Description
The Comfort-aire MBB120AKCN0E01S is a 10-ton, 13.7 EER water source heat pump package unit built for commercial and light-industrial buildings that already have a hydronic loop — the kind of installation where a conventional split system simply won't work. It runs on 230V three-phase power and handles both heating and cooling from a single horizontally-mounted cabinet with left-return, back-supply airflow. If you're replacing an aging water source unit in an office building, hotel corridor, or multi-tenant commercial space and need a proven 10-ton solution that fits the existing ductwork orientation, this is the unit to spec.
Key Features
- 10-Ton Capacity: Moves enough air and BTUs to condition large open commercial spaces or multiple zones from a single package unit.
- 13.7 EER Rating: Delivers strong energy efficiency for a water source system — important when this unit runs year-round in a building with continuous occupancy.
- Belt-Driven Blower: Belt-drive fan design lets you adjust airflow to match static pressure requirements of the duct system — useful in retrofit situations where duct sizing isn't ideal.
- Left Return / Back Supply Orientation: Matches the specific horizontal airflow configuration common in drop-ceiling commercial corridors and plenum-fed systems, reducing the need for costly duct transitions.
- Water Source Heat Pump: Pulls heating and cooling from a shared water loop rather than outdoor air, so performance stays consistent regardless of outside temperature extremes.
- 230V Three-Phase Power: Designed for commercial electrical infrastructure — runs efficiently on the three-phase service already present in most commercial buildings.
Is this the right unit for your project?
A 10-ton unit is sized for roughly 3,000–4,000 square feet of commercial space under typical load conditions — think a large open office floor, a hotel common area, or a multi-room suite. That's a rule of thumb; actual sizing requires a Manual J or equivalent commercial load calculation. Undersizing this unit in a high-occupancy or high-glass building leads to constant run time and premature wear. Oversizing causes short cycling, poor humidity control, and energy waste. This unit also requires a functioning closed-loop water system at the correct entering water temperature range — if the loop isn't properly sized and maintained, efficiency drops fast.
Water source heat pump vs. air-cooled package unit
An air-cooled package unit rejects heat to outdoor air, which means performance drops when it's very hot or very cold outside. A water source heat pump like the MBB120AKCN0E01S rejects heat to a shared water loop, which stays at a much more consistent temperature year-round. In a commercial building where dozens of units share one loop, the system can actually transfer heat from interior zones that are cooling to perimeter zones that need heat — no energy wasted. The trade-off: you need an existing hydronic loop, a cooling tower, and a boiler to maintain loop temperature. Water source makes sense in multi-tenant commercial buildings. Air-cooled makes more sense when there's no loop infrastructure and you're starting from scratch.
Where it fits best
- Multi-tenant office buildings with a shared water loop
- Hotel guestroom corridors and common areas
- Retail or commercial spaces in high-rise or mixed-use buildings
- School or university buildings with existing hydronic HVAC infrastructure
- Large-footprint commercial renovation where existing duct orientation is left-return / back-supply
Why water source efficiency holds up year-round
Air-to-air systems lose efficiency as outdoor temperatures swing to extremes — capacity drops in deep winter and EER falls in peak summer heat. Water source systems avoid that problem because the loop temperature is actively maintained, typically between 60°F and 90°F. The MBB120AKCN0E01S's 13.7 EER rating is achieved under those controlled loop conditions, which means it performs close to that rating consistently across seasons. For a 10-ton unit running in a continuously occupied commercial building, that consistency translates directly into predictable energy costs and fewer demand spikes on the utility bill.
Installation & what else you’ll need
The MBB120AKCN0E01S requires 230V three-phase power — confirm the electrical service matches before ordering. A licensed electrician needs to run the disconnect and whip to the unit's electrical knockouts. On the mechanical side, you'll connect supply and return water lines to the unit's water coil; loop flow rate and entering water temperature must fall within Comfort-aire's specified range for this model. The horizontal cabinet mounts in a drop-ceiling or utility plenum space — verify structural support can handle the unit's operating weight. Left-return and back-supply duct connections need to be sealed and matched to the existing duct system. A compatible commercial thermostat or building automation system controller is required but not included. This is not a DIY installation — a licensed HVAC contractor with water source heat pump experience should handle commissioning, including loop pressure checks and refrigerant circuit verification.
Frequently Asked Questions
What is the cooling capacity of the Comfort-aire MBB120AKCN0E01S?
The MBB120AKCN0E01S is a 10-ton water source heat pump package unit. Ten tons equals 120,000 BTU/h of nominal cooling capacity. Actual delivered capacity depends on entering water temperature and airflow, so always verify with the manufacturer's performance data for your specific loop conditions.
What voltage does the Comfort-aire MBB120AKCN0E01S require?
The MBB120AKCN0E01S runs on 230V, three-phase power. It is not compatible with single-phase residential electrical service. Confirm your building has three-phase service and the correct amperage capacity before ordering this unit.
What does EER mean and is 13.7 EER good for a water source heat pump?
EER measures cooling efficiency at a single operating point — higher is better. A 13.7 EER rating is solid for a 10-ton commercial water source heat pump, meaning the unit produces 13.7 BTUs of cooling for every watt of electricity consumed under rated conditions. It reflects efficient performance for a commercial unit of this size.
What is a left return back supply water source heat pump used for?
Left return / back supply describes the direction air enters and exits the horizontal cabinet. Left return means return air enters from the left side; back supply means conditioned air exits from the back of the unit. This orientation fits specific drop-ceiling or plenum duct configurations common in commercial corridor and office installations.
Does a water source heat pump need a cooling tower?
Yes. A water source heat pump like the MBB120AKCN0E01S transfers heat to a shared water loop, and that loop needs a cooling tower (or fluid cooler) to reject heat in summer and a boiler to add heat in winter. The unit does not include loop equipment — that's part of the building's central plant.
How many tons is the Comfort-aire MBB120AKCN0E01S?
The Comfort-aire MBB120AKCN0E01S is a 10-ton unit — 120,000 BTU/h nominal capacity. It is one of the larger single water source heat pump package units available and is designed for commercial applications, not residential use.
