Our natural ventilation built-in window system ‘Brewell 300’ is a product that allows ventilation without actually opening the window. You want to open the window when you’re cooking or vacuuming, but when it’s raining or snowing, it’s not that easy. But with our product, ventilation is possible in any weather, even when there’s smog. ‘Brewell 300′ uses less energy than ordinary air purifiers or ventilation ducts, and is applied to window frames allowing a better view. The special filters allow fresh air even in harsh weathers, satisfying the basic feature windows have ventilation. The built-in filter in the window frame creates a luxurious interior design and is easily operated with just a switch. In case of electrical discharges or personal preferences, manual control is easily possible by using the adjustable stick. The exterior part of the ventilation has an awning to prevent rain or snow inflow, and also has a net to prevent insects.’Brewell 300’ is a product that cares for our health and makes our windows beautiful.