Advice on an air purifier?

[Guest guest]

Until my landlord begins to remediate the mold situation I thought I'd

try to improve our symptoms with and air purifier. I just bought a UV-C

purifier and want to give it a go. I've been leaving all the windows

open even at night to try to exchange the air. Should I still leave the

windows open or would shutting the house provide better results. Up to

this point keeping the house shut for the night )even if I open first

thing in the morning) makes our symptoms much more severe.

Thanks,

Moneca