Yes, you can keep a window unit air conditioner running all day and night without opening the windows. Window unit air conditioners are designed to be standalone cooling systems that do not require any external ventilation, unlike central air conditioning systems.
Window AC units are self-contained, meaning they draw in warm air from the room, cool it through the refrigeration process, and then expel the cooled air back into the room. The warm air and heat generated during the cooling process are exhausted outside through the back of the unit. Therefore, there is no need to open the windows when using a window AC unit.
However, there are a few considerations you should keep in mind:
Energy Efficiency: Running an air conditioner continuously for long periods can increase your electricity bills. It's essential to set the thermostat at a comfortable temperature and consider using a programmable timer to turn off the AC when you don't need it, such as when you're away or asleep.
Maintenance: Regularly clean or replace the air filter to ensure the unit operates efficiently and to maintain good indoor air quality. Also, keep the area around the AC unit clear of obstructions to allow proper airflow.
Room Size and Cooling Capacity: Make sure your window AC unit is appropriately sized for the room you want to cool. An undersized unit will struggle to cool the space adequately, while an oversized unit may lead to excessive energy consumption and inconsistent cooling.
Safety: Always follow the manufacturer's instructions and safety guidelines when using any electrical appliance, including window AC units. Avoid overloading electrical circuits, and make sure the power cord and plug are in good condition.
If you have concerns about running the AC unit all day and night, you might consider using it in combination with other cooling methods like fans or utilizing it during the hottest parts of the day to maximize energy efficiency.