Vinyl-Lite Greenhouse Windows and Mini-Solariums are engineered to be energy efficient. The fusion welded frames, in combination with weather seals, double glazing, and an insulated base, keep out the cold winter winds. In the warmer months, the top and side venting windows open wide to provide a cooling breeze. This is the only garden window engineered to be a garden window; all others are a mix of various style windows screwed and glued together.