Air Conditioner

This is almost always due to the system being low on A/C refrigerant. You should have the system checked for leaks, repair any leaks then have the system recharged. It may be a very slow leak, and in this case they might not find any leaks. In this case, have it recharged and make sure the shop adds dye to the refrigerant. This dye is used to help find slow leaks, most good shops should have this product.