Ductless Double Zone Heat Pump Gree Multi+ Ultra Compressor 18 000 BTU Montreal
The Gree Multi Ultra 18 000 multi-zone heat pump heats and cools 2 rooms with a single outdoor unit. it delivers 17,000 BTU/h at −8 °C, heats down to −35 °C and qualifies for a $2,040 LogisVert grant. Installed by AirGreen in Montréal, Laval, Longueuil, the North Shore and the South Shore.
2 rooms, one outdoor unit.
Compared with the 48 multi-zone systems of 18,000 BTU we sell. Every number on this page carries its source.
The parts that make a multi-zone system.
Tap a part to learn more.
Outdoor unit
One compressor for the whole house. It supplies up to 2 heads and modulates from 7,000 to 21,000 BTU/h depending on what the rooms call for (NEEP).
Base pan heater
A heater keeps the outdoor unit’s base pan free of ice below 1 °C and during defrost (NEEP).
Refrigerant lines
One pair of lines per head.
Indoor heads
One head per room, each with its own remote and temperature. The combination is chosen in the “Zones” menu.
Control
Each zone is set separately, also from your phone.
Turn rooms on and off. Watch the power being shared.
One outdoor unit supplies every head: when several rooms call at once, they share its capacity. Pick an outdoor temperature.
Tell us your rooms. We tell you if this size is enough.
Pick the number of rooms and their size. The estimate targets a −15 °C day; it is a guide, the real calculation is done room by room at your home.
The whole series at a glance: find the box that fits you.
Each box is a product: the outdoor unit’s size, and the number of heads.
At −15 °C, it still delivers 121 % of its rated capacity.
Tap a temperature: certified capacity, efficiency and the cost of one hour of heating.
It slows down, it speeds up: the certified modulation range
Light bar: from minimum to maximum capacity. Dark mark: the rated value.
At every temperature, cheaper than baseboards.
Cost of one hour at full output, for the same heat delivered. Hydro-Québec Rate D, second tier: 11.142 ¢/kWh.
The official ratings, on the same scales as before.
SEER2, HSPF2 and EER2 come from the AHRI certification. The mark shows the median of the same-size multi-zone systems we sell.
A grant you can calculate, not guess.
The capacity at −8 °C comes from Hydro-Québec’s list of October 1, 2026. $120 per 1,000 BTU/h is the rate for ENERGY STAR cold-climate heat pumps (guide v1.10).
Where it ranks among same-size multi-zone systems.
Compared with the 48 multi-zone systems of 18,000 BTU we sell, using the LogisVert list figures. Weaknesses too, said plainly.
Against three other brands in its class.
Same rated size, other manufacturers. Pick the opponent.
One multi-zone or several wall units? Both sides, honestly.
We compare both options on your floor plan during the estimate.
What to know before installing a multi-zone system.
Dimensions, wiring and lines, drawn. Then our six steps.
The outdoor unit, dimensioned
One circuit for the whole house
Published sound levels, on one scale.
We use the outdoor figure to choose where the unit goes.
What is particular about this machine.
Only facts published by ENERGY STAR, NEEP or the manufacturer.
Every number, and where it comes from.
Each line carries its source; a line with no published value is not shown.
The manufacturer’s documentation, as PDF.
Everything we have written about this system.
Installation and distribution of a Multi Zone heat pump with two (2) zones. Gree Multi+ Ultra mini split with an 18 000 BTU compressor, in Greater Montreal.
OPTIMAL PERFORMANCE IN THE MOST DIFFICULT CLIMATES UP TO -35°C!
Multi+ ULTRA mini split units provide ULTRA heating and cooling powered by GREE's unique 2-stage/3-cylinder variable speed compressor.
This series is eligible for numerous provincial subsidies, such as “Efficient Heat Pumps”, “Chauffez Vert” or “RénoClimat”, and federal, such as “Greener Homes”, for up to 5000$.
Each outdoor coil has a corrosion-resistant acrylic resin coil coating to maintain energy efficiency in the harshest climates. This heat pump is made with the cold Canadian climate in mind.
Some Features:
- Sound levels up to 58 dB(A) on the outdoor unit (compressor).
- Up to 5 unique indoor units, allowing wide independent control flexibility.
- Energy Star
- 10 year warranty on parts and 10 years on the compressor directly from the manufacturer.
- 10 year labor warranty available!
- Heats even down to -35°C!
- WiFi
| Compressor Power |
Heads Power (Zones/Inside Units) |
| 18 000 BTU | 9 000 BTU + 9 000 BTU |
| 18 000 BTU | 9 000 BTU + 12 000 BTU |
What people ask us about multi-zone systems.
Can I heat one room and cool another at the same time?
No. On a multi-zone system like this one, every head works in the same mode, heating or cooling. Each room still keeps its own set temperature.
What happens when every room calls for heat?
They share the outdoor unit’s capacity: 17,000 BTU/h at −8 °C, 21,800 at −15 °C.
How many heads can I connect?
Up to 2 on this outdoor unit. This product is configured for 2 heads.
Can I mix head sizes?
Yes. The “Zones” menu offers 2 combinations, from 9 + 9 to 9 + 12 (in thousands of BTU). Each head is sized for its room.
How much is the LogisVert grant?
$2,040 according to Hydro-Québec’s list of October 1, 2026. The grant never exceeds 100 % of the cost before taxes; apply within 9 months of installation.
Is it ENERGY STAR certified?
Yes, cold climate, ID 2409882. It also meets the ENERGY STAR Most Efficient criteria, according to the ENERGY STAR database.
Down to what temperature does it heat?
Down to −35 °C.
Is it noisy?
Indoors, the reference head goes down to 26 dB(A). Outdoors, 58 dB(A): we place the unit away from bedroom windows.
Why a multi-zone instead of several wall units?
One outdoor unit on the wall and one circuit. In return, the rooms share the capacity, and if the outdoor unit stops, every zone stops.
What does the warranty cover?
Our sheet lists 10 years on the compressor and 10 years on parts; labour is not included by the manufacturer. AirGreen extended warranty: available.
A multi-zone system is planned room by room. At your home.
We measure every room, draw the line route and choose the right head for each zone. The on-site estimate is free and the quote arrives within 24 h.