3-Zone Heat Pump CONFORTO MHMZ | 36,000 BTU - R410A
The Conforto MHMZ 36 000 multi-zone heat pump heats and cools 3 rooms with a single outdoor unit. ENERGY STAR cold-climate certified, it delivers 33,000 BTU/h at −8 °C, heats down to −30 °C and qualifies for a $3,960 LogisVert grant. Installed by AirGreen in Montréal, Laval, Longueuil, the North Shore and the South Shore.
3 rooms, one outdoor unit.
Figures come from the manufacturer’s data and the AHRI certification.
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 4 heads.
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.
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 100 % of its rated capacity.
Tap a temperature: capacity, efficiency and the cost of one hour of heating.
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.
A grant you can calculate, not guess.
The capacity at −8 °C. $120 per 1,000 BTU/h is the rate for ENERGY STAR cold-climate heat pumps (guide v1.10).
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.
A railroad-style plex unit, heated and cooled from front to back in three zones
Montreal plex units often share the same layout: a double living room at the front, bedrooms in the middle, the kitchen and dining room at the back, all linked by a long hallway. A single wall-mounted heat pump cannot serve such a stretched-out home. The 3-Zone Heat Pump CONFORTO MHMZ | 36,000 BTU - R410A places one head at the front, one in the middle and one at the back, all connected to a single MHMZ436DACFC condenser.
This 3-ton condenser serves 3 zones here and accepts up to 4 at most. The wall heads intended for it are the MHWAL09DACFC, the MHWAL12DACFC and the MHWAL18DACFC. Its certified ratings are 22.2 SEER2, 13.6 EER2 and 10.3 HSPF2. The system is ENERGY STAR certified with the cold-climate designation under ENERGY STAR ID 2495072, and it qualifies for a $3,960 LogisVert grant.
The railroad layout, a challenge for a single head
In a railroad-style unit, air does not travel from one end to the other. A head installed in the living room keeps the front comfortable, but the kitchen, at the end of the hallway, stays cold in winter and hot in summer. The middle bedrooms, often without a street-facing window, have different needs again. Three zones match this natural division: the front, the middle and the back, each with its own set point.
This size also suits a semi-detached or a row house whose layout stretches back in depth. In every case, the insulation of the exterior walls and the quality of the windows matter as much as the floor area; an old plex does not have the same envelope as a renovated unit, and the load calculation takes that into account.
Three heads, from front to back
The MHWAL18DACFC, the largest of the three intended heads, usually goes in the double living room, the largest and most glazed room. The MHWAL12DACFC suits the kitchen and dining room at the back, and the MHWAL09DACFC the middle bedroom. The load calculation confirms each choice.
The three heads share the condenser's capacity. In the evening, the living room and kitchen take the largest share; at night, the bedroom does. With 3 zones out of a maximum of 4, one connection remains free for a second bedroom later, after checking the remaining capacity.
Where the condenser goes in a plex
In a plex, the condenser is most often installed at the back: on a bracket fixed to the rear facade, on the balcony or on the roof of a shed, always above the snow line. We take into account the snow and ice falling from upper balconies, access for maintenance and the neighbours' windows. In a divided co-ownership, the location and drilling through exterior walls often fall under the syndicate's authority: check the declaration of co-ownership and obtain approval before the work.
Main heating, even at -15 °C
The certificate lists 33,000 BTU/h at -8 °C (17 °F), with a COP of 2.40, and 36,000 BTU/h at -15 °C (5 °F), with a COP of 1.90. The maximum published capacity is 36,000 BTU/h at -15 °C. The two points are measured separately; we report each one as published.
At -8 °C, the published point corresponds to 92% of the nominal size; at -15 °C, the condenser delivers all of it. For a plex unit heated with baseboards, this means the three heads can carry most of the heating through most winters. A COP of 1.90 means that at -15 °C, each kilowatt-hour consumed returns 1.90 kilowatt-hours of heat, where an electric baseboard returns one. ENERGY STAR's cold-climate designation confirms that the combination meets the low-temperature performance criteria.
These figures come from certificate AHRI 210605816, published by NEEP.
What is left to the baseboards
The certificate does not publish a point colder than -15 °C. The electric baseboards therefore stay in place, set slightly below the heads' set point: they are off most of the time and take over during extreme cold. They also serve during defrost cycles, those few minutes when, in cold, humid weather, the condenser melts the frost off its coil; the heads then stop blowing warm air and a cloud of vapour rises from the outdoor unit.
What happens in the condenser
The inverter compressor does not run on an on-off cycle. It speeds up when several heads call and slows down when the set points are reached, metering the R-410A refrigerant sent to each head according to its demand. Shutting off an unoccupied zone leaves the other two running. As on any multi-zone system of this type, the three heads work in the same mode, heating or cooling.
Summer in a railroad-style unit
In cooling, the system is built around a nominal size of 36,000 BTU/h for the three zones. The front gets the sun from the street, the back the heat from the kitchen, and the poorly ventilated middle bedroom holds on to warm air. With a head in each, the window air conditioners disappear and each room is set separately. Extended low-speed operation removes moisture from the air; each head also offers a dehumidification mode.
The 22.2 SEER2, 13.6 EER2 and 10.3 HSPF2 ratings
- SEER2: cooling efficiency over a whole summer.
- EER2: cooling at full load, during a heat wave; at 13.6, it is a strong point of this system.
- HSPF2: heating efficiency over the whole cold season, the rating that weighs most on the bill in Quebec.
- COP: the ratio between heat delivered and electricity consumed at a specific temperature, here 2.40 at -8 °C and 1.90 at -15 °C.
The $3,960 LogisVert grant
The system is listed in Hydro-Québec's LogisVert program, with $3,960 for the owner of an existing home, according to the list in effect on the installation date. We confirm eligibility before signing and prepare the detailed invoice, model numbers and proof of payment. Our page on the efficient heat pump grant summarizes the program's conditions.
Installation and maintenance
Our installation
In a railroad layout, the line routes need some thought. Each head gets its own refrigerant line set back to the condenser. The one for the back head is short; the one for the front head is the longest and runs, depending on the building, outside in a line cover, through a basement ceiling or through a closet. We show you each route before drilling. Each head also has its own sloped condensate drain.
The condenser is connected to a dedicated circuit, checked at the panel during the visit. Commissioning includes the vacuum, the leak test, a check of each zone and setup of the three remotes with you.
Maintenance
Rinse the filters of all three heads every two weeks in season; the kitchen one gets dirty faster. Keep the condenser clear of snow, ice falling from the balconies and leaves, without covering it in winter. One HVAC maintenance visit per year cleans the coils, fans and drains and checks the electrical connections. Our cleaning service takes over when you prefer to hand off the annual visit.
AirGreen, for the life of the installation
A family business active for more than fifteen years in Montreal, Laval, Longueuil, the North Shore and the South Shore, we hold RBQ licences for ventilation, refrigeration and electrical work and carry $5,000,000 in liability insurance. The in-home assessment is free, the quote is in writing, and our financing options let you choose the right unit rather than the cheapest one.
Request your free estimate for the 3-Zone Heat Pump CONFORTO MHMZ | 36,000 BTU - R410A. We assess your home from front to back and confirm the right size and your grant eligibility before signing.
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: 33,000 BTU/h at −8 °C, 36,000 at −15 °C.
How many heads can I connect?
Up to 4 on this outdoor unit. This product is configured for 3 heads.
How much is the LogisVert grant?
$3,960. 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 2495072.
Down to what temperature does it heat?
Down to −30 °C.
Is it noisy?
Outdoors, 62 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.
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.