# Compare temperatures from different sensors

**URL:** <https://community.homey.app/t/compare-temperatures-from-different-sensors/50360>\
**Category:** Questions & Help\
**Tags:** app\
**Created:** [August 12, 2021, 9:57am UTC](https://community.homey.app/t/compare-temperatures-from-different-sensors/50360 "2021-08-12T09:57:29Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Fekik](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/fekik/32/34271_2.png) [@Fekik](https://community.homey.app/u/Fekik)\
**Post date:** [August 12, 2021, 9:57am UTC](https://community.homey.app/t/compare-temperatures-from-different-sensors/50360/1 "2021-08-12T09:57:30Z")

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Hi,  
I want to turn on my AC. It should be something like this: When temperature oustide is larger that temperature inside, my AC turns on (or blings go down, etc.).

I have temperature sensor outside, I have temperature sensors in each room.

How do you think I can get variable as a temperature from outside sensor? then I can compare it to the temperature with sensor inside.

Is there maybe any other way?

Thanks!

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**Author:** ![Peter\_Kawa](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/peter_kawa/32/173848_2.png) [@Peter\_Kawa](https://community.homey.app/u/Peter_Kawa)\
**Post date:** [August 12, 2021, 10:55am UTC](https://community.homey.app/t/compare-temperatures-from-different-sensors/50360/2 "2021-08-12T10:55:32Z")

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You could do something like this:  
Use a logics card “if calculation is true” as a condition.  
**IF** outside temp exceeds 20°C  
**AND** tag [outside temperature] is equal to or is higher than tag [inside temperature]  
**THEN** switch AC on

The logics card (it’s rather confusing you can’t see to which device the tags belong if the tags are named alike):

 ![Screenshot_20210812-123247_Homey](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/6/b/6b528488a2e2df3d2b7f4ace6b7cc5cf85645aaa.jpeg)

The first [temperature] tag is this one (weather app temperature):

 ![Screenshot_20210812-123328_Homey](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/3/9/39a02c89d7cbd3cd1fefb332732fc1e76d8aa86a.jpeg)

The second [temperature] tag is this one (thermostat measured temperature) :

 ![Screenshot_20210812-123210_Homey](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/e/9/e931a1362a795288815128ccf9681de6dd39523a.jpeg)

Timeline after pushing flow test button:

 ![Screenshot_20210812-130031_Homey](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/f/8/f81f8f98db7f794d819eac4ecf41a3d9a5ce68eb.jpeg)  
AC not switched on, while inside temp exceeds outside temp.

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<div class="post-metadata">

**Author:** ![Fekik](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/fekik/32/34271_2.png) [@Fekik](https://community.homey.app/u/Fekik)\
**Post date:** [January 21, 2022, 4:09pm UTC](https://community.homey.app/t/compare-temperatures-from-different-sensors/50360/3 "2022-01-21T16:09:02Z")

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Thank you, I will try your tip in the summer 🙂