I tried various air purifiers and now have settled down with IQAir. Before going to bed, after vacuum cleaning the bedroom, the IQAir is turned on for almost an hour. This cleans the air. I live in a city with clean air and sleep with open window summer and winter – which here is not very cold. This and an uncluttered bedroom do seem to make easier breathing.
True, the belt had to be tightened to pay for the air purifier. However, medication is no expense. I live in Europe and pay some ten dollars a month for all my medication. It blows the mind that, spending more than any other country in ratio to population, the USA can’t provide the decency of adequate and general health care.