My house was built in 1940. I have noticed the forced air pushes out a lot of dust. This is evident from lint collecting on the bathroom vanity below a vent. It only collects lint during Summer and Winter when the forced air is blowing. I change the air filter every month but there's still significant dust. How effective would it be to hire someone to clean the vents? Is there a DIY option?
I've heard the amount of dust depends on how tightly the house is built. This makes me think that with such an old home, cleaning the vents would only be a temporary fix.