"affectionate air" is correct and usable in written English.
You can use it to describe a situation where a person is being affectionate towards another person. For example: "He spoke with an affectionate air as they shared a tender moment."
Walker's long-widowed mother, Amy Field, a tall and elegant figure with an air of affectionate reserve, if that is possible, lived in the city but came out to Snedens Landing on birthdays and holidays.
With an air of affectionate poignancy, he points out that each of his images, rendered as a jpeg, is about 5mb in size – larger than any file that the individual computers could sustain.
Hacking smokers' coughs, glass clinks and a thousand affectionate "youse cunts" punctuate the air.
The explicitly politicised, late-1960s countercultural Brazilian protest movement gets an airing through this affectionate, if somewhat genuflecting documentary.
She waved and gave her horse High Kingdom an affectionate slap, but there was no punch of the air.
Blanche wrote an affectionate burlesque of the young man who had "the air of a girl in pajamas" and preached social revolution "at the Splendide, before a very cold magnum of champagne".
Ivy was affectionate, exuberant, and highly competent; at times, though, she had the air of an abandoned child.
She returned every year to Oxford; a stream of blue air letters from Iris continued for the next 20 years, always affectionate, always concerned.
He can go against the grain of civil or decent respectful conversation, seducing many with the sound and air of "Fuggedaboutit" that has become a familiar and affectionate signage on the way out of Brooklyn to Staten Island.
In the wider world Lineker remains almost unanimously popular, a kind of groovy uncle whose private life has been aired in the tabloid press, albeit in an affectionate way, a sedate kind of domestic shemozzle.
