What will be the best solution to supply " clean " air to the occupants in H.V.A.C. SYSTEMS other than using H.E.P.A. filters or U-V system ?

Hi! Yes, such odors are often associated with dirty air ducts. We had the same thing - after turning on the heating, we had an unpleasant odor. We decided to ask https://comfortclean.com/ for duct cleaning service and we were not mistaken with the choice of the team. The guys came quickly, made a diagnosis, and it turned out that the system had accumulated a lot of dust and even a little mold. After their cleaning, the odor completely disappeared and the air became fresh. The cost was quite reasonable.

The High Pressure Vacuum (HPV) System. This System ensures thorough cleaning of air ducts using compressed air. The pressure is regulated according to the size and type of duct, and naturally to the pollution in the duct.