Dehumidifiers

If you get it well sealed it may run less once its pulled the water out the walls and floor. The alternative is to only run it when really needed and up the natural ventillation a lot.

I really only run it in the winter. I have a remote humidity meter here in the house office and the garage sort of keep in line with the house here. But I will take you advise and up it to 60% when I start using it again. incidentally the garage is a new build with double wall and Thermolites on the inside plus 150mm fluffy stuff in between.

I have one of these in my conservatory and it seems to work a treat.
Best if you can use the auto drain though tank is small.

https://www.screwfix.com/p/blyss-wdh-316db-16ltr-dehumidifier/368gy