Crestron thermostats and climate control

Which Crestron thermostat do I need?

Start with the heating or cooling system and decide whether you want a thermostat on the wall or the controls out of sight in an equipment cabinet.

• HZ-THSTAT: the Horizon wall thermostat, with a 3.5 in. touch screen, built-in humidity sensing and a Wi-Fi link to the control system. It runs forced air, heat pump, 2-pipe and 4-pipe fan coil and radiant floor systems.
• CHV-THSTAT-PIR-10: a wall thermostat with 0-10V or relay outputs and a built-in occupancy sensor, suited to hotels and apartments.
• CHV-TSTAT-FCU-PIR-10: a 0-10V fan coil thermostat that detects vacant rooms to save energy.
• DIN-1TSTAT8: eight zones of radiators or underfloor heating from one DIN rail module, with a small sensor in each zone instead of a wall thermostat.
• DIN-THSTAT: heating, cooling and humidity control from a DIN rail, reading remote sensors in the room.
• DIN-TSTAT-FCU: a two-pipe fan coil controller with Cresnet, RS-485, Modbus and BACnet.

Which remote temperature sensor should I use?

Remote sensors let a DIN rail thermostat, or a wall thermostat in an awkward spot, read the temperature where people actually are.

• CHV-RTS and CHV-RTHS: discreet round sensors, 39 mm across, that sit about 3 mm proud of the wall and can be painted or wallpapered. The CHV-RTHS adds humidity. The MMK-RS kit, sold separately, allows a fully flush finish in new builds.
• CHVI-RTS-1G-N: fits a 1-gang box and takes an FP INTENSE or FP PURE faceplate, sold separately, to match the switches in the room.
• CHVI-RTS-1G-SM: surface mounts over a 25 mm hole with no back box, or over a 1-gang box.
• CHV-RSS: sealed in a waterproof stainless steel sleeve for a concrete slab, under a floor or outdoors.
• C2N-RTHS: reports temperature and humidity straight to the control system over Cresnet.

The thermostat-connected sensors use a single twisted pair and can be up to 152 m away on CAT5 or similar low-capacitance cable.

How do thermostats fit into a Crestron system?

Wall thermostats such as the CHV-THSTAT-PIR-10 connect to the control processor over Cresnet, while the HZ-THSTAT uses Wi-Fi. Once connected, setpoints, modes and schedules can be set from touch screens, remotes and the mobile app, alongside lighting and shades. The HZ-THSTAT also reports the outdoor temperature, weather conditions and the week's forecast.

The DIN-THSTAT and DIN-1TSTAT8 fit a 35 mm rail in a DIN-EN series or similar enclosure and take their power from Cresnet: 3 W for the DIN-THSTAT and 6 W for the DIN-1TSTAT8. Both take 9 DIN module spaces (162 mm). The DIN-1TSTAT8 needs a Crestron control system to work, stores setpoints in its own memory and falls back to a failsafe temperature, 20 °C by default, if a user setpoint is lost.

In commercial buildings, the DIN-TSTAT-FCU can run standalone or report to a building management system over Modbus or BACnet as well as to a Crestron processor. The CHV-THSTAT-PIR-10 and CHV-TSTAT-FCU-PIR-10 wall thermostats are also fully functional on their own, without a Cresnet connection.

What should I check when replacing a thermostat?

• System type: confirm the heating and cooling system (conventional, heat pump, fan coil, radiant) and whether the outputs are relays or 0-10V.
• Power: the HZ-THSTAT runs on 24 VAC from the HVAC system. The CHV-THSTAT-PIR-10 and CHV-TSTAT-FCU-PIR-10 need 24VDC from Cresnet and 24VAC from the HVAC unit. The DIN-TSTAT-FCU is line powered at 230 V AC.
• Common wire: if an HZ-THSTAT is going where there is no common wire, add the HZA-CONV-THSTAT-2WIRE adapter, which works with as few as two wires.
• Relay ratings: check the loads against the thermostat, for example 1 A each and 3 A in total on the HZ-THSTAT.
• Finish: the HZ-THSTAT comes in almond, black or white, and the CHV-THSTAT-PIR-10 in black or white textured.
• Settings: the HZ-THSTAT can have its configuration created and loaded onto several units at once with the Thermostat Configuration Tool in Crestron Toolbox.