Roomwise DC Mini Splits replaces PTACs and through-wall air conditioners with mini splits in DC apartments and condos. The box under the window that rattles all night, the heat strip that runs up the winter bill, and the drafty opening around it all go.
Electricity heats nearly half of occupied DC homes, and in a PTAC that heat comes from a resistance strip. A mini split heats the same room with a heat pump and moves the noisy compressor outdoors.
Why people replace a PTAC
A PTAC packs heating and cooling into one box that sits in the wall. That’s convenient to install once, and it’s also why the unit is loud, leaky and costly to heat with.
- Noise. The compressor runs a foot from your couch or your bed. A mini split puts it outside, and the head inside runs only a fan.
- Heat strip costs. Most PTACs heat with an electric resistance element; some are heat pumps that fall back on a strip. Resistance heat turns each kilowatt-hour into one kilowatt-hour of heat, no more.
- Drafts. The sleeve is a large hole through the outside wall, sealed only by the chassis gasket and whatever foam someone added.
- Sticky summers. A loud on-off cycle cools the air without pulling much water out of it. Reagan National’s July dew point averages 66.4°F, so moisture matters as much as temperature.
A mini split’s inverter compressor runs long and slow instead, which dries the air as it cools; the dehumidification guide explains why. The window AC comparison covers the same trade-off for window units.
A new through-wall unit or a mini split?
If the building won’t allow an outdoor unit, a newer through-wall heat pump in the same sleeve is the simpler swap. If it will, a mini split is quieter, closes the opening and heats more efficiently.
When another through-wall unit makes sense
- Your board or building owner won’t approve any outdoor equipment or new exterior lines
- The sleeve is sound and the louver is part of a uniform facade the building wants unchanged
- You plan to move soon and want the least disruption
When a mini split is worth the extra work
- Noise in a bedroom or living room is the main complaint
- You heat with the PTAC’s strip for most of the winter
- The opening leaks air or water, and you want it closed properly
- A balcony, a rear wall or the roof can take an outdoor unit within the manufacturer’s line length
What happens to the old sleeve
The sleeve stays in the wall; pulling it out means rebuilding brick and the facade around it. What changes is how it’s closed, and whether it becomes the path for the new lines.
Closing it
An insulated panel fills the opening from inside, sealed at every edge against air and water. Outside, the louver stays in place or a matching blank replaces it. Keeping the louver means the facade looks the same, which helps when a board or a historic review is involved.
Using it as the line route
The line set, drain and control cable pass through a panel fitted in the sleeve and on to a bracket or balcony unit outside. No new hole goes through the brick, and the visible change on the facade is a small line-hide cover leaving the louver.
Wiring, heat and the drain
A PTAC plugs into its own receptacle, usually on a 208/230-volt circuit. A mini split’s outdoor unit is hard-wired through a disconnect, so the circuit gets checked against the new unit’s nameplate, not assumed.
- The circuit. If the existing wire and breaker match the outdoor unit’s requirements under NEC Article 440, the circuit can feed the new system. If the panel is full or the circuit is wrong, the plan says so. The electrical guide explains the options.
- Heat on the coldest nights. Washington averages about 10 nights a year below 20°F. For a room the PTAC heats alone, the plan says whether a mini split carries it through those nights or a backup is worth keeping; see winter performance.
- The drain. A PTAC drains through its sleeve or throws water onto its own coil. A mini split head needs its own drain path: through the wall to the outside, into a building drain where the building allows, or to a condensate pump.
What a PTAC replacement costs
A PTAC swap is a single-zone install with extra work at the wall. Price follows our install ranges, moved by what happens to the sleeve and where the outdoor unit can go.
- Roomwise’s typical range for a standard single-zone install is $3,000 to $6,000, for one room with a short run to a balcony or bracket and a usable circuit.
- Roomwise’s typical range for a standard multi-zone install is $5,000 to $14,000, for replacing two to four through-wall units on one outdoor unit.
- Roomwise’s typical range for a complex single-zone job is $11,000 to $28,500, where the unit goes on the roof, the run crosses several floors, or building or historic review adds steps.
What moves the price
- Closing the sleeve versus routing the lines through it
- A new louver or blank to match the facade
- Where the outdoor unit goes, and how it’s mounted
- Circuit work, or a panel with no room
- A condensate pump where the drain can’t fall outside
Your price comes from the site visit and arrives as a written estimate. The cost estimator gives a first number, and the operating cost guide shows what the switch from strip heat can mean on a Pepco bill.
Rebates for replacing a PTAC
Swapping a PTAC’s electric heat for a qualifying ductless heat pump falls under DCSEU’s electric-to-electric amount. The rebate needs the DOB permit we pull on every install, plus the equipment paperwork.
The current form pays $1,000 for ENERGY STAR certified equipment and $1,500 for ENERGY STAR Most Efficient. Where the system qualifies, the rebate can come off our invoice as an instant discount. Amounts and rules change during the program year, so check the rebates guide first.
In a condo or co-op building
In Navy Yard and downtown, about nine in ten homes sit in buildings of 20 or more units, and about three-quarters heat with electricity. Swapping one for a mini split changes the exterior, so the board has to agree.
The condo installation page covers the board package, balcony and roof options, and older buildings without separate electric meters. If you have three or more wall units, a multi-zone system can replace them from one outdoor unit, which gives the board one outdoor unit to review instead of three.