If you have a small box with a glass top and want to keep the inside as cool as possible under the sun without an AC system, here are a few suggestions:
Reflective or Light-Colored Surface: Use reflective or light-colored materials for the box's interior. This will help reflect sunlight and reduce heat absorption. Consider using materials like aluminum foil or white paint to cover the inside surfaces of the box.
Insulation: Insulate the box to minimize heat transfer. You can line the walls with insulating materials such as foam or bubble wrap. Insulation helps to reduce heat gain from the surrounding environment.
Ventilation: Create proper ventilation to allow hot air to escape and promote airflow. You can install small vents on the sides or back of the box to let hot air exit. Place the vents near the top of the box to encourage rising hot air to escape.
Shade the Box: Shield the box from direct sunlight by placing it in a shaded area or using umbrellas, awnings, or any other form of sunshade. Blocking direct sunlight can significantly reduce heat buildup.
Solar Reflective Film or Shade Cloth: Apply solar reflective film or attach shade cloth to the exterior of the glass top. These materials can help reflect sunlight and reduce the amount of heat transmitted into the box.
Use Ice or Cooling Elements: Place a container of ice or cooling elements inside the box. This can help lower the temperature and create a cooling effect. You can also consider using a small fan or a battery-powered portable fan to circulate the air around the cooling elements.
Remember, these techniques can help reduce the heat inside the box, but they may not achieve the same level of cooling as an air conditioning system. It's essential to regularly monitor the temperature inside the box, especially in extremely hot conditions, and take appropriate measures to ensure the safety of any contents within.