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Ductwork cleanliness standards with M1 classification

m1 cleanliness classification

It is hard to overestimate the cleanliness . Especially nowadays, when alarms go off about air full of pollution like particle matter, hydrocarbons or Carbon and Sulphur oxides. Legislators are trying to lower the discharge of harmful elements with laws and directives and citizens are using more and more complex air filters. How about we could take care of clean ventilation from the beginning?

Along with this assumption, Building Information Foundation RTS was established in Finland. Its main objective is cleanliness classification of air-handling components. Although that the participation is voluntary, it’s become a standard in Finland HVAC industry. Among many certifications present on the European and worldwide market, this one is particularly interesting since it’s directly linked to air quality in air-handling systems. This is why ALNOR has joined the program and as a result, was received an M1 Cleanliness Certificate in October 2017. General requirements for classified components are:
• a classified component shall not increase the concentration of contaminants that are detrimental to health or comfort in the air handling system or supply air
• a classified component shall not produce odours or gaseous or particulate contaminants that decrease the quality of supply air
• a classified component shall be easy to clean

After our samples were tested in the University of Eastern Finland and during an audit in our premises, where randomly selected components from the assembly line and warehouse was checked, we were given a report led to the conclusion that ALNOR’s production process meets strict and demanding requirements of RTS.
M1 Cleanliness Certificate includes Spiral round ducts Z275, pressed and segmented bends and fittings and also dampers and is valid for 3 years. The period can be obviously extended, provided no significant changes in the production technology were made. Current information about valid certificates is published on

The cleanliness class M1

The cleanliness class M1 certificates for Z275 circular ducts, fittings and dampers.

To avoid the pollution of the product after they leave our warehouse, ducts are fitted with plastic end caps while fittings are shipped inside sealed cardboard boxes.  

Spiral ducts class M1

Z275 spiral ducts with plastic end caps- ready for dispatch.

Certyfikaty klasy M1


Download M1 cleanliness certificates
PDF file »