The size of your air conditioning unit must be compatible with your ductwork. The wrong sized ducts will cause similar problems to having an improperly sized AC unit for your square footage.

Central air conditioning A true central air conditioning system uses ducts to distribute cooled air throughout the house. In a “split system,” the most common design, refrigerant circulates ...

How to install your portable air conditioner 1. Choose a location near a window and outlet. Your portable AC needs several feet of unobstructed floor space so it receives adequate airflow.

It's also worth asking them to check the ductwork, especially if your cooling bills have been higher than normal. Up to 30 to 40 percent of energy can escape through leaky or uninsulated ducts.