Window units are loud, they only cool one room, and they leave the rest of the house uneven. For a family home with a nursery, a couple of bedrooms, and busy shared spaces, that setup stops working pretty quickly.
Jackie & Patrick M. in Lowell wanted real cooling in every room without the noise and the window boxes. We installed a 5-zone Mitsubishi ductless heat pump, with a single outdoor unit feeding five indoor heads, one for each of the spaces that mattered most: the babies’ room, the spare bedroom, the master, the kitchen, and the TV room.
The Challenge
Five rooms, no central air
The home didn’t have a good cooling option before this project:
- There was no central AC — the family relied on window units to get through the summer.
- Window units are noisy and uneven, cooling one spot while other rooms stay warm.
- A babies’ room needs steady, quiet, controllable temperature, which a window box doesn’t do well.
They wanted every room comfortable and quiet, with the ability to set each space to its own temperature.
Our Solution
A 5-zone Mitsubishi ductless system, one head per room
We installed a single-outdoor, five-indoor Mitsubishi system sized for cooling, with each head matched to the room it serves:
Outdoor unit:
- Mitsubishi MXZ-5D36NL multi-zone heat pump
- 36,000 BTU / 3 tons
- 5-zone, on a new base, pad, and stand
Five indoor heads (one per room):
- Two Mitsubishi MSZ-GX06NL (6,000 BTU)
- Two Mitsubishi MSZ-GX09NL (9,000 BTU)
- One Mitsubishi MSZ-GX12NL (12,000 BTU)
- Serving the babies’ room, spare bedroom, master, kitchen, and TV room
Installation details:
- Up to 25′ of line set, wiring, and covers to each head
- Mounting, wiring, charging, and condensate disposal for every zone, with penetrations sealed
- New 30-amp electrical circuit run from the panel to the outdoor unit
- Pressure test, evacuation, and refrigerant charged to the calculated line-set weight (R454B), then full system test
Controls: Each indoor head runs independently, so every room can be set to its own temperature instead of fighting over one thermostat.
Why This Design Was the Right Fit
For a home with no ductwork and five different spaces to cool, a multi-zone ductless system made the most sense:
- Room-by-room control. Five separate heads mean the babies’ room, the bedrooms, and the living spaces each hold their own temperature.
- Quiet and out of the window. Wall-mounted heads are far quieter than window units and free up the windows.
- No ductwork needed. A ductless system cools the whole home without tearing into walls to run ducts.
- Right-sized for the home. A 36,000 BTU / 3-ton outdoor unit is matched to the five rooms it serves.
The Result
Jackie & Patrick went from window units to quiet, room-by-room cooling across the whole home:
Highlights:
- Five zones, five thermostats — independent comfort in every room
- Whole-home cooling where there was no central AC before
- Quiet wall-mounted heads in place of window units
- 36,000 BTU / 3-ton Mitsubishi system sized for the home
- Installed and tested, completed June 2026
Equipment Used
System | Mitsubishi multi-zone (5-zone) ductless heat pump |
Outdoor unit | Mitsubishi MXZ-5D36NL, 36,000 BTU / 3 tons |
Indoor heads | 2x MSZ-GX06NL, 2x MSZ-GX09NL, 1x MSZ-GX12NL (5 total) |
Rooms served | Babies’ room, spare bedroom, master, kitchen, TV room |
Design | Sized for cooling |
Refrigerant | R454B |
Electrical | New 30-amp circuit from panel to outdoor unit |
Location | Lowell, MA |
Completed | June 2026 |
Project Snapshot
Want cooling in every room without window units?
If your home has no central air and you’re tired of hauling window units in and out, a Mitsubishi ductless system can cool every room quietly, with independent control in each space. Pespisa designs and installs multi-zone systems sized for your home.