Ceiling Cassette CONFORTO MHCAS | 24,000 BTU - R410A
SEER2 (Seasonal Energy Efficiency Ratio)
HSPF2 (Seasonal Heating Efficiency)
EER2 (Instantaneous cooling efficiency)
COP at -8 °C (Heating energy efficiency)
COP at -15 °C (Heating energy efficiency)
COP at -30 °C (MAX)
CFM (Airflow)
A large size that keeps its capacity when the cold sets in
To heat a large space through a Quebec winter, a unit's nominal size is not enough: what counts is the heat it still delivers when the thermometer plunges. The Ceiling Cassette CONFORTO MHCAS | 24,000 BTU - R410A stands out precisely on this point. The MHCAS24DACFC cassette is recessed into the ceiling and works with the MHSZ124DACFC outdoor unit, whose variable-speed compressor modulates its speed according to demand.
Its certified ratings are 20.5 SEER2, 11.0 EER2 and 11.5 HSPF2. The system is ENERGY STAR certified with the cold-climate designation under ENERGY STAR ID 4480246, its certificate still lists heating capacity at -30 °C, and it qualifies for a $2,520 LogisVert grant.
What the certificate shows in extreme cold
The certificate publishes three heating points, measured separately; we report each one as published.
- 21,000 BTU/h at -8 °C (17 °F), with a COP of 2.64.
- 25,800 BTU/h at -15 °C (5 °F), with a COP of 2.00, or 108 % of the nominal capacity.
- 20,000 BTU/h at -30 °C (-22 °F), with a COP of 1.50, or 83 % of the nominal capacity.
The last point is the most telling. Many heat pumps lose half their capacity, or more, at -30 °C. This one keeps more than four-fifths of it according to its certificate, and it still produces one and a half times as much heat as it uses in electricity. The -15 °C point, higher than the -8 °C one, comes from a separate test: we do not join the two into a curve.
This does not remove the need for backup heating: in a large space, we always recommend keeping the baseboards or the existing system for extreme nights and maintenance periods. But the backup will be used less often.
The spaces this size is meant for
The 24,000 BTU size targets large, single open volumes: the open main floor of a recent house, a large finished basement with an exercise room, a loft or a workshop, and many commercial spaces, a shop, a yoga or dance studio, a meeting room, a clinic waiting room. In a well-insulated building, it can heat and cool most of an open floor; in an older, heavily glazed building, it covers a smaller area.
One large unit or two smaller ones
A cassette heats and cools the space it is in. If the area to cover is divided into several closed rooms, two smaller units often give a better result than one large cassette. Conversely, in a truly open space, a single well-placed unit is simpler: one outdoor unit, one wall opening, one maintenance visit.
The choice is made with the load calculation. A unit too large for the room would idle most of the year and short-cycle in spring and fall; a unit too small would strain in January. We set out the reasoning in the quote, backed by the certificate's figures.
The electrical panel and the dedicated circuit
A unit of this size needs a dedicated circuit of appropriate capacity. In a house or a commercial space whose panel is already heavily used, we check during the visit that the necessary room remains. If a panel adjustment is required, it appears clearly in the written quote. In a commercial space, we also coordinate the connection location with the building manager when needed.
Distributing air in a large volume
The cassette spreads the air in four directions through the louvres around its grille. In a large space, this distribution reduces the temperature differences between the centre and the walls, where a wall-mounted heat pump would leave the opposite end under-heated. We place it between the areas of use, away from fixed workstations, and clear of a range or a hood.
In heating, warm air tends to collect under the ceiling, especially in a tall volume. The cassette's central position and the louvre setting help bring that air back toward the floor; in a loft, a ceiling fan set to low speed usefully completes the mixing.
Cooling an occupied space
A commercial space or a large reception room often hosts several people at once, and each one adds heat and moisture. In cooling, the cassette removes both: the moisture condenses on the coil and flows out through the drain. The variable-speed compressor follows the changes in occupancy rather than starting and stopping constantly.
The EER2 of 11.0 measures full-load efficiency during the hottest hours; the SEER2 of 20.5 measures efficiency over the whole season, when the unit spends most of its time at partial load. It is this second rating that best reflects the real use of a variable-speed unit.
The ratings, made clear
- SEER2 of 20.5: seasonal cooling efficiency; the higher it is, the less the unit uses for the same cooling over the summer.
- EER2 of 11.0: cooling efficiency at full load, in hot weather.
- HSPF2 of 11.5: seasonal heating efficiency, calculated for a reference climate milder than ours; useful for comparing models.
- COP: heat delivered per unit of electricity. An electric baseboard is at 1; this cassette is at 2.64 at -8 °C and still at 1.50 at -30 °C.
These ratings compare units; the actual bill depends on insulation, settings and the winter.
The technology: variable speed and R-410A
A heat pump moves heat instead of producing it with a resistance element. In winter, the refrigerant captures heat from the outdoor air, the compressor concentrates it and the cassette releases it; in summer, the cycle reverses. The system uses R-410A, a proven refrigerant found in a large share of the heat pumps installed in recent years and well known to technicians. A tight installation and a charge verified at commissioning are the basis of its reliability.
The $2,520 LogisVert grant
The system is listed in Hydro-Québec's LogisVert program, with $2,520 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, step by step
- Visit and load calculation. Survey of the space, insulation and glass areas, check of the electrical panel, choice of location.
- Ceiling mounting. The cassette is suspended from the structure, between the joists or above a suspended ceiling, level, with access to the filter and drain.
- Drain. Continuous drainage slope for condensate or, if the route requires it, a small pump.
- Outdoor unit. On a ground stand or a wall bracket suited to its size, above the snow line, clear of roof runoff and away from bedroom windows, including the neighbours'.
- Refrigerant lines. A single sealed opening and, outdoors, a line cover if needed.
- Electrical and commissioning. Connection of the dedicated circuit, leak test, evacuation, checks in heating and cooling, explanation of the settings.
Maintenance
Rinse the filter behind the grille every two weeks in season, more often in a busy commercial space. Keep the outdoor unit clear of snow and leaves: a unit of this size needs its full exchange surface during cold snaps. Plan annual HVAC maintenance of the coils, drain and electrical connections. In winter, white vapour during defrost and a short pause in heating are normal. 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 Ceiling Cassette CONFORTO MHCAS | 24,000 BTU - R410A. We measure the space, check the panel and compare one large unit with two smaller ones before signing.