What Is a Ducted Heat Pump System? | Whole-Home Comfort via Ducts

If your house already has ducts from a furnace or central air conditioner, a ducted heat pump is often the most straightforward way to switch to efficient electric heating and cooling. It connects to that existing infrastructure, replacing both your furnace and AC with one system that handles all seasons. Mitsubishi describes ducted solutions as delivering efficient single-zone or whole-home comfort by integrating with existing ductwork, moving warm or cool air from one indoor unit to multiple rooms.

How a Ducted System Works

A ducted heat pump uses the same refrigeration cycle as a mini-split, but instead of blowing air from a wall-mounted cassette, it pushes conditioned air through a network of ducts. The indoor air handler pulls return air from the house, heats or cools it, and sends it back out through supply registers in each room. Because the ductwork is already in place, installation is often less disruptive than adding a mini-split system. The outdoor unit connects to the air handler via refrigerant lines, making ducted systems a standard whole-home option.

What the Installation Checklist Requires

Portland’s ducted heat pump checklist lays out best practices across the industry. The two most critical items are sizing and duct integrity.

• Sizing: Choose an inverter-driven, variable-speed heat pump sized with a heat load calculation, matching capacity as closely as possible. Oversized units short-cycle and waste energy.
• Duct leakage testing: Required for all ducted heat pump installs. Visible leaks get sealed with mastic;
• Duct insulation: Accessible ducts in unconditioned spaces like attics and crawlspaces should be repaired, sealed, and insulated to a minimum of R-8.
• Electrical: The system installs on dedicated electrical circuits.
• Outdoor unit placement: It sits on a permanent pad or level surface with clear airflow and maintenance space.
• Condensate drain: Slopes down and away from the building to a suitable termination point.
• Refrigerant lines: If flared connections are used, new flares get created with R410A tools. Manufacturer-provided tubing flares or fittings are never reused.

Startup commissioning must follow manufacturer specifications, performed by installers with manufacturer training. These requirements apply to Portland’s incentives, but they reflect what any competent installer should do.

Is Ducted or Ductless Right for Your Home?

The decision comes down to one question: do you already have ducts? If yes, a ducted system is usually the practical choice. It replaces your furnace and AC with a single unit and delivers even temperatures through rooms you already heat and cool. If your home has no ducts, ductless mini-splits avoid the cost and disruption of installing new ductwork. Ducted systems shine when the infrastructure exists—every room gets conditioned air, not just the ones with a wall unit. When you’re ready to compare specific models, our tested roundup of the best ducted heat pump systems breaks down top performers by efficiency, noise, and price.

Ducted Heat Pump Costs and Savings

Installing a ducted heat pump typically runs between $8,000 and $15,000 depending on your home’s size and the system’s efficiency rating. Monthly savings depend on what you’re replacing—homes switching from electric resistance heating often see the biggest drop, while those leaving natural gas see smaller gains.

The most common mistake homeowners make is skipping the heat load calculation. A system that’s too big short-cycles, struggles to dehumidify, and wears out faster. Portland’s checklist makes this non-negotiable in its program, and it should be in yours too.

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