Not read through the posts, but I was recommended a PIV unit as I'm getting a lot of condense in the windows. I've not had much time unit to look into it, but it lives in the loft and so say cures condensation in windows, mould and damp.
https://www.electricpoint.com/vent-axia-pureair-home-piv-479091.html?utm_source=googlebase&utm_medium=datafeed&utm_campaign=google-shopping&gclid=CjwKCAiA75itBhA6EiwAkho9e0yeVg6cB28GXwF-6n_zWk-5b3WhdAMCZZFp2dbEHh4jBeB_sNXarhoCQ1sQAvD_BwE