foundations of medical oxygen systems (17 February 2023), Figs 1.9 and 1.10](https://www.who.int/publications/i/item/WHO-2019-nCoV-Clinical-Oxygen-2023.1)
- [ULTRAOX ST datasheet, p. 5 (model table)](https://www.ultracontrolo.com/products/ultraox-st)

Reviewed: 2026-10-22. Ultra Controlo engineering. https://library.ultracontrolo.com/answers/how-many-litres-of-oxygen-per-bed/