# Daikin 9kW ASHP application discussion

**URL:** <https://community.openenergymonitor.org/t/daikin-9kw-ashp-application-discussion/24848>\
**Category:** Heatpump\
**Created:** [21 November 2023 17:55 UTC](https://community.openenergymonitor.org/t/daikin-9kw-ashp-application-discussion/24848 "2023-11-21T17:55:22Z")\
**Posts on this page:** 1\
**Showing post:** 203

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**Author:** ![tiger\_cook](https://community.openenergymonitor.org/user_avatar/community.openenergymonitor.org/tiger_cook/32/27858_2.png) [@tiger\_cook](https://community.openenergymonitor.org/u/tiger_cook)\
**Post date:** [19 January 2024 09:44 UTC](https://community.openenergymonitor.org/t/daikin-9kw-ashp-application-discussion/24848/203 "2024-01-19T09:44:42Z")

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> [@Timbones](#):
>
> The primary pump is coming on periodically to “sample” the water temperature, and flow is _lower_ than return, resulting in negative heat (cooling). We’ve seen this on someone else’s system when discussing which RT to pull from their heat pump. I would expect to see flow and return being the same at the end of each pump run. You may need to run experiments with longer pump runs to calibrate the sensors.

This maybe an ESPAltherma & Home Assistant polling/template out-of-sync issue - ESPAltherma every 30 or so seconds from the HP, vs the sub-second power draw values from your external CT clamp when calculating the COP, could you filter out negative values via a template before sending to OpenEnergyMonitor?

> [@Daikin Altherma, ESPAltherma & Home Assistant with OpenEnergyMonitor](https://community.openenergymonitor.org/t/daikin-altherma-espaltherma-home-assistant-with-openenergymonitor/25057/52):
>
> I think, I nailed it, it’s a bit crude - I created another template that listens to the original COP sensor template, If the new ‘cop\_true’ template value is in between 0 and 8 that listens to the original COP sensor, log value, otherwise log 0 (no negative or uber efficiency values). I hope this makes sense. Thoughts on my cowboy approach welcome blush - name: "cop\_true" unique\_id: "cop\_true" unit\_of\_measurement: 'COP' state: \> {% set cop\_true = (states('sensor.cop\_power') | fl…

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