I operate a data-center in a climate where there is occasionally cool air outside. We have z-wave relays that can control several ventilation fans that can move hot air out of our server space, and move outdoor air into our space.
Today I have a scene that shuts off the intakes an hour after sunrise, and if we think it’s going to be cold enough overnight to use outdoor air, then we turn it on manually (remotely at least).
But I would like to make that automatic.
To complicate things, the decision on weather outdoor air is useful to us depends on the temperature of the air indoors. Basically it has to be about 15 degrees colder outside than it is inside for it to be worth it.
We have an array of z-wave temp sensors indoors in different locations, and we have a ‘virtual outdoor temp sensor’ plugin installed, as well as vera itself displays’ the outdoor temp. So the information is in vera for us to make that decision manually.
How should we go about scripting the vera to compare temps, and send commands to z-wave relays in response?
Time of day isn’t strictly speaking relevant other than the 15 degrees rule applies less when the sun is down. (the intake ducting gets hot in the sun if you are curious)