One or two days
Most heat pump replacements in Memphis take one day for an outdoor unit only and one or two for a whole system. Duct work, a new circuit or a move of the outdoor unit can add time.
Bluffline Memphis Heat Pumps schedules install day after the permit is issued.
A typical day
Here is how a typical day runs, using a whole-system replacement in a Memphis ranch as the example.
Morning: out with the old
Protect the house
Drop cloths go down along the path to the air handler, and the work area gets cleared.
Recover the refrigerant
The old refrigerant is recovered into a tank with a recovery machine, not vented. That is required by law and it is the first job.
Remove the old equipment
The old outdoor unit comes off its pad, and the air handler or coil comes out of the closet, attic or crawlspace. Attic units often come out in sections through the hatch.
Midday: in with the new
The outdoor unit
The new heat pump goes on a level, raised pad with the maker’s clearances. A raised pad lets defrost meltwater drain away in winter.
The indoor half
The matched air handler, or a coil on your furnace for dual fuel, goes in where the old one stood. Attic units get a secondary pan and a float switch.
The line set
The two copper lines are brazed to both halves with dry nitrogen flowing through them, so no oxide forms inside.
Afternoon: prove it
Pressure test
The system is pressurized with nitrogen and watched for any drop. A drop means a leak, found and fixed.
Vacuum
A vacuum pump pulls the lines down below 500 microns and the reading is watched to confirm it holds. That removes air and moisture.
Charge
The system is charged by weight, with extra refrigerant for longer line sets, then checked against the maker’s targets.
Start and test
Cooling, heating, a forced defrost, the backup heat and the thermostat are each tested. Airflow and static pressure are measured. The commissioning checklist lists every reading.
End of day: the handover
Before we leave, we go through:
- The thermostat: what it shows, the strip lockout or dual fuel switchover, and the fan setting.
- The readings, written down.
- The filter size and where it goes.
- The outdoor unit: what defrost looks and sounds like in winter.
- The inspection, and when it is scheduled.
The old equipment leaves with us.
Permits and inspection
The mechanical permit is pulled before install day, from the office your town uses. Memphis, Germantown and unincorporated Shelby County use the joint Office of Construction Code Enforcement; Bartlett, Collierville and the Mississippi and Arkansas towns have their own offices. The inspection is scheduled after the system is running, and the service areas page names the office for each town.
What you’ll notice
A few things are new with a heat pump and worth knowing:
| Moment | What it means |
|---|---|
| A loud whoosh from outside in winter | The reversing valve shifting for defrost; normal |
| Steam from the outdoor unit | Frost melting during defrost; normal |
| Longer, quieter cycles | Correct sizing at work |
| Supply air in the 90s in winter | Normal for a heat pump |
The defrost guide explains winter behavior, and your first summer with a heat pump covers the warm season.
When it takes two days
A second day is common when the job includes more than the swap:
- Duct work, such as a new return, sealing a crawlspace trunk or new attic runs.
- A new circuit for strip heat on a gas-to-electric conversion.
- Moving the outdoor unit, with a longer line set and a moved disconnect.
- A difficult attic or crawlspace, where every piece moves slowly.
On those jobs the duct or electrical work often happens on day one and the equipment on day two, so the system is never left half-installed overnight in extreme weather.
Getting ready
A few things make the day go smoothly:
- Clear a path to the indoor equipment, the attic hatch or crawlspace door, and the panel.
- Move cars so the driveway is free for equipment.
- Keep pets in a closed room.
- Plan for a few hours without heating or cooling.
After install day
The inspection follows. Keep the start-up readings and model numbers with the warranty registration. The Memphis buying guide covers the whole decision for anyone still deciding.