Ventilation with the sun
In 2008, we were refurbishing our house and have also installed a solar ventilation system on the facade at the same time which we haven't regretted since. There is always fresh air indoors and we appreciate the warmth which is provided by the sun, especially during spring and autumn. Our daughter and her husband who are living upstairs were very sceptical at the beginning and didn't want to have such a system.
But they have noticed the difference between our solar ventilated room and their room very quickly and so they have changed their opinion after a short time and also wanted to have such a "solar thing". After my husband had already installed the first system downstairs by himself, it was not very difficult to install a second one upstairs. Now even our son is convinced of this useful system.