INCREASE AIR FLOW / VENTILATION
During summer months, opening windows massively increases the quality of your indoor air. It allows healthy ventilation and circulation of fresh air, lowering risk of dust mites, mould, etc. Reducing humidity in the property through this kind of ventilation actually makes the property feel warmer, even at a colder temperature.
During winter months however, you don’t want to be letting damp/moist air into the home. A simple rule of thumb is that if you couldn’t dry your clothes outside, don’t open the windows. A combination of trickle vents, extractor fans and de-humidifiers is absolutely necessary.