Mitsubishi In-Ceiling Heat Pump Systems in San Francisco

Completed October 10, 2026

Two Mitsubishi M-Series heat pump systems installed to provide in-ceiling heating and cooling for a four-story San Francisco home with radiant heat.

Installation of two Mitsubishi Electric M-Series heat pump systems for a four-story San Francisco home with existing radiant heat. The project was designed to add in-ceiling heating and cooling without relying on a conventional ducted HVAC system, with both outdoor units installed on the rooftop.

Project details

Customer problem

The home was built in the 1950s and uses radiant heat, with no conventional central air conditioning system. The homeowner wanted to add A/C using in-ceiling mini-split equipment, initially focusing on the upper two floors with the possibility of extending conditioning to the lower levels.

Previous system

Radiant heating system with no conventional central air conditioning.

Recommendation and why

Mitsubishi M-Series inverter heat pump systems with in-ceiling indoor units were selected to add zoned heating and cooling while minimizing the need for extensive conventional ductwork in the four-story home.

Installation challenges and work performed

Installed two Mitsubishi outdoor heat pump units on the rooftop and connected them to the in-ceiling indoor equipment. Completed the required refrigerant and electrical connections, performed nitrogen pressure testing, and evacuated the refrigerant circuits to a deep vacuum before startup.

Equipment details

Mitsubishi Electric M-Series systems consisting of an MXZ-2D20NL multi-zone heat pump with 20,000 BTU/h capacity and a SUZ-AA18NL heat pump with 18,000 BTU/h capacity. Both systems use inverter-driven variable-capacity technology and have rated outdoor sound levels of approximately 55 dB(A).

Observed result

Completed rooftop installation of both Mitsubishi heat pump systems, providing the home with new in-ceiling heating and cooling capability while retaining the existing radiant heating system.