Carrier 40mhhq18---3 Ductless High Wall Heat Pump 18000 Btu/h

Product Description

The CARRIER 40mhhq18---3 is an 18,000 BTU/h ductless high wall indoor fan coil unit designed for heat pump operation in single-phase, 208-230 volt, 60 Hz systems. Rated at 1.5 tons nominal capacity, it delivers both cooling and heating without requiring ductwork. The unit uses an ECM blower motor running at four speeds up to 1,150 RPM, with airflow ranging from 353 to 559 CFM. It achieves an EER of 11.2 and a SEER range of 19-23, making it a competent performer for retrofit and add-on applications. The unit is ETL Listed and operates on R-410A refrigerant. Licensed HVAC technicians perform installation and commissioning.

This fan coil is intended for residential and light commercial applications where conventional ducted systems are impractical or unavailable. Common install scenarios include room additions, office buildouts, spaces served by hydronic or electric heat with no existing ductwork, and historical renovations where preserving the original structure rules out duct installation. The unit mounts on the wall near the ceiling and connects to a matched outdoor condensing unit via refrigerant tubing and low-voltage wiring. Multi-zone configurations are supported, allowing this indoor unit to be paired with compatible multi-zone outdoor units.

Key Features

• 18,000 BTU/h cooling and heating capacity at 1.5 tons nominal
• ECM blower motor with four speeds and 1,150 RPM rating for quiet, efficient airflow
• SEER rating of 19-23 and EER of 11.2 for energy-efficient operation
• Sound level of 34-46 dBA for low-noise indoor comfort
• R-410A refrigerant with flare fittings on both liquid and suction lines
• Multi-zone compatible for use in multi-split system configurations
• ETL Listed for safety compliance

Compatibility

The 40mhhq18---3 is part of the 40MHH product family and is designed as a matched indoor fan coil for use with a compatible CARRIER, Bryant, or Payne outdoor condensing unit in a ductless mini-split or multi-zone heat pump system. Verify outdoor unit compatibility using the applicable engineering guide before installation.

Installation Notes

Installation must be performed by a licensed HVAC technician holding EPA Section 608 certification for R-410A refrigerant handling. Power down and lock out the electrical circuit before any wiring work. The wall-mount bracket must be secured to structural framing capable of supporting the unit weight of 31.97 pounds plus vibration loads. Refrigerant line connections use flare fittings on both the 1/4 inch OD liquid line and the 1/2 inch OD suction line; pressure-test and evacuate the line set before charging per manufacturer specifications.