Smart heating based on electricity spot prices

In the Evesta app, you can select the required temperature and define how much the temperature setpoint may be increased during cheaper periods or reduced when electricity is more expensive.

The system can preheat a floor, room or hot-water cylinder when electricity is cheaper and reduce heating during expensive periods. Absolute electricity price limits can also be configured.

The thermostat supports both 15-minute and 60-minute spot-price intervals when the Evesta app and device firmware are up to date.

Actual savings depend on electricity price fluctuations, the thermal storage capacity of the building or water heater, heating power, insulation, selected temperature limits and user requirements.

Suitable for use without a spot-price electricity contract

Electricity price optimisation is optional. The Caladrius T1 can also operate as a conventional Wi-Fi thermostat using temperature control and schedules.

Available operating modes include:

• Home;
• Away;
• Weekly Schedule;
• Antifrost;
• Power Regulation;
• heating or cooling control.

The thermostat can therefore also be used when the electricity contract is not based on spot prices.

Typical applications

The Evesta Caladrius T1 can be used for controlling:

• electric underfloor heating;
• electric heating cables;
• electric water heaters and hot-water cylinders equipped with a suitable temperature sensor;
• electric heating in homes, cottages and technical rooms;
• other compatible single-phase resistive heating loads.

For loads exceeding the thermostat’s rating, three-phase systems or unsuitable load types, an appropriately rated contactor or another suitable control solution must be used.

Main features

• smart single-phase DIN rail thermostat;
• electricity spot-price optimisation;
• support for 15- and 60-minute price intervals;
• absolute electricity price limits;
• control through the Evesta mobile app;
• remote access over the internet;
• 2.4 GHz Wi-Fi connection;
• temperature-based heating control;
• weekly schedules and operating modes;
• potential-free relay output;
• maximum resistive load of 1 × 16 A;
• supplied with a 10 kΩ NTC temperature sensor;
• compatible with several commonly used NTC sensor types;
• DIN rail mounting in an electrical cabinet or suitable enclosure.

Technical specifications

• Brand: Evesta
• Model: Caladrius T1
• Product type: single-phase DIN rail Wi-Fi thermostat
• Supply voltage: 230 VAC, 50/60 Hz
• Maximum load: 1 × 16 A, resistive load
• Relay output: potential-free contact
• Wi-Fi: 2.4 GHz, IEEE 802.11 b/g/n
• Ambient operating temperature: 0 to +30 °C
• Temperature adjustment range: +5 to +90 °C
• Included sensor: 10 kΩ NTC floor or external temperature sensor
• Supported sensor values: 6.8, 10, 12, 15, 33, 47 and 100 kΩ NTC
• Mounting: standard DIN rail
• Permitted pollution degree: 2
• Standards: CE, EN 60730-1 and EN 300 328 V2.2.2
• Service provider: SpotNRG Oy
• Equipment manufacturer: Ouman Oy, Finland

Installation and important information

Installation and electrical connection must only be carried out by an authorised electrician in accordance with the supplied wiring diagram and applicable electrical regulations.

The maximum rating of 16 A applies to a resistive load. A suitable contactor or alternative control solution may be required for higher loads, three-phase systems and inductive or capacitive loads.

A Wi-Fi connection, the Evesta mobile app and access to the Evesta cloud service are required for remote control and electricity spot-price optimisation.