THE ORDINANCE No. 3.523, OF AUGUST 28, 1998 determines the basic measures regarding the evaluation and cleaning procedures of air conditioning systems, as well as the requirement for the preparation of the Maintenance, Operation and Control Plan (PMOC) for air-conditioned environments with thermal capacity above 5 TR (15,000 kcal/h = 60,000 BTU/H).

Therefore, as air ducts are part of HVAC systems, they must be cleaned periodically to maintain good HVAC air quality.

This cleaning frequency is defined by the technician in charge. However, in some cities in the country such as Rio de Janeiro, Natal and Santos there are municipal laws determining the cleaning Yearly of the ducts.

The obligation is also determined by the new law No. 13,589, OF JANUARY 4, 2018, which reinforces the implementation of the PMOC in buildings for public and collective use, as well as the adoption of ABNT standards to ensure good indoor air quality.

Air Duct Cleaning and ABNT standards

ABNT NBR 14679 and 15848 are the norms that establish the guidelines for the execution of hygiene services and cleaning evaluation.

According to NBR 15848, the need for cleaning must occur whenever one or more cases mentioned below are found:

• mold inside the ducts;
• damp or moldy fibrous material;
• evidence of vermin contamination (traces of rodents or insects such as cockroaches and termites, which are destructive and harmful to health);
• dissemination of particulate matter from the air ducts to the indoor environment in a visible way and without the aid of equipment;
• when the ducts show evidence of a concentration greater than or equal to 7.5 g/m2 of particulate matter

If there is a need to clean the air ducts, this must be done in accordance with ABNT NBR 14679. Get in touch with Attuale Brasil, we have adequate technology for cleaning Air Conditioning Ducts.