Do you know the hygiene regulations for ventilation systems?

Do you know the requirements regarding the hygiene of ventilation systems of each of the applicable regulations? Below, we explain the requirements of the Technical Code for Building, the Regulations for Thermal Installations in Buildings (RITE, 2007), and the relevant UNE standards (UNE-EN 13403:2003, UNE 100030 IN:2005, UNE-ENV 12097, UNE 100012:2005).

Ventilation regulations

The regulations establish that all components of the ventilation equipment “must be accessible for cleaning, disinfection, maintenance, and repair or replacement.” Additionally, it stipulates that the interior finish of the ducts must withstand aggressive operations of disinfecting products and provide mechanical resistance so that it can endure the stresses arising from mechanical cleaning operations.

What danger lurks inside your ventilation system?

Aware of the undesirable proliferation of microbial agents that can occur in the ducts of the ventilation system, the regulations stipulate that “the materials used should not facilitate (or be nutrients for) microbial proliferation. Additionally, all types of materials used in the insulation boards must meet specific requirements after having been exposed to twenty cleaning simulations.”

The accumulation of dirt or water inside the ducts of the ventilation system is among the causes of the proliferation of microorganisms, especially legionella. Therefore, it is of utmost importance that the system has smooth ducts (and to the extent possible, antibacterial and anti-static) to prevent the accumulation of dust and dirt inside (a breeding ground for microbial contamination). Furthermore, to prevent the growth of microorganisms, the standard emphasizes the importance of rounding the corners of the ducts (in the case of being rectangular) to facilitate cleaning operations.

Hygiene

The applicable regulations outline different hygiene methods to carry out the necessary cleaning actions: vacuuming, using compressed air (pressurized air), and brushing (metal brushes should be avoided). It must be considered that the plates must be prepared to withstand cleaning actions corresponding to a useful life span of two decades (one annually) without suffering any damage (peeling, flaking, eroded material, and delamination of the material).

Evaluation or review of the ATUs (air treatment units) and the ducts of the ventilation systems

For the evaluation or review of the ATUs and the ducts, the following requirements are established:

For air treatment units:

• Industrial, residential, offices, restaurants, and commercial: 1 year
• Health and special use buildings: 6 months

For the duct network:

• Industrial, offices, health buildings and specific use, and restaurants: 1 year
• Residential and commercial: 2 years

The CTE, for its part, establishes that the intake ducts, in addition to having an interior finish that prevents the accumulation of dust and dirt, must be practicable for their hygiene at a maximum every 10 meters. Regarding the extraction ducts, these “must have a finish that hinders their soiling and must be practicable for inspection and cleaning at the crown and at the start.”

The maintenance operations stipulated by the CTE are the following:

• Cleaning of ducts, openings, and filters: 1 year
• Verification of the tightness of the ducts: 5 years
• Inspection of the condition of the filters: 6 months