Outdoor unit
The central air condenser is replaced with a cold-climate heat pump, which cools in summer and heats in winter.
Ducted heat pumps, using the ductwork you already have.
If the house has ducts from a furnace or central air conditioning, a heat pump can often use them. Whether it should depends on the ducts themselves, which is why we measure them before we recommend anything.
When ducted makes sense
A ducted heat pump moves warm or cool air through supply and return ducts, the same way a furnace or central air system does. Only grilles show in the rooms, and one system can serve a whole floor or the whole house.
It is usually worth considering when the house already has forced-air ductwork in reasonable condition, when a central air conditioner or furnace is due for replacement anyway, or when an attic air handler already serves the second floor. It is rarely the right answer for a radiator house with no ducts, where adding ductwork means opening walls and ceilings; that is what ductless mini-splits are for.
What gets replaced, and what stays
Indoor equipment
Either a new heat pump air handler replaces the furnace, or a heat pump coil is added to an existing furnace that stays on as backup.
Ductwork
Stays where it is sound and properly sized. Where it is not, runs are sealed, insulated, resized or supplemented before the new equipment goes in.
Checking the ducts
A heat pump delivers air at a lower temperature than a furnace, typically around 90 to 110°F against a furnace’s 120 to 140°F, so it has to move more air to deliver the same heat. Ducts sized only for summer cooling, or leaking into an unheated attic, often cannot do that quietly.
- Static pressure
- We measure the resistance of the duct system with a manometer at the air handler. High readings mean noise, weak airflow at the far rooms and a shorter life for the blower motor.
- Duct sizing and layout
- Each room’s calculated load is compared with the air its supply duct can carry. Undersized runs are enlarged or rerouted; a room the ducts cannot serve well may get its own ductless unit.
- Leakage and insulation
- Joints are sealed with mastic and runs in unconditioned attics or crawlspaces are insulated, so the heat reaches the rooms instead of the attic.
- Returns
- A system needs enough return air to breathe. Houses with one small central return often need another before a heat pump will run quietly.
Ducted or ductless?
Many houses end up with both: a ducted system for the floor that already has ducts, and ductless units for the rooms it cannot reach.
| Ducted | Ductless | |
|---|---|---|
| What shows in the room | Only supply and return grilles. | An indoor unit on the wall, floor or ceiling, or grilles for concealed units. |
| Room-by-room control | One thermostat per system, unless the ducts are zoned. | Each indoor unit has its own controls. |
| Needs existing ducts | Yes, in good condition and properly sized. | No. |
| Installation disruption | Low where ducts are sound; more if they need rework. | One three-inch opening per indoor unit. |
| Best suited to | Houses with forced-air ducts, replacing central air or a furnace. | Radiator and baseboard houses, additions, problem rooms. |
Can my central air conditioner be replaced with a heat pump?
Usually, yes. A heat pump takes the place of the outdoor condenser and cools just as an air conditioner does, then heats in winter. Whether the existing ducts and indoor equipment can carry the heating load is what the assessment checks.
Will the air feel as warm as from a furnace?
The air at the grille is cooler than a furnace’s blast, and the system runs longer at a steadier pace. Rooms stay at an even temperature rather than warming quickly and cooling off between cycles.
Do I need new ductwork?
Often not all of it. Sealing, insulating and resizing a few runs is common; full replacement is only needed when the ducts are badly undersized or damaged. The quote says exactly which runs change.
Find out whether your ducts can do it
The assessment includes a static pressure test and a room-by-room load calculation, so the recommendation rests on measurements rather than guesses.