Nest thermostats are not directly compatible with Mitsubishi mini-splits due to the proprietary 2-wire interface used by Mitsubishi systems. However, there are workarounds to integrate Nest thermostats with Mitsubishi mini-splits, which require some technical knowledge and modifications to the system.
Mitsubishi PAC-US444CN-1 Thermostat Interface
One solution to integrate Nest thermostats with Mitsubishi mini-splits is to use the Mitsubishi PAC-US444CN-1 thermostat interface. This interface can be connected to the Nest thermostat using resistors to resolve constant activation issues.
Technical Specifications
- The PAC-US444CN-1 is a 2-wire interface that connects the Nest thermostat to the Mitsubishi mini-split system.
- It requires a 24VAC power supply, which can be obtained from the mini-split’s control board or a separate transformer.
- The interface uses resistors to translate the Nest’s control signals to the proprietary 2-wire protocol used by Mitsubishi.
- It supports basic functions like temperature control, mode selection, and fan speed adjustment.
Installation Process
- Locate the indoor unit’s control board and identify the 2-wire terminal connections.
- Mount the PAC-US444CN-1 interface near the indoor unit, ensuring it is within the wiring distance.
- Connect the 2-wire terminals on the interface to the corresponding terminals on the indoor unit’s control board.
- Connect the 24VAC power supply to the interface.
- Install the Nest thermostat in the desired location and connect it to the PAC-US444CN-1 interface using the appropriate wiring.
- Configure the Nest thermostat to work with the Mitsubishi mini-split system.
This method requires some technical knowledge and modifications to the system, but it can provide a way to integrate Nest thermostats with Mitsubishi mini-splits.
Third-Party Interfaces
Image source: Mitsubishi ac By Dinkun Chen
Another solution to integrate Nest thermostats with Mitsubishi mini-splits is to use a third-party interface, such as the Flair Puck.
Flair Puck
The Flair Puck is a smart home device that acts as an intermediary between the Nest thermostat and the Mitsubishi mini-split system.
Features
- Connects to the Mitsubishi mini-split via IR commands, allowing for integration with the proprietary system.
- Integrates with smart home platforms like SmartThings, allowing for voice control and automation.
- Provides temperature and humidity monitoring, as well as control over the mini-split’s functions.
- Requires a separate Flair app for configuration and control.
Installation Process
- Mount the Flair Puck near the Mitsubishi mini-split indoor unit, ensuring it has a clear line of sight to the IR receiver.
- Connect the Flair Puck to your home’s Wi-Fi network.
- Install the Flair app on your mobile device and follow the on-screen instructions to connect the Puck to your Nest thermostat and Mitsubishi mini-split.
- Configure the Flair Puck to control the Mitsubishi mini-split’s functions, such as temperature, mode, and fan speed.
The Flair Puck provides a more seamless integration between the Nest thermostat and the Mitsubishi mini-split, but it requires an additional device and a separate app for control.
Considerations
It is important to note that using a Nest thermostat with a Mitsubishi mini-split may result in the loss of some efficiency features that make mini-splits great. Additionally, replacing a proprietary Mitsubishi thermostat with a Nest thermostat may cost more money in energy and repairs due to the loss of software that makes the unit more efficient.
Therefore, it is recommended to use a proprietary controller, such as Mitsubishi’s controller, to run the heat pump, and a separate dehumidistat to control the dehumidifier. This method ensures good inverter control and prevents damage to the system.
Conclusion
While it is possible to integrate Nest thermostats with Mitsubishi mini-splits, it requires some technical knowledge and modifications to the system. Using a proprietary controller and a separate dehumidistat is the recommended solution to ensure good inverter control and prevent damage to the system.
References:
– Connecting my Mitsubishi mini-split and Nest
– Nest compatibility with Mitsubishi
– Nest Pro Support: Mitsubishi Integration
– Is a Nest the best way to control a Mitsubishi heat pump and dehumidifier?
– Nest Thermostat and Mitsubishi Mini Split Integration