# How many medical gas outlets does each bed need?

**How many oxygen, air and vacuum outlets does each bed type need?**

Under HTM 02-01 (2026), the NHS England guidance, Table 1 gives typical outlet numbers: a general ward bed has 1 oxygen and 1 vacuum terminal unit, while an intensive care bed has 4 oxygen, 2 medical air and 4 vacuum; the table is a basis for design, not a prescription.

Table 1 of HTM 02-01 Part A (2026 edition), published by NHS England, lists typical numbers of terminal units (outlets) per bed space, cot, trolley space or room, by service: oxygen (O2), oxygen/nitrous oxide mixture (O2/N2O), medical air at 400 kPa (MA4), surgical air at 700 kPa (SA7), vacuum (VAC) and anaesthetic gas scavenging (AGSS). The guidance says the table provides typical types and values and is not intended to be prescriptive: it is a basis for design, and an informed design follows the four key stages of its Chapter 1 with a collaborative, multidisciplinary approach.

## Typical numbers in HTM 02-01 Table 1

| Location | O2 | MA4 | SA7 | VAC | AGSS |
|---|---|---|---|---|---|
| General ward, per bed space | 1 | none | none | 1 | none |
| Decant ward, per bed space | 2 | 2 | none | 2 | none |
| Renal, per dialysis station | 1 | none | none | 1 | none |
| Non-acute (community or hospice), per bed space | 1 | none | none | 1 | none |
| Emergency resuscitation room, per trolley space | 4 | 2 | none | 2 | none |
| Emergency minor treatment | 1 | none | none | 1 | none |
| Anaesthetic room | 1 | 1 | none | 1 | 1 |
| Acute operating theatre | 4 | 4 | 2 | 4 | 2 |
| Post-anaesthesia recovery stage 1, per bed space | 2 | 2 | none | 2 | none |
| Post-anaesthesia recovery stage 2, per bed space | 1 | none | none | 1 | none |
| Intensive care unit, per bed space | 4 | 2 | none | 4 | none |
| High dependency unit, per bed space | 4 | 2 | none | 4 | none |
| Neonatal unit, per cot space | 4 | 2 | none | 4 | none |

Where the table asks for dual circuits, as it does for intensive care, high dependency, neonatal cots and emergency resuscitation, the circuits should be split evenly to cover both sides of the bed or each pendant: with 4 terminal units on each side of the bed, 2 come from each circuit, and the numbers in the table are the total across both circuits. Dual pipeline circuits should also be provided to operating theatres where enhanced resilience is required at the point of surgery. Where no row matches, a similar use area from the table should be used where possible.

## Other rules that change the count

- An anaesthetic gas scavenging terminal unit should be provided whenever nitrous oxide and anaesthetic agents are available for anaesthetic procedures.
- LDRP rooms with birthing pools should get an additional oxygen/nitrous oxide terminal unit for use of the pool.
- Outlet numbers are not flow numbers: HTM 02-01 calculates [diversified flows](https://library.ultracontrolo.com/answers/what-is-a-diversity-factor/) from the number of bed spaces, treatment spaces or rooms where the procedure takes place, not from the number of terminal units, and notes that a critical care bed position may have four or more oxygen terminal units.

## Outside England

Other countries publish their own numbers. Portugal's ACSS specification ET 03/2006 (v.2024), for example, has an annex with the minimum number of outlets for oxygen, carbon dioxide, nitrous oxide, vacuum and medical air at 400 kPa and 700 kPa.

### Does HTM 02-01 make these numbers mandatory?

No. HTM 02-01 (2026) presents Table 1 as typical types and values, not intended to be prescriptive but providing a basis for design.

### How many outlets does an operating theatre have in HTM 02-01?

Table 1 lists 4 oxygen, 4 medical air (400 kPa), 2 surgical air (700 kPa), 4 vacuum and 2 AGSS terminal units for an acute operating theatre, on dual circuits.

## Sources

- [HTM 02-01 (2026) Part A, paragraphs 3.1, 3.15 and 4.6, Table 1 and its notes, NHS England](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, annex (minimum number of outlets), Portugal](https://www.acss.min-saude.pt/wp-content/uploads/2016/10/ET-03_2006_v2024-Gases-medicinais_VF.pdf)

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