HEAT PUMP INSTALLATION IN ORANGE COUNTY AND CARLSBAD

The Department of Energy says heat pumps use electricity to transfer heat rather than generate heat. In the cooling season, a heat pump moves heat from inside your home to the outdoors. In the heating season, it moves heat from the outside air into your home. That is why one system can replace both an air conditioner and a furnace.

ENERGY STAR describes two common forms. A ducted air-source heat pump can connect to the forced-air ductwork found in most homes. A ductless (mini split) heat pump does not need ductwork: one or more head units mount on an interior wall or ceiling and connect to an outdoor unit.

• U.S. Department of Energy, Energy Saver: Heat Pump Systems (opens in a new tab)
• ENERGY STAR: Air-Source Heat Pumps (opens in a new tab)
• ENERGY STAR: Ductless Heating & Cooling (opens in a new tab)

The Department of Energy describes heat pumps as an energy-efficient alternative to furnaces and air conditioners for all climates. A heat pump heats and cools with one outdoor unit and suits Southern California's mild winters, and many homes are good candidates. We compare it with an AC and furnace setup for your house.

Your address still matters. NOAA explains that the marine layer forms when cold ocean water cools the air above it, and the National Weather Service in San Diego says the weather can be very different between beaches and inland areas. A home near the water and a home farther inland can ask different things of the same system, so we size from the house rather than the city.

• U.S. Department of Energy, Energy Saver: Heat Pump Systems (opens in a new tab)
• NOAA JetStream: The Marine Layer (opens in a new tab)
• National Weather Service San Diego: The Weather Guide, 6th Edition, 2012 (PDF) (opens in a new tab)

An AC and furnace are two pieces of equipment, one to cool and one to heat. A heat pump does both. ENERGY STAR says that in most zones an air-source heat pump can be installed as a drop-in replacement when a central air conditioner or furnace needs replacing, but your ducts and electrical panel still need to be checked first. The Department of Energy also describes hybrid systems that pair a heat pump with a gas furnace.

Our full comparison is in the guide linked below this section. It covers how each option works, the sizing question and what to ask any contractor.

The Department of Energy calls mini splits an efficient and flexible solution for homes without existing ductwork, and says they are generally the best retrofit option for those homes. Where ducts already exist, a ducted heat pump can use them if they are in good shape. At the assessment we look at your ducts and compare both options for your house.

• U.S. Department of Energy, Energy Saver: Heat Pump Systems (opens in a new tab)
• ENERGY STAR: Air-Source Heat Pumps (opens in a new tab)
• ENERGY STAR: Ductless Heating & Cooling (opens in a new tab)

Wherever you live, the same state rules shape a heat pump changeout. CSLB's HVAC checklist tells homeowners to make sure the contractor obtains a building permit and that the building department performs all required inspections. The California Energy Commission's 2025 Energy Code, which applies to buildings whose permit applications are applied for on or after January 1, 2026, adds testing to the permit.

• Duct sealing and verification: the Energy Commission says replacing the outdoor unit or the indoor unit of a split system, by itself, triggers duct sealing and field verification. An independent rater, called an ECC-Rater, verifies the result.
• Refrigerant charge: the Commission's compliance manual calls for refrigerant charge verification on heat pumps in all climate zones. For air conditioners it applies in climate zones 2 and 8 through 15.

Which tests apply depends on the equipment and your address. We do not assign climate zones to cities, so ask your contractor or building department which zone your address is in and which of these tests apply.

• CSLB: HVAC Installation Fact Sheets and HVAC Checklist for consumers (PDF) (opens in a new tab)
• California Energy Commission: 2025 Building Energy Efficiency Standards (opens in a new tab)
• California Energy Commission: 2025 Single-Family Heating, Ventilation, and Air Conditioning (HVAC) (opens in a new tab)
• California Energy Commission: 2025 Single-Family Residential Compliance Manual, Chapter 9 (alterations and repairs to existing homes) (opens in a new tab)

If your home is in a homeowners association that requires approval for physical changes, Civil Code Section 4765 sets the ground rules for that review: the association's decision is to be in writing, and a disapproval has to explain why and describe how to ask for reconsideration. HOA approval and a city permit are separate. One does not replace the other.

An outdoor unit and its refrigerant lines can show from outside the house, so ask your association for its rules before the schedule is set, and give the association and the city the same drawings.