Nest Gen3 Thermostat (U.S version) general requirements
- Nest Thermostats are designed to work with 24V US spec AC systems. They require installation of a conversion kit as well as bypassing of PCB in order for them to work with 220V UAE AC systems
- Nest Thermostats can be retrofitted to work on single and 3 fan speed modes
- Single fan speed mode requires the presence of 4 wires to thermostat location
- Three fan speed mode requires the presence of 6 wires
- Thermostat locations with 3 wires, requires the installation of an additional wire saver module to add the 4th wire for single fan speed.
- Less than 6 wires at a thermostat location requires the pulling of a new set of 6 wire panel cables for three fan speed activation.
Non-compatibility: cases where Nest cannot be installed
- AC units with inverter compressor or DC current fan motor (solutions for LG, OGeneral and Mitsubishi ACs using bespoke interface are available)
- Window type AC units
- VRV type ACs
- Where ACs are connected to a BMS or wired smart home system
- Chilled water systems with modulating actuator motor (1-10v)
- UK and European spec Nest thermostats are designed to work with boilers and water heaters and are not configured to work with AC systems
Specific compatibility guidelines
- As a general rule, apartments located within towers are typically served by a central chiller, as such would have 6 wires
- In some newly build apartments with modulating actuator motors, there would a requirement to replace actuator motors with standard on/off models. This can only be established post inspection. Cost of actuators motors varies between AED 350-500 per unit. In very rare cases, valve assembly would also have to be replaced (cost AED 1500 per unit)
- AC units within areas with district cooling such as the Palm, Jumeirah Islands, JLT, Motor City and Sports City would have thermostats with 6 wires
Villas: (in non district cooling areas)
- Found in majority of Emaar villas across Springs, Meadows and Arabian Ranches as well as Al Furjan
- All units have 3 wires to thermostat location
- Requires installation of an additional module (add 4th wire) for single fan speed
- Three fan speed requires pulling of 6 wires. Smaller capacity units have single stage fan that requires installation of fan transformer (AED 390)
- New LG ACs with modulating compressor and DC fan motor. Require installation of a bespoke Nest interface/module approx cost (AED 660) per module
- Found in many Emaar villa communities.
- All units have 3 wires to thermostat
- Requires installation of an additional module for single fan speed.
- Three fan speed requires pulling of 6 wires
- New OGeneral ACs with modulating compressor and DC fan motor. Require installation of a bespoke Nest interface/module approx cost (AED 850) per module
c) York & Daikin:
- Both York and Daikin units would have 4 wires through to thermostat location
- York prevalent in The Villa project. Daikin is installed in all Arabian Ranches 2 communities
- Older units would have 8 wires through to thermostat location
- Newer units with LCD type thermostat would have 2 wires going to thermostat location
- Prevalent in Jumeirah Park and other Nakheel communities
- Mexican spec : 4 wires
- Egyptian spec: 5 wires (found in Damac Hills), requires wire saver for 3 fan speed.
- Egyptian spec: 4 wires (found in Arabella Mudon), ACs would have DC fan units. Requires bespoke interface.
e) Rheem : 6 wires found in Mira and 5 wires found in Lantana
f) American breeze: 6 wires found in some older Emaar villas in Meadows and Lakes as well as Jumeirah Islands
g) Mitsubishi: All Mitsubishi units require pulling of new wires as well as installation of an interface (provided CN90 connector is present on PCB). Found in older villas of non-free hold communities
h) Honeywell: Very rarely installed in villas. Would typically have 6 wires
i) Siemens: 7 or 8 wires, found in some Jumeirah Park villas