Custom Dashboard: post processing data feeds

Hi everyone,

I am trying to show the daily COP and weekly COP for my HP monitoring dashboard:


I realised however that I can only use feed values on the dashboard so I need to do the processing on the feeds first. However, I only have access to emoncms.org and I don’t think I am able to create virtual feeds. Therefore, I had a few questions about how the feed processes work:

  • If I apply multiple processes to an input and use log to feed. Does that mean the following step has the input raw value again? eg I use log to feed, then I multiply that value by 0.001 and then use log to feed again.

  • How can I use the power to kWh/d for a pulse reading? Is there another way to create a daily cumulative feed?
    This is what I have done so far:

  • If I want to divide a feed by another feed (i.e., the daily heat by the daily electricity use) how can I use the processes to achieve this? This is what I have tried but the power to kWh/d output is not passed to the next step…(hence why is diving the raw value by the feed i think). I have a similar issue if I try to do COP of the instantaneous feeds (the electricity value has to be Wh since is a pulse meter reading and if i use power to Wh for the heat reading it is not passed on to the next step therefore I can’t divide it by the electricity feed).

Thanks a lot in advance! :smiley:

Hello @Rolop, have you considered using the heat pump dashboard in the Apps module?

You can use your cumulative kWh feeds for that and it will calculate the daily COP for you.

I don’t think its possible to do it otherwise, unfortunately.

1 Like

Hello @TrystanLea, thank you for clearing that up. I was playing with the custom dashboard until I had the CT sensors set up. Would you be able to clarify for me why the outside temperature feed is required for the heat pump app?

With regards to the CT sensor I was comparing the graph I am getting with the instantaneous energy reading of the heat pump:


Am I correct saying that the CT sensor reading is in Watts?

Thank you very much for your help!
Rocio

Hello @Rolop, interesting, how are you measuring electrical consumption? is it an emontx or emonpi?
Looks like a fairly low resolution from the heat meter readings. Is it a hot water heat up period 12 to 12:30?

The outside temperature feed is optional in the heat pump app, or at least it should be…

Hello @TrystanLea, electrical consumption is being measured via a CT sensor connected to an emonpi. There are no specific heating periods for the heat pump as it operates based on demand.
I have launched the heat pump app using the CT feed (assuming it is in Watts), a cumulative of that feed, the inst energy feed from the HP heat meter and a cumulative of that as well as the ret and supply temperatures. However, I am now getting the following error:


Is there any way to fix it?

Thanks!
Rocio

Hello @Rolop I’ve made a couple of changes to the myheatpump app to hopefully make it a bit easier to debug this issue. Would you be able to run an update and post a new screenshot of the same error? The line number should be correct on this updated version and I should then be able to trace the issue. Thanks!

Hi @TrystanLea, I am not capable of updating emoncms.org (not sure if that’s what you meant) but here is an updated screenshot of the myheatpump app:
image

Thank you in advance!

Sorry @Rolop emoncms.org app module is now updated, could you try again?

Hi @TrystanLea this error appears now:
image

Thanks @Rolop could you try it again now, I’ve made another change.

Hi @TrystanLea , yesterday I had the app open for a long time and it didn’t give me any error.

Today, the first time I opened, an error showed up (sorry I couldn’t get a screenshot) but it hasn’t reappeared yet.
The first time I tried to create a myheatpump app i think i did something wrong and this error appeared:


Is there any way of eliminating this APP so it doesn’t appear on my list?

I have also made a post about incorporating the kWh period feature and histograms into my custom dashboards. I would really appreciate if you could check it out (Custom Dashboard: Adding histograms & kWh period feature).

Thanks a lot!

Thanks @Rolop I’ve made another update to this module that will hopefully fix the error shown in your last screenshot.

It is possible to delete the app with:

app/remove?name=My+Heatpump