3-Zone Heat Pump CONFORTO MHMZ | 27,000 BTU - R410A

The living room and two bedrooms on a single condenser: a whole small home in three zones

In a condo or a small house, three rooms account for most of daily life: the living room, the main bedroom and a second bedroom or an office. The 3-Zone Heat Pump CONFORTO MHMZ | 27,000 BTU - R410A equips each one with a wall head and connects them all to a single MHMZ327DACFC condenser. One unit outside, three set points inside.

The condenser serves 3 zones here, which is its maximum of 3. The wall heads intended for it are the MHWAL09DACFC and the MHWAL18DACFC. Its certified ratings are 23.0 SEER2, 12.5 EER2 and 10.6 HSPF2. The system is ENERGY STAR certified with the cold-climate designation under ENERGY STAR ID 2495138, and it qualifies for a $3,192 LogisVert grant.

A complete home, three zones

This size targets homes where three rooms carry all the comfort: a condo 5 ½, the ground floor of a bungalow with a living room and two bedrooms, or a small house whose kitchen is open to the living room. Each closed room gets its own head, and the kitchen benefits from the living-room head.

The result depends on the insulation. In a recent or renovated home, the three heads can become the main heat source. In an older house, we calculate the share the heat pump can take on in each room and the share left to the electric baseboards, then present it to you before signing.

The three heads and where they go

The MHWAL18DACFC, the larger of the two intended heads, goes in the living room: it is the largest and most glazed room. The bedrooms get the MHWAL09DACFC, smaller and well suited to a closed room used mostly at night. The exact combination is confirmed after the load calculation.

In a small home, the location of each head is decided carefully. In the living room, we place it so it blows toward the open kitchen without aiming straight at the sofa, and away from the stove, whose heat would skew the temperature reading. In a bedroom, the head goes high on the wall, preferably on an exterior wall to shorten the lines, with airflow that sweeps the room without falling on the bed. We show you each location before drilling.

The three heads share the condenser's capacity. With 3 zones out of a maximum of 3, every connection is used: the system covers the home as it is, with no room for a fourth space. If a basement is to be finished later, we point it out during the visit so the size is chosen with full knowledge.

A typical day, zone by zone

In the morning, the bedrooms ask for a little heat on waking while the living room stays at its daytime set point. During the day, the bedrooms are empty: their set point can stay a little lower, and the condenser concentrates its capacity on the living room. In the evening, demand moves back to the bedrooms. The inverter compressor follows this movement without abrupt starts, metering the R-410A refrigerant sent to each head according to its demand.

A single rule frames this operation: the three heads work in the same mode, heating or cooling, as on any multi-zone system of this type. In a home that lives through the same season from one room to the next, it goes unnoticed.

What the certificate shows for winter

The certificate lists 26,600 BTU/h at -8 °C (17 °F), with a COP of 2.30, and 25,000 BTU/h at -15 °C (5 °F), with a COP of 1.80. The maximum published capacity is 25,000 BTU/h at -15 °C. The two points are measured separately; we report each one as published.

At -15 °C, the three heads therefore share 93% of the 27,000 BTU nominal size. A COP of 1.80 means that at that temperature, each kilowatt-hour consumed returns 1.80 kilowatt-hours of heat, where a 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 210605813, published by NEEP.

The baseboards, kept in reserve

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 and take over during extreme cold. In cold, humid weather, the condenser also runs defrost cycles of a few minutes. The heads then stop blowing warm air and a cloud of vapour rises from the outdoor unit; this is normal.

This system's seasonal ratings

• 10.6 HSPF2: heating efficiency over the whole cold season. In Quebec, it is the rating that weighs most on the bill.
• 23.0 SEER2: cooling efficiency over a whole summer.
• 12.5 EER2: cooling at full load, during a heat wave.
• COP: the ratio between heat delivered and electricity consumed at a specific temperature, here 2.30 at -8 °C and 1.80 at -15 °C.

Cooling and humidity

In cooling, the system is built around a nominal size of 27,000 BTU/h, shared among the three rooms. The bedrooms are set for the night, the living room for the day, and an empty room can be shut off. The compressor runs for long periods at low speed, which removes moisture from the air and keeps the home comfortable without an overly low set point. Each head also offers a dehumidification mode for muggy days.

The $3,192 LogisVert grant

The system is listed in Hydro-Québec's LogisVert program, with $3,192 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.

Installing three heads in a small home

In a condo: approval first

In a condominium building, the condenser's location and drilling through exterior walls often fall under the syndicate's authority. Check the declaration of co-ownership and obtain the required approval before planning the work. We can provide the model numbers and the planned location to support the request.

Our installation

After the visit and the load calculation, the condenser is installed above the snow line, on a balcony, a wall bracket or a stand, sheltered from snow sliding off the roof. Each head gets its own refrigerant line set back to the condenser; the three are grouped in a line cover for a clean run along the wall. 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; they come out by hand. 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 3-Zone Heat Pump CONFORTO MHMZ | 27,000 BTU - R410A. We assess your three rooms and confirm the right size and your grant eligibility before signing.