Sharing an air conditioner with another room can be a bit challenging, especially if the only way for air to pass between the rooms is through the gap between the ceiling and the wall. However, it's not impossible. Here are a few steps you can take to improve air circulation and share the cool air between the two rooms:
Use Fans: Place fans strategically to help push the cool air from the air-conditioned room into the adjacent room. Oscillating fans or box fans can be effective in improving air circulation.
Seal Any Leaks: Check for any gaps or leaks around doors and windows in both rooms. Seal them properly to minimize air leakage and improve cooling efficiency.
Create Ventilation Openings: If possible, you can create ventilation openings near the ceiling or the top part of the wall to allow air to flow more easily between the rooms. This might involve installing vents or grilles.
Use a Portable Air Conditioner: Consider using a portable air conditioner that can be moved between the two rooms as needed. These units come with exhaust hoses that can be extended to fit through a partially open window or vent.
Vent Extender: Use a vent extender to direct the cool air from the air conditioner further into the adjacent room. Vent extenders can be found in hardware stores and are designed to fit over standard air vents.
Drapes or Curtains: Hang heavy drapes or curtains to separate the rooms and prevent the cool air from escaping through the gap.
Fans on the Window: If there's a gap between the window and the window frame, you can use window fans to draw in cool air from the air-conditioned room and push it into the adjacent room.
Remember that while these methods can help improve air circulation, they may not be as effective as having a dedicated air conditioner in each room. The effectiveness of sharing the air conditioner will depend on the size of the rooms, the power of the air conditioner, and the insulation of the rooms.
If it's possible and within your budget, consider installing a separate air conditioner for the other room to ensure optimal comfort for both spaces. Alternatively, you can consult with a professional HVAC technician to explore other options based on the specific layout and conditions of your rooms.