Installation Overview

ARA FirePASS systems have a smaller footprint compared to conventional gaseous suppression systems and do not require rigid piping within the protected spaces. The only requirement is simple, minimal pressure piping to each protected area and to the ambient air, along with wiring of the oxygen monitoring units in the protected areas.

It is recommended that protected areas be equipped with highly sensitive smoke detectors such as VESDA or equivalent. This is to ensure that any smouldering combustion from cable faults, for example, is reported in its incipient stages.

A comfortable, breathable atmosphere is created inside the protected space by the ongoing  ventilation with fresh hypoxic air.

The highly reliable hypoxic air generators require very little maintenance – a maintenance cycle of 6 months is typical. Regular monthly inspections are recommended to ensure a fire preventative atmosphere is maintained.

ARA FirePASS systems can be implemented  as an alternative, but also as a complementary or supplementary option which enhances the conventional fire-safety means without interfering with their performance.

Note: The protected areas have to be well sealed in order to minimize the permanent leakage of air in and out of the room. All spaces in the protected area must have split-type air cooling or closed, dedicated air recirculation systems.

Preparatory Work

Sealing the rooms
The key factor relating to running costs (energy consumption and maintenance) of an installation of ARA FirePASS fire prevention systems, is the leakage. This is the sum of permanent leakage of the protected area and the temporary leakage created by door openings. Investing in improving the sealing of the protected areas will have a  direct impact on running costs as they are directly proportional to the leakage rate achieved. The payback for such improvements typically, is less than one year.

To evaluate the current leakage of the area to be protected, we recommend performing an integrity fan test prior to any works being commenced.

Venting / Cooling

The area where the compressors and filtration units are housed is required to be well-vented in order to allow a permanent supply of fresh, ambient air to the compressors. Alternatively, the room can be cooled with chillers but this will also require a supply of fresh air.

There is a requirement for a small drain in the machine room for the wastewater of the condensate cleaner.

Note: The final design of the machine room (the manner in which it is being cooled/vented) has to be agreed jointly. Separate recommendations will be given regarding all preparatory work. Material and diameters of tubing/piping mentioned in the following sections are to be verified, based on the final design.

Installing the System

ARA FirePASS systems come readily mounted and tested. Once on site, the system is connected to the room sensors and to the power supply. The system is then connected to the rooms via the installed tubing. The by product oxygen-enriched air is vented outside.

The power supply for the compressors is 400 Volts/50 Hz/3-phase with slow fuses to serve the compressors. The generator units need 220Volts/50 Hz and shall be buffered via the central UPS.

Tubing to the protected area
Supply of the protected area with hypoxic air can be achieved either with metallic, PVC, PA, ABS or similar material tubes or pipes. If the piping for the provision of hypoxic air to the protected area crosses other fire sections, it shall be acheived with steel piping.

The tubes or pipes shall be installed in a way that they build the shortest possible connection to the room and have as few bends as possible. For the piping to the protected area, the sufficient inner diameter will depend on the length and number of bends (generally, 11 mm for all areas, with two tubes or pipes in parallel for the supply of the bigger area). The installation of tubing or piping is to be planned, prepared and carried out by certified installers.

Noise generated at the air outlets is reduced by installing sound mufflers.


Piping for the oxygen enriched air outlet may be done with a PVC, PPS, ABS or similar pipe, or with a metal duct. It is to lead directly outside the building, ideally up to the roof level, to avoid any increase of the danger of fire.

A sufficient inner diameter will be approximately 10-12mm, depending on the location of the protected area and the respective distance and number of bends required.

The installation of the piping is to be planned, prepared and carried out by certified installers.

Note: The oxygen enriched airflow has to be vented outside the protected area whilst the system is operating, as this waste flow will carry up to 35% oxygen content.

Wiring the Room’s Oxygen Sensors

Each room is to be equipped with two Oxygen Monitoring Units as a minimum. The monitoring units are typically placed at eye level, at an appropriate distance from the door of the room. This is to provide for monitoring of oxygen conditions and alert if doors are wedged open or not closed properly, whilst minimising the amount of false high oxygen alarms. Each sensor is to be wired directly to the ARA FirePASS control panel with its own 7-wire, fire rated shielded cable


The ARA FirePASS hypoxic air generators are highly reliable passive units that can operate for decades with proper maintenance. This normally includes, as a minimum, changing the filters after every 3,000 operating hours or at latest after 12 months. This cycle applies if the supplied fresh air is compliant with the required quality. If the air quality is lower (in the event of dust, humidity, temperature etc.) the cycle of filter changes needs to be reduced.

The compressors require regular maintenance with a cycle of 2,000 running hours. We recommend a maintenance cycle of 2,000 hours for the whole system (both for compressors and generators).


Acceptance test
The operator/operating company must subject the ARA FirePASS oxygen-reduction system to an acceptance test by a qualified person after installation or after any significant modification to the system. This test must take place prior to commissioning.

Regular Inspections
The operators /operating company must have the proper function of the ARA FirePASS oxygen-reduction systems tested by a qualified person at least once per year. Special operational circumstances may make it necessary to carry out more frequent inspections.

Record of Inspections
The results of the inspections must be recorded in an inspection report. The records of the acceptance tests must be kept throughout the operating time of the ARA FirePASS oxygen-reduction system. The records of the regular inspections must be kept for at least 4 years. These may be stored on computer data carriers. These documents must be presented to the competent supervisory authorities upon request.


The ARA FirePASS hypoxic air generator systems come with a regular warranty of two years. The warranty commences on the date of delivery.


  • Damage caused by using compressed air, not following the specifications, is not covered. This includes too high or too low pressure, wet air and air with high oil content etc.
  • Maintenance is to be carried out per the times outlined in the manual
  • Warranty does not cover consumables (filter elements and activated carbon refill)
  • Warranty applies to parts only
  • Damage caused due to excessive leakage resulting in high duty cycles is not covered