Most systems have a lifetime of 10 to 20 years. As your equipment gets older, its efficiency can decrease dramatically.
If your unit is 7 years old or older, requires frequent repairs or stops working, fails to heat or cool areas of your home, runs excessively or constantly turns on and off, or produces high utility bills, it can be more economical
Permit requirements vary by location. Some municipalities do require a permit. If it is required, your Home Depot authorized service provider will obtain a permit during your scheduled HVAC service