If your existing AC unit is more than 15 years old, it s probably inefficient and you should consider replacing it with a newer unit. This is also true if your current system has compressor problems, or if the cost of repairs approaches the cost of a newer unit.
Heat pumps are another option to consider.
These units provide high efficiency cooling, as well as heating. As heat pump technology has developed, their reliability and popularity have increased. Many utilities in Iowa provide rebates to customers who install them. Room AC units are designed to cool one room at a time, and multiple units may be required to cool an entire house. Room ACs are a good choice if you only need to cool one or two rooms regularly, if you live in an apartment, or if you live in a small, well-insulated home.