the biggest savings I ever got on my power bill was when I replaced the 1987 Trane air conditioning condenser and air handler with a 2018 unit. cut my power bill in half. my current downsized house has a 2003 Trane system. avg power bill for house and shop (also air conditioned) is about $115.00 a month. the 3 hottest months I'm about 140.00. gulf coast of florida.
)
)