# How much ventilation does a medical air or vacuum plant room need?

**How much ventilation and cooling does a medical air or vacuum plant room need, including in hot climates?**

HTM 02-01 (2026), the NHS England guidance, says cooling and ventilation for medical air and vacuum plantrooms should be determined with the compressor manufacturer or plant supplier, as the calculations are specific to each installation, keeping the room at 10 to 40 °C and no more than 10 °C above ambient.

HTM 02-01 (2026) says medical air, vacuum and AGSS plant should be housed in weatherproof enclosures, preferably in purpose-built plantrooms as part of the main building, and says medical air plant should not be in the same room as medical vacuum or AGSS plant. For the plantroom itself it asks for:

- Ventilation louvres at both high and low level, with the free area of the vent calculated rather than its total area, sited with regard to vehicles and other sources of contamination, and designed to keep out vermin and birds.
- Adequate natural ventilation, because medical air compressors generate considerable heat under maximum flow, and mechanical ventilation where natural ventilation is not practicable, as in deep-plan plantrooms.
- A room temperature within 10 to 40 °C, with ventilation rates that keep the plantroom no more than 10 °C above ambient; any additional heating by indirect means, without reducing natural ventilation.
- Compressor air intakes located externally where possible, but not as a substitute for ventilation for cooling.
- Cooling and ventilation requirements determined with the compressor manufacturer or plant supplier.

## Airflow for the machines

Medical air plant siting should give adequate airflow for three purposes: air intake to the compressors, cooling of the compressed air by the after-coolers, and cooling of the compressors. The after-coolers are air-cooled and may need ducting with forced ventilation, and compressor cooling airflow may need to be provided mechanically by a duplex system so that a failure does not compromise plant operation. For pump plant, the HTM asks for adequate airflow for pump cooling. Acoustic enclosures and plantroom design should not inhibit normal cooling.

## Hot climates

HTM 02-01 asks for manufacturers to be consulted on the range of operating temperatures the supply system is designed for, says refrigerator cooling may be required in extreme cases, and asks for plant area temperature and humidity to be risk-assessed for their ranges over the course of a year.

## The Portuguese specification

ACSS ET 03/2006 (revised in June 2024) places the medical air compressor plant and the medical vacuum plant each in its own room in the technical zone, ventilated according to the heat given off by the equipment, and sends the vacuum exhaust to an outdoor point away from air intakes.

## Ultra Controlo equipment

The ULTRAAR SCA datasheet describes its scroll compressors as air-cooled, with a large passage radiator and a fan mounted on the main shaft. ULTRAVAC CLP vacuum pumps are air-cooled.

### Can medical air and vacuum plant share a room?

Not under HTM 02-01 (2026), which says medical air plant should not be located in the same room as the medical vacuum or AGSS plant.

### Is air conditioning required?

HTM 02-01 asks for adequate natural ventilation, mechanical ventilation where that is not practicable, and says refrigerator cooling may be required in extreme cases, after consulting the manufacturer on operating temperatures.

## Sources

- [NHS England, HTM 02-01 Medical gas pipeline systems, Part A (2026), paras 7.17, 7.18, 7.21, 7.30, 7.45, 17.122, 17.125 and 17.134 to 17.147](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 Especificações técnicas para gases medicinais e aspiração em edifícios hospitalares, sections 4.6.1 and 4.8](https://www.acss.min-saude.pt/wp-content/uploads/2016/10/ET-03_2006_v2024-Gases-medicinais_VF.pdf)
- [ULTRAAR SCA datasheet, p. 2](https://www.ultracontrolo.com/products/ultraar-sca)
- [ULTRAVAC CLP datasheet, p. 2](https://www.ultracontrolo.com/products/ultravac-clp)

Reviewed: 2026-10-22. Ultra Controlo engineering. https://library.ultracontrolo.com/answers/how-much-ventilation-does-a-medical-air-or-vacuum-plant-room-need/