Mitsubishi Hyper-Heat Outdoor Units
The cold-climate engine behind every system we install: full rated heating at 5°F, still running at -13°F, and one outdoor unit for up to eight rooms.
- Mitsubishi Diamond Contractor ELITE
- 12-year parts & labor warranty
- 180-Day Comfort Guarantee
- Veteran-owned since 2013
Why this outdoor unit and not a cheaper one
A conventional heat pump loses heating capacity as the outdoor air gets colder — by 20°F many are down to half, and by 5°F they're a very expensive fan. Mitsubishi's H2i® compressors use flash injection to keep pushing refrigerant at full pressure in low ambient temperatures, so the system delivers 100% of its rated heat at 5°F and keeps operating to -13°F. That is the line between a heat pump that can be your only heat in Cambridge or Ticonderoga and one that can't.
Single-zone MUZ-FS outdoor units run one indoor unit at the highest efficiency in the line. Multi-zone MXZ-SM units run two to eight indoor units of any style from one pad or wall bracket, with branch boxes for larger homes. All are inverter-driven, whisper-quiet, and sized by us from a load calculation, never a rule of thumb.

Specifications that matter
| Single-zone | MUZ-FS (H2i®): 6,000 – 18,000 BTU/h, up to 33.1 SEER2 |
|---|---|
| Multi-zone | MXZ-SM (H2i®): 20,000 – 48,000 BTU/h, 2–8 indoor units |
| Heating capacity | 100% at 5°F; continued operation to -13°F |
| Sound (outdoor) | approximately 49–58 dB — a normal conversation |
| Refrigerant | R-454B on current models (2025+); R-410A on prior generation |
| Mounting | Ground stand 12–18 in above grade, or wall bracket |
| Electrical | Dedicated circuit; 15–50A depending on capacity |
| Warranty | Mitsubishi extended warranty registered at commissioning; 12-yr parts & labor with Elite Care Plan |
Exact model, capacity and efficiency ratings are selected per zone at your free estimate. Figures shown are typical for current Mitsubishi Electric residential lines.
Best for
- Whole-home conversions from oil, propane or electric baseboard
- Any Upstate NY or Vermont home where the heat pump is the primary heat
- Multi-zone homes with mixed indoor unit styles
- Camps and cabins that need reliable heat when nobody is there
Questions about hyper-heat outdoor units units
What happens below -13°F?
The unit keeps running at reduced output rather than shutting off; the house coasts on its thermal mass. Cambridge sees a few nights a year below that. Tight homes barely notice; drafty ones may want a small backup. We'll tell you which you have.
Why does it steam and stop in winter?
That's a defrost cycle: the outdoor coil frosts in damp cold, and the unit reverses for a few minutes to melt it. Normal. Solid ice that never clears is a service call.
Where should the outdoor unit go?
On a stand or wall bracket above the snow line, out of the roof drip line, with clear airflow. North-facing is fine — H2i® doesn't need sun. Away from bedroom windows if you're sensitive to the fan.
How many indoor units can one outdoor unit run?
Up to eight on a large MXZ multi-zone with branch boxes. Most homes use two to five. Capacity is what matters, not the count — we size it so every zone can run at once on the coldest night.
What's the refrigerant change about?
New 2025+ models use R-454B, a lower-global-warming-potential refrigerant required by federal rule. Performance is the same; equipment cost rose slightly. Details in our refrigerant change guide.
Will it run during a power outage?
Not without power — but it draws little enough that a modest standby generator or battery runs it comfortably. See our generator pairing guide.
Rebates: $6,000–$10,000
New York homeowners switching from oil, propane or electric baseboard to a Mitsubishi cold-climate heat pump qualify for NYS Clean Heat utility rebates through National Grid or NYSEG — the highest tier goes to whole-home conversions. Vermont homes get a set per-unit amount through Efficiency Vermont plus utility bonuses. We confirm your exact number at the free estimate and submit every application for you.
Get an exact price for your home
Takes 30 seconds. We reach out within one business day, visit your home, size the system properly, and hand you a written price with every rebate already applied. No pressure, no obligation.
- $6,000–$10,000 in NY rebates — we file the paperwork
- 18 months, 0% interest financing available
- 12-year parts & labor warranty with our Elite Care Plan
- 180-Day Comfort Guarantee on qualifying installs
Prefer to talk? Call or text (518) 719-5614
Ready for one system that heats and cools — with no ductwork?
Free estimate, rebates filed for you, installed in days. Talk to a Mitsubishi Diamond Contractor ELITE.