An old window air conditioner (AC) may not be directly compatible with a sliding glass door in a new house. Window air conditioners are specifically designed to be installed in traditional windows, with the unit resting on the window sill and the accordion-like side panels filling the gaps on the sides.
However, there are alternative options you can consider to use a window AC in a space with a sliding glass door:
Sliding window kit: Some window AC units come with a sliding window installation kit or have compatible kits available separately. These kits include panels that can be adjusted to fit the width of a sliding glass door, allowing you to create a temporary seal around the AC unit.
Plexiglass or plywood: You can create a custom solution by using plexiglass or plywood to seal the gap in the sliding glass door. Cut the material to fit the opening and attach it securely to create a temporary window-like opening where you can install the window AC unit.
Portable air conditioner: Instead of using a window AC, you may consider using a portable air conditioner. Portable AC units do not require installation in a window but use a flexible exhaust hose that can be vented through a nearby window, sliding glass door, or other suitable openings.
Before attempting any modifications or alternative installations, it's important to ensure that the sliding glass door can be securely sealed, and that the chosen method does not compromise the structural integrity or safety of the door. If you're uncertain about the compatibility or installation process, it's recommended to consult with a professional HVAC technician for guidance or consider alternative cooling options suited for your specific needs.