Not only do you need a breath of fresh air every now and then, but some plants also benefit enormously from being out in the open air. A warm sun on their green orb or the gentle breeze through their leaves are a real boost and enable them to get on with their lives indoors for a while.
Tropical plants
Most plants originate from a place far from the cold Netherlands. They grow in a warm desert or a damp rainforest. They find more or less the same warmth in our living rooms, but they lack the other advantages of living in nature. With us, it is sometimes real survival in those dry newly built houses, especially in winter. That is why being outside for a while is very nice for a tropical houseplant: a real rain shower instead of a spout from the watering can does wonders.
Rain lovers
A sprinkling or a shower can make some houseplants feel better immediately. By watering, you increase the humidity and imitate the living conditions in the tropics. Is it 15 degrees or higher outside and do you see rain on Buienradar? Then you can put plants you normally water outside. After all, they like rainwater much better than tap water.