Testing and maintenance of ventilation systems

June 6, 2023
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Unkategorisiert

Basically, a ventilation system has the core task of supplying closed rooms with fresh air and transporting stale air to the outside. For optimum room utilization, it is necessary to create the required temperature, humidity and oxygen content.

Especially in times of increasing energy awareness, the installation and operation of ventilation systems continues to gain ground. Thanks to the possibility of controlled energy recovery from the exhaust air, the use of these systems is more than sensible from an energy point of view.

However, in order to make optimum use of all the advantages of a system, to minimize hazards (e.g. health and fire risks) and to comply with legal requirements in the long term, the proper condition must be ensured through regular inspections, maintenance and tests.

Why does a ventilation system need to be inspected and maintained?
During operation of the system, the air flowing into the room is conditioned (heated, cooled, dehumidified or humidified, filtered) and distributed in such a way that there is no health risk for the people in the room (e.g. due to draughts, mold spores, lack of oxygen, excessive temperature and humidity, etc.) or that hygienic ventilation conditions prevail. In the course of inspection, maintenance and testing, it is checked whether the required values and conditions are achieved and whether there are any defects or risks.

Practical tips
To detect faults and damage to ventilation systems in good time, they should be inspected regularly – paying particular attention to the following points

Damage to the system components (ducts, outlets, V-belts, etc.)
Hydr. Leaks (heating or cooling coil, humidifier, etc.)
Cleanliness of filters, fans, duct walls, air outlets, etc.
Air resistance of the filters (pressure difference between before and after the filter)
Unusual noises from the system (e.g. due to a damaged motor or fan bearing, damaged or dirty fan, broken V-belt, etc.).

What is part of the system?
The main components of a ventilation system are

Ventilation duct (round or square – with insulation on the outside air side) and outlets
Fan motor + fan (radial, axial or tangential fan)
Heat exchanger (for heat recovery – usually cross plates or rotation)
Heating or cooling coil
Humidification register (spray or steam humidification)
Filters (mostly pocket filters for outside and exhaust air)
Silencer
Throttle or multileaf dampers
Volume flow controller
Fire dampers

What are the obligations when operating ventilation systems?
In Austria, the requirements of the Employee Protection Act (§22 ASchG) and the Workplace Ordinance (§13 + §27 AStV) apply nationwide as a legal obligation.

The following guidelines exist for the standardized implementation and documentation of legal requirements, e.g.

the RSOE 6000 chap. 6 of the Österr. Professional Association for Ventilation Technology (ÖFR)
VDI 6022 (microbiological testing/hygiene inspection)
VDI 2052 (especially for kitchens)
ÖNORM H6031 (for fire dampers)
EN 15780 + 16798-3
the ISO 16890
ISO 14644 and EU GMP (for cleanrooms)

which can be used as a basis for proper, safe and hygienic system operation.

Further requirements(obligations) are usually also imposed by the liability insurers, which can lead to a reduction in benefits from the insurer if the operator does not fulfill them sufficiently. It is advisable to take a look at the insurer’s insurance conditions.

How often does a ventilation system need to be checked?

Ventilation systems must

after significant repairs or modifications
if there are reasonable doubts about the proper condition
regularly recurring min. 1x annually (max. every 15 months)

be checked.

How is the test carried out?
The audit is carried out by

Inspection – visual inspection for damage, soiling, wear, marking, labeling, accessibility, documentation
Testing – function of the protective and monitoring equipment, function of the safety equipment (e.g. fire dampers)
Analysis – of the system condition and cleanliness (e.g. by means of swab tests, air samples, etc.)

Who can carry out the test?
The tests may be carried out by authorized tradespeople, accredited inspection bodies, civil engineers, technical offices or qualified company employees.

What is checked?

Air volume flows (supply air / extract air, fresh air / exhaust air)
Hygiene & fire protection condition of the ventilation center
Dust surface density according to EN 15780 *.
Filter units (correct alignment, correct filter class)
Colony-forming units (mold and legionella) *
Video inspection of the air ducts at representative points
Hygiene & fire protection condition of the air duct network
Air quality (humidity, CO2 content, fine dust pollution)

How should the inspection and maintenance be documented?
Each implementation must be documented in writing for at least 3 years and filed in paper or digital form.

How is maintenance/cleaning carried out and how often is it necessary?
Ventilation systems do not have to be maintained (but checked) by law. However, it usually makes sense to carry out maintenance (cleaning), particularly from a hygiene, fire protection and business management perspective, as the

Hygienic safety (risk of illness)
Safety (fire hazard – especially with kitchen exhaust air)
Reliability (risk of downtime)
Longevity (cost risk)

is very strongly influenced by cleanliness and inspection defects are detected much more frequently if maintenance is insufficient. Maintenance is therefore the basis for a fault-free system.

The frequency and scope of maintenance depends very much on the

The requirements for indoor air quality (e.g. in clean rooms)
The period of use per day
The load (e.g. greasy steam in kitchens)
The general conditions (e.g. air intake from a busy road)

dependent.

Who is allowed to carry out maintenance?
Maintenance should be carried out by a company specializing in system cleaning (based on the legal and normative requirements) and can also be carried out as part of the inspection.

To avoid missing any more appointments in the future, download the MyBuilding24 app, where you can record all your devices requiring maintenance and manage the associated appointments, ensuring you are always on the safe side with a complete list of maintenance work available at all times.