# differentials

**URL:** <https://forum.nachi.org/t/differentials/179580>\
**Category:** Public Archive\
**Created:** [October 24, 2004, 12:00am UTC](https://forum.nachi.org/t/differentials/179580 "2004-10-24T00:00:00Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![system](https://global.discourse-cdn.com/internachi/original/3X/d/f/df7ced6a9ca05e7c93fa949dfc12a8c10d06c887.png) [@system](https://forum.nachi.org/u/system)\
**Post date:** [October 24, 2004, 12:00am UTC](https://forum.nachi.org/t/differentials/179580/1 "2004-10-24T00:00:00Z")

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**Originally Posted By: mtimpani**  
**This post was automatically imported from our archived forum.**

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I know to do temp differentials on ac, but do we ever do them on heat? If we do what are the parameters?  

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**Author:** ![system](https://global.discourse-cdn.com/internachi/original/3X/d/f/df7ced6a9ca05e7c93fa949dfc12a8c10d06c887.png) [@system](https://forum.nachi.org/u/system)\
**Post date:** [October 27, 2004, 12:00am UTC](https://forum.nachi.org/t/differentials/179580/2 "2004-10-27T00:00:00Z")

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**Originally Posted By: tallen**  
**This post was automatically imported from our archived forum.**

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Dave bush wrote:  
  
  

| **Quote:** |
| Mark, there is not a temperature differential, I just take the output temperature at the vent registers. The temperature measured at the output for forced air systems should be as follows:  
ELECTRIC FORCED AIR HEAT = 85 - 105 degrees F  
FUEL FORCED AIR HEAT = 105 - 145 degrees F  
HEAT PUMP FORCED AIR HEAT = 80 - 90 degrees F  
 |

  

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