Your Preston Heating and Cooling Experts
The federal minimum efficiency standards for new AC equipment changed in 2023, and they vary by region. Maryland falls in the southern efficiency region, meaning new AC installations in Caroline County must meet the 15 SEER2 minimum — not the 14 SEER2 that applies in northern states. Higher-efficiency equipment costs more upfront but reduces operating costs over the system's life. In Preston's climate with its extended cooling season, the payback on higher SEER2 equipment comes faster than it would in a market with a shorter AC season.
Caroline County's mixed-humid climate means both heating and cooling systems are load-bearing. An AC that underperforms in August and a furnace that struggles in January aren't unrelated problems — they're the result of the same deferred maintenance pattern that costs Preston homeowners more over time.
The combination of 1,960 annual cooling degree days and 2,750 heating degree days means Preston homeowners depend on both systems across the year. Caroline County's housing stock, with a median construction year around 1971, contains a large inventory of equipment due for evaluation or replacement.