Understanding the ducted air-to-air heat pump and its uses for heating and cooling
How it works: outdoor unit, duct network and supply diffusers
A ducted air-to-air heat pump captures heat from outdoor air via an outdoor unit. It transfers it to an indoor air handler, often installed in the attic. An insulated duct network then distributes warm or cool air to supply diffusers. A return duct brings air back to the air handler, with filtration and control, and dampers can create zones.
Differences from an air-to-water heat pump and a classic split AC
Unlike an air-to-water heat pump, there's no water circuit, no radiators, no underfloor heating. Comfort comes from air distribution, for both heating and cooling. Compared with a wall-mounted split, a ducted system is more discreet and more even, but it requires space in a dropped ceiling and good flow-rate balancing.
When a ducted heat pump makes the most sense: renovation, attics, zones to serve
It makes sense in renovation when the attic is accessible, or when a dropped ceiling is planned. It works well if several rooms need to be served, with a day/night separation. It's also a good choice for improving summer comfort, while keeping a backup system if winters get very cold.
Sizing a ducted heat pump correctly to avoid overconsumption and discomfort
Assessing heating needs: volumes, insulation, orientation, room usage
The right starting point is a room-by-room heat-loss assessment. You start from the volumes to heat, the actual insulation (walls, roof, floor), orientation and glazing. Add usage patterns. A bedroom doesn't have the same hours or setpoint as a living room. An oversized heat pump will short-cycle, consume more and last less long.
Cooling sizing: solar gains, thermal mass, room by room
For cooling, you factor in solar gains, protections (shutters, brise-soleil), the building's thermal mass and internal gains. Aim for a room-by-room calculation to avoid an AC unit that blasts cold air then shuts off quickly. That's the typical scenario for discomfort and humidity issues.
Points of attention: power, airflow, sound levels, diffuser placement
Check the useful power under design conditions and the modulation capacity. On the duct side, airflow, pressure losses and balancing matter as much as the unit itself. Respect sound level limits, place diffusers to avoid drafts, and plan for a properly sized return air path.
Preparing the site: ducts, air distribution and integration into the existing structure
Designing the duct network: routing, diameters, balancing and pressure losses
Before installing a ducted heat pump, draw a simple layout that's as short as possible. Choose diameters consistent with room-by-room flow rates, to limit noise and pressure losses. Plan for accessible takeoffs, comparable lengths between branches, then final balancing at the diffusers with flow-rate measurement.
Integration in renovation: dropped ceilings, attics, technical runs and accessibility
In renovation, the duct network often runs through the attic or a dropped ceiling. Keep enough height for bends, insulate ducts in unheated zones to avoid condensation and losses, and reserve an access hatch for maintenance of the indoor unit, filters and connections.
Zoning and control: thermostat, zones, dampers, control system to optimize comfort
Comfort comes from proper zoning. A main thermostat, per-zone sensors and motorized dampers let you adjust flow rates by usage. Set realistic setpoints and time schedules. You gain stability without overconsuming: if needed, use a heating scheduler to fine-tune the schedules.
Successfully installing and commissioning a ducted air-to-air heat pump
Key steps: mounting, refrigerant lines, condensate drainage, sealing
A ducted heat pump comes down to precision work first. Rigid mounting, anti-vibration pads, maintenance access. Install the refrigerant lines with continuous insulation, clean bend radii, mechanical protection, then vacuum pull-down and a leak test before opening the valves. For condensate, plan for a slope, a trap and insulation of cold sections to avoid odors and condensation. On the duct side, take care of duct and plenum sealing, or air will escape into the attic instead of reaching the rooms.
Commissioning settings: flow rates, temperatures, heating and cooling tests
Set the flow rates room by room. Measure at the diffusers, adjust the dampers, then check noise. Calibrate the setpoint and the supply-air curve per the manufacturer's manual. Run tests in both heating and cooling mode, check the temperature delta at the diffuser, defrosting, and condensate drainage in cooling mode.
Checks to document: compliance, safety, maintenance and usage advice for the client
Write up a commissioning report. Log the electrical checks, the leak test, and the final settings. Remind the client about maintenance: filter cleaning, access to the diffusers, and periodic service visits if the refrigerant requires a regulatory check. Give simple advice: keep the returns clear, avoid extreme setpoints, and use the zones when they exist.
Costs, grants and sales arguments in 2026 for selling a ducted heat pump
Budget to plan for: equipment, duct network, labor and options (zoning, filtration)
For a ducted heat pump, the budget breaks down into 4 lines. A realistic installed price range, depending on floor area, attic access and number of rooms. The equipment (outdoor unit, ducted module, controls) is often the biggest line. The network (insulated ducts, plenums, diffusers) and the installation (penetrations, sealing, commissioning) can quickly add up. Zoning, upgraded filtration or design diffusers add extra cost.
Grants available in 2026: points to check depending on the home and type of work
On the grants side, check eligibility for the technology first. An air-to-air heat pump doesn't always fall into the same categories as air-to-water. To confirm case by case: the CEE premium, and sometimes support through a renovation pathway. On the VAT side, good news: starting September 1, 2026, 5.5% VAT also applies to air-to-air heat pumps compliant with the July 13, 2026 order (A++ class for mono-split, A+ for multi-split, F-Gas refrigerant, connected control), in homes completed more than two years ago. In all cases, RGE certification and a detailed invoice remain the basics.
Field arguments: summer/winter comfort, discretion, energy savings and maintenance
On site, sell the experience. Immediate comfort in winter and summer, even temperatures, and a clean look since only the grilles are visible. Savings mainly come from replacing electric convectors or an old system. On maintenance, emphasize accessible filters, regular checks, and cleaning the diffusers to keep the air healthy. To frame the obligations and best practices, refer to regular servicing and the points to document.
