Mitsubishi Floor-Mounted Indoor Units for Sunrooms, Lofts & Old Houses
A floor-mounted unit sits low on the wall like a radiator and warms a room from the floor up. The Mitsubishi MFZ-KJ is the answer for rooms with no usable wall height — sunrooms over the lake, knee-wall bedrooms under the roof, cathedral-ceiling great rooms in Adirondack camps — and for the spot under the front window where a cast-iron radiator or baseboard used to be. It's Hyper-Heat rated, mounts fully or partially recessed, and like every Mitsubishi indoor unit it also cools.
- Mitsubishi Diamond Contractor ELITE
- 12-year parts & labor warranty
- 180-Day Comfort Guarantee
- Veteran-owned · Ticonderoga, NY
Heat where you feel it first
Warm air rises. A wall unit mounted near the ceiling has to push heat down against that, which works fine in a standard eight-foot room and poorly in a room with a 16-foot peak. A floor-mounted unit releases warm air at ankle height from two outlets — one top, one bottom — and lets physics do the rest, so the floor is warm, the seating area is warm, and the heat distributes evenly before it reaches the rafters. In summer the same unit cools from the bottom with a multi-flow vane that sweeps air out into the room. The MFZ-KJ's rapid heating mode brings a cold sunroom up fast on a January morning.
- Hyper-Heat rated — 100% capacity at 5°F, operation to -13°F with an H2i outdoor unit
- Multi-flow vane controls airflow direction across the space
- Fully or partially recessed into the wall between studs for a slimmer profile
- Single-zone or multi-zone — pairs with SUZ or MXZ Smart Multi outdoor units
- Washable filters, handheld remote standard, MHK2 and app control optional
Specifications that matter
| Series | MFZ-KJ |
|---|---|
| Capacities | 9,000, 12,000, 15,000 and 18,000 BTU/h |
| Mounting | Surface, partially recessed or fully recessed; low on the wall |
| Heating | 100% capacity at 5°F, operates to -13°F with H2i outdoor unit |
| Airflow | Dual outlets (top and bottom), multi-flow vane, rapid heating mode |
| Sound (indoor, low) | About 22 dB and up |
| Filtration | Washable; optional deodorizing filter |
| Controls | Wireless remote standard; MHK2 thermostat, Comfort / kumo cloud app optional |
| Warranty | 12-year parts registered at commissioning; 12-year labor with Elite Care Plan |
Exact model and ratings are selected per zone at your free estimate; figures are typical for the current MFZ-KJ line.
Best for
- Sunrooms and three-season rooms with glass walls
- Bedrooms under the roof with knee walls
- Cathedral-ceiling great rooms in camps and lodges
- Replacing a cast-iron radiator or baseboard under a window
- Finished basements with low ceilings
- Rooms where a wall unit would sit over a bed or seating
Where the floor-mounted unit earns its keep
- The sunroom over the lake. Glass on three sides, no wall to hang anything on, cold in February and hot in July. A 12,000 BTU MFZ-KJ on the one solid wall solves both seasons. This is the single most common floor-unit job we do in Ticonderoga and Bolton Landing.
- Converted attics and half-story bedrooms. Knee walls are four feet tall. A floor unit fits; a wall unit doesn't.
- The 1880s parlor. The radiator under the front window is coming out with the boiler. The floor unit takes its place, matches the room's proportions, and gives the parlor cooling it never had.
- Camps with cathedral ceilings. Floor unit on the main level, small wall unit in the loft, both on one Smart Multi outdoor unit.
- Finished basements. Low ceilings and summer humidity; the floor unit's dry mode handles the damp.
Keep a clear path in front of the unit — not behind a couch — and we'll set it where the line set can reach the outdoor unit cleanly. Decided at the free estimate.
Floor-mounted vs. wall-mounted vs. baseboard
| MFZ-KJ floor-mounted | MSZ wall-mounted | Electric baseboard | |
|---|---|---|---|
| Needs wall height | No | Yes, ~7 ft+ | No |
| Heats from | Floor level | Ceiling level | Floor level |
| Cools | Yes | Yes | No |
| Heat per unit of electricity | About 3:1 | About 3:1 | 1:1 |
| Cold rating | H2i to -13°F | H2i to -13°F / -22°F (FS) | — |
| Efficiency | High | Highest | Lowest |
| Best in | Sunrooms, lofts, knee walls, radiator spots | Standard rooms | Nowhere, if you can help it |
Questions about floor-mounted units
Is a floor-mounted unit as efficient as a wall unit?
Nearly. Wall units carry the very highest ratings, but the MFZ-KJ is still a high-efficiency inverter unit with roughly three units of heat per unit of electricity, and in a room where a wall unit would heat the rafters first, the floor unit delivers more usable comfort per dollar.
Does it work with Hyper-Heat?
Yes. The MFZ-KJ is Hyper-Heat rated with H2i outdoor units: 100% of rated capacity at 5°F and operation to -13°F. We specify it for sunrooms and lofts in Lake Placid as well as Ticonderoga.
Can it be recessed into the wall?
Yes. The MFZ-KJ can be surface mounted, partially recessed or fully recessed between studs, which brings the profile close to a radiator cover.
Can it replace my radiator or baseboard?
That's one of its main jobs. It goes in the same spot under the window, heats the same way from floor level, and adds cooling. In a whole-home conversion off a boiler, floor units typically go where the largest radiators were.
What sizes does it come in?
9,000, 12,000, 15,000 and 18,000 BTU/h. The load calculation at the estimate picks the size for the room.
Does it cool a sunroom in summer?
Yes. The lower outlet and multi-flow vane sweep cool air across the floor, and dry mode pulls humidity on sticky lake days. Glass rooms have big cooling loads, which is why we size them carefully.
Rebates Available
North Country homeowners switching from oil, propane, wood or electric baseboard to a Mitsubishi cold-climate heat pump qualify for NYSEG or National Grid rebates through NYS Clean Heat, and Addison County, Vermont homes qualify through Efficiency Vermont plus utility bonuses. Rebate amounts change by program and tier — we tell you exactly what your home qualifies for at the free in-home estimate and handle the entire application for you.
What is your oil, propane or electric heat really costing you?
Enter your ZIP, home size and current fuel. See your real annual cost, what a Mitsubishi Hyper-Heat system would cost to run in North Country weather, and your 5-year cost of doing nothing.
Not sure how it would look? Snap a photo and see a Mitsubishi unit on your wall — free, 60 seconds.
- Your number, not an average. Modeled on your ZIP's heating degree days, your fuel price and your system's age.
- Three paths compared. Single-zone, hybrid with your existing furnace or boiler, or whole-home Hyper-Heat.
- Rebates confirmed for you. We tell you exactly what NYS Clean Heat or Efficiency Vermont will pay at the free estimate and handle the application.
- Emailed to you with a $250 code. Keep the report. Nobody calls unless you ask us to.