Can the compressors take air from inside the plantroom?

ACSS ET 03/2006 asks for air taken directly from outside through filtered ducts, and HTM 02-01 requires a dedicated plantroom where other plant cannot compromise intake quality.

How high should a medical air intake be?

HTM 02-01 says a minimum of 5 m above ground level should ensure reasonable intake air quality, with extra filtration or treatment where that cannot be achieved.

Where should a medical air compressor intake be?

Q: Where should the air intake of a medical air plant be located to avoid contamination?

A medical air compressor intake should draw outdoor air away from engine exhausts, vehicle parking, chimneys and the discharges of vacuum, anaesthetic gas scavenging and ventilation systems; NHS England guidance adds that a height of at least 5 m above ground should give reasonable intake air quality.

Where should the air intake of a medical air plant be located to avoid contamination?

Medical air is made from the air around the plant, so the intake sets the starting quality. HTM 02-01 (2026), the NHS England guidance, says the cleaner the intake air, the higher the quality of the medical air produced, and that the position of the intake has a considerable effect on delivered air quality, particularly on carbon monoxide levels.

What to keep away from the intake

Internal combustion engine exhausts (HTM 02-01), and vehicle parking and vehicle access areas (ACSS ET 03/2006, Portugal).
Chimneys and waste areas (ACSS ET 03/2006).
Discharges from medical vacuum plant, anaesthetic gas scavenging systems (AGSS) and ventilation systems (HTM 02-01 and ACSS). ACSS also asks for the AGSS exhaust to be placed away from the medical air compressors and from building doors and windows.
Other plant that could compromise intake quality: HTM 02-01 puts air plant in a dedicated plantroom, not in the same room as medical vacuum or AGSS plant, and not in cylinder manifold rooms.

Height, ducting and filters

HTM 02-01 states that a minimum height of 5 m above ground level should ensure a reasonable quality of intake air; where that cannot be achieved, additional filtration or air treatment may be needed on the intake. Intakes can be ducted to reach clean air, but care is needed so that longer ducts do not restrict airflow through increased pressure drop, and manufacturers' data should confirm that compressor performance is not affected. HTM 02-01 specifies galvanised rectangular or spiral-wound ductwork, not solvent-welded PVC, and air-inlet filters immediately upstream of each compressor. ACSS ET 03/2006 likewise asks for air taken directly from outside through ducts with a filtering system, avoiding contaminated zones such as chimneys or parking.

Fire, smoke and signage

Where the compressors could draw in toxic fumes or smoke in a fire, HTM 02-01 asks for an automatic shutdown linked to local smoke detectors, whatever the intake location, with an automatic emergency cylinder manifold sited away from the fire-risk area to take over. The intake itself is signed: HTM 02-01 lists the notice "Medical air intake. Do not obstruct".

Inlet filters catch particles: the ULTRACECO SC inlet filtration goes down to 1 micron. Carbon monoxide is handled further downstream in the treatment train; the ULTRAMED station, for example, uses a catalyst filter to convert it into CO2.