5x5 grow in outside shed

HI people , need some advice , I live in an area it seems where the humidity is high , it's 70% today , my only growing area is an outside brick shed with a pvc door and old style corigated roof , it's reading 99% on the humidity meter , Not good conditions I'm going to be using 5x5 tent with a air cooled 1000w hood , 4 plants - 25 litre air pots using the Scrog method, because my environment is dodgy as fk I need to have a good set up to avoid problems My Q is what size fans filters r needed and don't mind if I got to spend money either what other equipment can I buy to properly keep my grow environment in a good state , thanks for any advice

a dehumidifier asap
ac

Yep ac works like a dehumidifier by itself but coupled with an actual dehumidifier it would get you down to the 65%range running constantly. In the cold months get a good propane heater for heat humidity and co2. Remember to ventilated before entering.