Use a Timer: If you have a timer on your air conditioner set it to turn off when you leave and then to turn back on a couple minutes before you return to your house. This saves the air conditioner from working while you aren’t home therefore saving you money and energy.

Seal the Unit: Once a room air conditioner is in place, seal the space around it with rope caulk or some other sealant to prevent warm outside air from leaking in.

Close the Fresh-Air Vent: Make sure the fresh-air vent is closed when the room air conditioner is operating so you aren’t cooling outside air. Open the vent when the outside air is cooler to let in fresh air.

Use Fans With Your Air Conditioner: Fans are a great way to circulate air around your room. You can use a fan to spread the cool air that your air conditioner is creating so that the room cools down faster.

Maintain the Furnace: Clean your furnace filters monthly or replace if necessary. A clean unit runs more efficiently.