Hot and dry climate
HVAC services in California
California spans coastal fog to desert heat, and Title 24 rules mean most HVAC changeouts need a permit and duct testing.
- ZIP codes covered
- 2,077
- Cities and towns
- 830
Heating and cooling in California
Extreme summer heat with low humidity. Systems are sized for very high outdoor temperatures, dust loads coils and filters, and evaporative coolers still serve many older homes.
California's Title 24 energy code applies to most HVAC replacements. Alterations commonly require a permit, duct leakage testing and verification by a certified HERS rater, so a quote that skips the permit is a red flag.
Climate varies more than anywhere else in the country. Coastal San Diego and Los Angeles homes often had no central AC; inland valleys like the San Fernando Valley, Inland Empire and Sacramento routinely pass 100°F. Heat pumps are the most common upgrade, often as ductless systems in older homes.
HVAC contractors in California need a C-20 (warm-air heating, ventilating and air-conditioning) license from the Contractors State License Board for most jobs over the minor-work threshold. You can look up any license on the CSLB website.
Most common needs in a hot and dry climate
- AC capacity at 100°F+
- Coil and filter cleaning from dust
- Rooftop and attic unit service
- Heat pump heating for mild winters
California city guides
Local details on housing, utilities and permits.
Los Angeles, CALos Angeles cooling needs change dramatically from the coast to the valleys. Westside homes may get by with little AC, while the San Fernando Valley regularly passes 100°F. Much of the city's housing predates central air, so wall furnaces, floor furnaces and add-on systems are common.San Diego, CASan Diego is known for mild weather, but heat waves have pushed many homeowners to add cooling. Coastal homes often have only a furnace, while inland neighborhoods and East County see real summer heat.Sacramento, CASacramento summers regularly top 100°F, cooled at night by the Delta breeze, and winters are cool and foggy. Central AC and gas furnaces are standard, with heat pumps an increasingly common replacement.San Jose, CASan Jose has warm, dry summers and mild winters, but inland heat waves regularly push past 95°F. Much of the city was built from the 1950s to the 1970s, including Eichler homes with radiant heat in the slab and no attic for ductwork.Fresno, CAFresno summers are long and very hot, with many days over 100°F, and the San Joaquin Valley traps smoke and dust. Air conditioning is a necessity, and heat pumps have become the standard replacement for older gas furnaces and AC.San Francisco, CASan Francisco's cool, foggy climate meant most homes were built with heat but no air conditioning. Victorians, Edwardians and 1930s–50s row houses often have gravity furnaces, floor furnaces or wall heaters, and heat pumps are now the main upgrade.Long Beach, CALong Beach's coastal climate is mild, but heat waves inland and salt air near the water shape its HVAC work. Many older homes have only a wall or floor furnace, and heat pumps and mini-splits are the common way to add cooling.Pasadena, CAPasadena sits at the foot of the San Gabriel Mountains, with hot, dry summers and mild winters. Its Craftsman bungalows and Spanish Revival homes often have older furnaces and limited duct space, and the January 2025 Eaton Fire in neighboring Altadena left smoke and ash in many homes.Riverside, CARiverside is an Inland Empire city with hot, dry summers that regularly pass 100°F. Central AC is essential, and heat pumps are the common replacement for older gas furnaces and AC.Stockton, CAStockton sits at the edge of the Sacramento–San Joaquin Delta, with hot, dry summers cooled at night by the Delta breeze and foggy winters. Central AC is essential, and heat pumps have become the common replacement for gas furnaces.Anaheim, CAAnaheim is hotter than coastal Orange County, with summer highs regularly in the 90s and dry Santa Ana winds in fall. Anaheim Hills borders wildland, and smoke and ash from canyon fires affect homes across the city.Santa Barbara, CASanta Barbara's mild coastal climate means many homes were built without air conditioning. Heat pumps and ductless systems are the common upgrade, and sundowner winds and wildfires, like the 2017 Thomas Fire, bring heat and smoke.Oakland, CAOakland's mild climate meant most older homes were built with a furnace and no air conditioning. Heat waves and wildfire smoke have changed that, and heat pumps are now the standard way to replace old furnaces and add cooling at the same time.Bakersfield, CABakersfield has some of the hottest summers in California, with many days above 100°F, and the southern San Joaquin Valley regularly ranks among the most polluted air basins in the country. Reliable cooling and good filtration both matter here.Irvine, CAIrvine is a master-planned city of villages built mostly from the 1970s on, with mild weather, warm summers and HOA rules that shape where equipment can go. Many original systems are now on their second or third replacement.Chula Vista, CAChula Vista stretches from the bay to the eastern hills, and its climate changes with it: mild near the water and noticeably hotter in eastern neighborhoods. Many western homes have only a furnace, while newer eastern homes have central AC.Modesto, CAModesto has hot, dry Central Valley summers and cool, foggy winters. Central AC is essential, and heat pumps are increasingly replacing gas furnaces and old AC at the same time.Santa Ana, CASanta Ana is one of Orange County's oldest and densest cities, with historic neighborhoods, post-war tract homes and dry Santa Ana wind events in fall. Many older homes have wall furnaces and no central air, so heat pumps and ductless systems are common upgrades.San Bernardino, CASan Bernardino sits at the foot of the San Bernardino Mountains, with hot summers that regularly pass 100°F, dry Santa Ana winds and wildfire smoke from the foothills. Central AC is essential, and heat pumps are a common replacement.Berkeley, CABerkeley's mild climate meant most homes were built with a furnace and no air conditioning. Heat pumps are now the standard upgrade, and the city's energy rules encourage efficient equipment when homes are sold or renovated.Santa Monica, CASanta Monica's ocean breezes keep it cooler than most of Los Angeles, and many homes and apartments were built without air conditioning. Salt air shortens the life of outdoor equipment, and heat pumps are the common upgrade.
More covered areas in California
Contractors also take calls in these communities, among many others. Check your ZIP above to confirm.
- Glendale · Los Angeles Co.
- Van Nuys · Los Angeles Co.
- Burbank · Los Angeles Co.
- Inglewood · Los Angeles Co.
- North Hollywood · Los Angeles Co.
- Orange · Orange Co.
- Torrance · Los Angeles Co.
- Whittier · Los Angeles Co.
- Concord · Contra Costa Co.
- Fullerton · Orange Co.
- Ventura · Ventura Co.
- Oxnard · Ventura Co.
- Moreno Valley · Riverside Co.
- Oceanside · San Diego Co.
- Garden Grove · Orange Co.
- Corona · Riverside Co.
- Hayward · Alameda Co.
- Escondido · San Diego Co.
- Santa Clara · Santa Clara Co.
HVAC services available in California
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