RECUBOX and integration into a smart home

1. FAQ section rekupex.cz – Simple description:

How to connect the RECUBOX heat recovery unit to the LOXONE smart home?

The RECUBOX unit can be easily integrated into the LOXONE smart home. This gives you full control over the ventilation in your home - manually, time-based and automatically based on air quality.

Guiding principle:

• EC fans (exhaust and supply) are controlled by a 0–10 V signal, which allows for continuous power regulation.

• The BY-PASS damper (optional equipment of RECUBOX) is controlled by a servo drive , which opens or closes the exchanger bypass.

• Control is done from the Loxone Miniserver , ideally using the Analog Output module .

• Temperature and CO₂ sensors can automatically change ventilation power and heat recovery mode.

• Frost protection is provided either by opening the by-pass, switching off the fans, temporarily stopping the heat recovery or starting the optional preheating .

This proposal is only a suggestion for a possible solution and must be consulted with a certified LOXONE specialist.

2. Advanced design: Complex connection of RECUBOX + LOXONE

System components:

From rekupex.cz:

• RECUBOX heat recovery unit

• 2× EC fan (supply + exhaust), controlled 0–10V

• By-pass damper with 24V actuator (ON/OFF or analog control)

• Temperature sensors (NTC/PT1000/analog output)

• CO₂ sensors with 0–10 V output or digital output

• Preheating (optional) – for example, an electric air heater

FROM LOXONE:

• Miniserver Gen 2 (main control unit)

• Analog output module (AO Extension) – for 0–10 V control

• Relay Extension – for switching preheating and servo drive

• AI Extension – for reading analog values (temperature, CO₂)

• Loxone Touch or Loxone App – for control and visualization

System logic:

EC fan control:

• Both fans are controlled by a 0-10 V output from Loxone.

• The power can be set:

  • Manual control in the app

  • By schedule (e.g. night/day/weekend)

  • Automatic according to CO₂ or humidity

Bypass function:

• Controlled by a servo drive via relay output or 0–10 V (depending on servo type).

• Switching to summer mode:

  • Outdoor temperature < indoor (e.g. 20 °C vs. 24 °C)

  • Loxone opens the by-pass and bypasses the exchanger → direct ventilation

Anti-freeze protection:

• Monitors the temperature at the exhaust air outlet.

• If the temperature drops below 1°C, Loxone:

  1. Opens the by-pass flap – preheats the exchanger with indoor air

  2. Or it stops the supply fan – it reduces the cooling of the exchanger

  3. Or turn off the ventilation for a short timeat the time

  4. Or start preheating (e.g. electric)

• As soon as the outlet temperature rises (e.g. to 3 °C), the mode returns to normal.

CO₂ control:

• The CO₂ sensor sends an analog signal to Loxone (e.g. 0–10 V = 400–2000 ppm).

• When the threshold is exceeded (e.g. 900 ppm) , the ventilation power is increased automatically.

Visualization and control:

• In the Loxone app, the user selects the mode: "AUTO - DAY - NIGHT - VENTILATION - HOLIDAY"

• Can monitor:

  • System temperatures

  • CO₂ level

  • Recuperation and bypass status

• Possibility of notification of the need to replace filters (optionally with differential pressure)

Wiring diagram (text form):

Final notes:

• All logic is created in the Loxone Config environment - PID blocks, state machines, comparators and timers.

• It is recommended to add protection against sensor errors and overvoltage.

• The advantage of this solution is high flexibility, low consumption and full automation of ventilation.

This solution proposal is only indicative and must always be consulted and adapted to the specific installation together with a certified Loxone specialist.