App to control garage vent fan based on temperature delta?

SmartApps & Automations Automation Ideas
1

I want to turn on my garage vent only when the inside temperature is above a threshold and it is hotter than outside by a selected delta.
I found an old thread where this had been done with IDE. Has anyone done this with the new architecture?

Old thread:

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Might be able to do it with the Rules API and a temperature triggered switch. @TapioX is the Rules API wizard and can probably provide some insight.

Can’t be done with native ST Routines because there is no way to do comparisons.

The Text/Number Edge driver from @Mariano_Colmenarejo allows for number comparisons and when used with the Rules API might be able to achieve what you want, but not sure how to grab the outside temp for the comparison.

1 Like
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@TheVeryFirstLAD
Using this Rules API rule example is possible to calculate temperature difference.

I think that all other can be done using ST App Routines.