4-Zone Heat Pump CONFORTO MHMZ | 36,000 BTU - R410A
The Conforto MHMZ 36 000 multi-zone heat pump heats and cools 4 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.
4 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.
Two offices, a living room and a bedroom: four zones for a home where people also work
Now that work often happens at home, rooms are no longer used the way they were. Two offices are full from nine to five, the living room fills up in the evening and the bedroom is only used at night. Heating the whole house to the same temperature all day no longer makes sense. The 4-Zone Heat Pump CONFORTO MHMZ | 36,000 BTU - R410A gives each of these four rooms its own wall head and set point, all connected to a single MHMZ436DACFC condenser.
This 3-ton condenser serves 4 zones here, which is its maximum of 4. 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.
Working from home changes how you heat
When two people work in two separate rooms, those two rooms are the ones that need to be comfortable during the day, not the bedroom or the living room. With one head per room, the offices keep their working set point while the rest of the house stays a little cooler. In the evening, demand shifts to the living room; at night, to the bedroom. Each zone only consumes when it is in use.
This size targets a complete mid-sized home: a two-storey whose upper floor has a bedroom and two small rooms converted into offices, a bungalow with a basement office, or a large condo. The result depends on the insulation; in an older house, the electric baseboards stay in place for deep cold.
Four heads, four uses
The MHWAL18DACFC, the largest of the three intended heads, goes in the living room. The MHWAL12DACFC suits the main bedroom, and the MHWAL09DACFC the offices, which are generally small rooms. The load calculation confirms each choice, taking into account each room's exposure and the heat given off by computers and screens.
The four heads share the condenser's capacity. During the day, the two offices take most of it; in the evening, the living room. With 4 zones out of a maximum of 4, every connection is used.
The sun-exposed office, a case to plan for
One rule applies to every multi-zone system of this type: the heads on the same condenser work in the same mode, all heating or all cooling. In most homes, this goes unnoticed. A south-facing office, with computer equipment on all day, can however get too warm on a sunny April afternoon while the rest of the house still asks for heat.
We take this into account from the visit onward: the choice and placement of the office head, blinds or curtains to cut direct sun, a lower set point for the office in heating mode. On these shoulder-season days, a slightly lower office set point almost always settles the matter. We prefer to explain it before the installation rather than let you find out in April.
Winter according to the certificate
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 -15 °C, the four heads therefore share 100% of the condenser's nominal size. A COP of 1.90 means that at that temperature, 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.
Backup heat and defrost
The certificate does not publish a point colder than -15 °C. We therefore recommend keeping the existing baseboards, set slightly below the heads' set point; they stay off for most of the winter. In cold, humid weather, the condenser also runs defrost cycles of a few minutes, during which the heads stop blowing warm air and a cloud of vapour rises from the outdoor unit. This is normal, and the baseboards fill in these short pauses.
The inverter compressor and small demands
A home where people work creates many small demands: a single office occupied on a Friday, a bedroom warming up before bedtime. The inverter compressor adapts by running slowly and metering just enough R-410A refrigerant for the head that is calling. It speeds up when several zones ask at once, without the repeated starts that would wear out the unit.
Summer: cool offices during working hours
In cooling, the system is built around a nominal size of 36,000 BTU/h for the four zones. The offices, warmed by the sun and the equipment, are cooled during the day, the bedroom only for the night. Extended low-speed operation removes moisture from the air, which makes a working day more comfortable without cold air blowing on the desk. Each head also offers a dehumidification mode.
The ratings, in plain terms
The HSPF2 of 10.3 measures heating efficiency over the whole cold season; in Quebec, it is the rating that weighs most on the bill. The SEER2 of 22.2 measures cooling efficiency over a whole summer, and the EER2 of 13.6 measures cooling at full load, during a heat wave. The COP expresses efficiency at a specific temperature: 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
- Visit and load calculation: each room is measured, and its exposure and use are noted.
- Head placement: in an office, the head blows across the room without aiming directly at the workstation.
- Condenser: above the snow line, on a wall bracket or a stand, sheltered from snow sliding off the roof.
- Refrigerant lines: one set per head, grouped in a line cover on the facade or run indoors when possible.
- Drains: one sloped condensate drain per head.
- Electrical: a dedicated circuit for the condenser, checked at the panel.
- Commissioning: vacuum, leak test, check of each zone and setup of the four remotes with you.
Maintenance
Rinse the filters of all four heads every two weeks in season, preferably on the same day. Keep the condenser clear of snow 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 4-Zone Heat Pump CONFORTO MHMZ | 36,000 BTU - R410A. We assess your four rooms and how they are used, 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 4 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.