Serving San Anselmo and Marin 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 San Anselmo 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. Marin County homeowners whose AC systems are approaching the 10 to 15 year mark should factor refrigerant transition costs into their repair-versus-replace analysis.
Marin County's marine climate creates HVAC conditions that are mild in temperature but persistent in humidity and, for coastal installations, corrosive from salt air exposure. Condenser coil degradation in San Anselmo is measurable over 3 to 5 years without protective maintenance.
San Anselmo sees approximately 400 cooling degree days in summer and 5,400 heating degree days in winter, with real seasonal demand on both systems. Marin County homes built around 1975 — the local median — are at the age where original HVAC equipment is entering the replacement planning window.