Serving Dunkirk and Calvert County
R-410A refrigerant — the standard in residential AC systems installed from the mid-2000s through 2024 — is being phased out under EPA regulations, with new systems now required to use lower-GWP refrigerants like R-454B. For Dunkirk homeowners with existing R-410A systems, this creates a planning consideration: refrigerant availability and pricing for older systems will change over the next several years. Calvert County homeowners whose AC systems are approaching the 10 to 15 year mark should factor refrigerant transition costs into their repair-versus-replace analysis.
Calvert County sees real demand from both heating and cooling systems across the year. Furnaces carry the load through winter, AC systems take over from late spring through early fall, and the shoulder seasons are the right time to service each before peak demand arrives.
Dunkirk sees approximately 2,490 cooling degree days in summer and 4,130 heating degree days in winter, with real seasonal demand on both systems. Calvert County homes built around 1968 — the local median — are at the age where original HVAC equipment is entering the replacement planning window.