How do you set an AND function in the Rule Machine 4.1

alansanderson25 · June 2, 2021, 4:35pm

I am trying to set up a whole house attic fan Rule. I need it to turn on at sunset and if the Master Bedroom temp is > then the outdoor temp, It looks like the triggers default to OR I Need both triggers to be true.

Or do I need multiple separate rules?

One to turn it on at sunset.
Another to turn it off if the Master Bedroom temp is < then outdoor temp

And then one more to turn it on at sunrise for a early morning cool down?

waffles · June 2, 2021, 4:40pm

There may be a more elegant way of doing this, but what I do is 2 seperate rules.

Rule 1, trigger=sunset, but add a condition that says if bedroom temp is <
Rule 2, trigger=Bedroom temp >, and a condition that says between sunset and sunrise

thebearmay · June 2, 2021, 4:41pm

Trigger: Sunset or Sunrise
Condition: Bedroom Temp > Outdoor Temp
Action: Turn on Fan

alansanderson25 · June 2, 2021, 4:57pm

OK so not multiple triggers. Thanks

terminal3 · June 2, 2021, 4:58pm

I would go with one rule:

trigger = sunset

If bedroom temp > outdoor then

    turn on vent

    wait for condition bedroom temp < outdoor temp or sunrise
    (or whatever time you want it to stop checking)

    Turn off vent
 END IF

stephen_nutt · June 2, 2021, 5:19pm

Triggers cannot ever be AND because they are events and both won't happen at the exact same instant in time. You can use OR with multiple triggers and then use a Conditional for other device for it's state. This gets a lot of people.

alansanderson25 · June 3, 2021, 3:33pm

OK Thanks to all for the advice.

I have the following which should work. I want the fan to cycle on and off. So that the upper floor stays as cool as possible, then shut off at a fixed time. I have a similar rule for sunrise to do a morning cool down. The basement temp probe is moved out to the front porch for the summer.