Last summer we had Priority Air come and evaluate our air-conditioning unit. We purchased a package, that included an inspection, cleaning, a new thermostat, new filter, duct cleaning, and inspections for the next 3 years for about $700. Even though we have a very old a/c unit, because of their work our power bill was reduced! They did a good job at explaining their services, and they showed up at the time they said that they were going to come. My only complaint is that they told us that they would be calling us every year to schedule our yearly inspection, but we had to call them this summer. A good company.