Greenhouse window ventilation automation

1

I am working on an automation for a powered ventilation window in a greenhouse.
The trigger is a temperature sensor inside and outside,
the action the opening or closing of the windows.
The windows motor is giving feedback on it’s position,
so I can adjust the windows% opening on the temperature difference.
Does anybody know where to find the right script or add-ons?
I have looked under the topic Covers as that is it is the closest sollution to this topic.
But i cannot find there what I’m looking for

Mark

2

I am trying to do the same thing.
Did you have any joy?

3

No, and the project has, for now, been transfered to a very simple open and shut system. If you do have a nice script, let me know

4

No, I too an planning more simple: open/close vent by activating a relay for 12sec to open and reverse to close. I’m looking into on_value_range from an internal temporature sensor as the triggers. Just to open if temp goes above threshold and close when it drops below. IS that how you are doing it?

5

An intelligent system is needed that analyzes many variables.
To do this, you will first have to determine a set temperature at which you want inside to be.
Starting from the temperature difference between inside and my setpoint, I have determined different states in integers and strings:
2,1,0,-1,-2 which would be very cold, cold, inrange, hot and very hot. That is the DEMAND for heat inside.

- platform: template
  sensors:
    sensor_demanda_sala:
      friendly_name: "Demanda Sala"
      value_template: >-
          {% set consigna = states('sensor.sensor_consigna_sala') | float(0)  %}
          {% set sala = states('sensor.temperatura_sala') | float(0)  %}
          {% set demanda = states('input_number.diferencia_demanda') | int | round  %}
          {% set altaDemanda = states('input_number.diferencia_alta_demanda') | int | round  %}
          
            {% if sala - consigna < demanda and consigna - sala < demanda %}
                IN RANGE
            {% elif sala - consigna > demanda and sala - consigna < altaDemanda %}
                FRED (cold)
            {% elif consigna - sala > demanda and consigna - sala < altaDemanda %}
                CALOR (hot)
            {% elif sala - consigna > altaDemanda %}
                MOLT FRED
            {% elif consigna - sala > altaDemanda %}
                MOLTA CALOR    
            {% else %}
                DESCONEGUT
            {% endif %}
    sensor_numeric_demanda:
      friendly_name: "Estat Numeric Demanda"
      value_template: >-
            {% if is_state('sensor.sensor_demanda_sala', 'IN RANGE') %}
                0
            {% elif is_state('sensor.sensor_demanda_sala', 'FRED') %}
                1
            {% elif is_state('sensor.sensor_demanda_sala', 'MOLT FRED') %}
                2
            {% elif is_state('sensor.sensor_demanda_sala', 'CALOR') %}
                -1
            {% elif is_state('sensor.sensor_demanda_sala', 'MOLTA CALOR') %}
                -2
            {% elif is_state('sensor.sensor_demanda_sala', 'DESCONEGUT') %}
                5
            {% else %}
                6
            {% endif %}

With two input_number I can control the temperature difference between demand and high demand, that would be the hysteresis.
imagen

Then we have the DEMAND, which we obtain from the difference between the setpoint and the interior, and we can see if the temperature outside suits us or not.
My system is more complex, I have more variables and I work with temperature differences, is not the same case but i hope it helps you. I wrote this to implement later:

IF	DEMANDA	<0 (hot)	
                        IF	dif_comporta	>	dif_demanda_comporta	--> up
			            ELSE	dif_comporta	<	dif_demanda_comporta	--> down
							
IF	DEMANDA	>0 (cold)	
                        IF	dif_comporta	<	dif_demanda_comporta	--> up
			            ELSE	dif_comporta	>	dif_demanda_comporta	--> down
ELSE	up

There may be other factors such as humidity or the desire to ventilate with a timer that could be incorporated into the automation. These aspects are when it can be counterproductive if, for example, there is a lot of humidity outside and you do not want it inside or if you have scheduled an opening when you have a demand for heat inside and it is very cold outside.
Other factors can be cold/hot production equipments or the speed of the air injection.

Then maybe you can use grafana to analyze how is working and if there are some moments where you would prefer another state in the window.

imagen