I think you're safe with only one bird and one room.The air purifier I have covers 465 sq ft and it's in my bedroom, which is 165 sqft
I had a little hospital visit in March 2017 with an upper respiratory infection. My flock was blamed initially and I was told I'd probably have to get rid of all of them. After blood draws/testing it was found I'm allergic to dust & mold. We had an Austin in the bird room w/3 smaller table top units and another small one in the family room. So we added a Rabbit in our bedroom, a small unit in the "study" (i.e. spare room w/hubby's computer). And we can still see dander floating gently by while watching TV depending on the lighting.Thank you for your reply @SandraK.
One of our next door neighbours was (fill in the word) to have their Xmas lights installed 1 week before Thanksgiving and turned them on.I told Fred jokingly that we might have planes trying to land because they think they're @ O'Hare. I've been tempted to go outside wave at them and yell "Merry Christmas, I hope you unplug those lights before New Year's eve. Bah, Humbug!24/7, the light doesn't bother me since I wear a sleep-mask.