Integrate Predheat to use Open Energy Monitor sensors?

[zarch1972]

Is your feature request related to a problem? Please describe.

I already use Open Energy Monitor to monitor my heat pump with an electricity meter and heat meter.

https://emoncms.org/energystatsuk

Along with 100's of others at https://heatpumpmonitor.org/

I have all the sensors in play then pulled into Home Assistant using the emoncms integration

Electric in (instant and day) heat out (instant and day) Both of above split by DHW and heat only Outdoor temp Indoor temp Flow Temp Return Temp Flow Rate COP / Instant COP etc

Describe the solution you'd like

So rather than making calculations to predict forthcoming electricity (or heat) required, could Predheat use these actual figures? To give solid predictions based on recent fact?

Obviously, if you can't split your usage down into separate heating / DHW usage numbers, then some accommodation for that would be required.

Note: not everyone using Open Energy Monitor has separate heating and hot water values as it can require and extra bit of kit to monitor the 3 way valve (whether it's doing heating or hot water)

But I think it makes sense to move forward with separate heating / hot water totals, otherwise calculations are going to get skewed by the hot water requirement if coming out of a single kWh 'heat' figure?

I would be happy to help with any trials / implementation

Cheers, Mick

Describe alternatives you've considered A clear and concise description of any alternative solutions or features you've considered.

Additional context Add any other context or screenshots about the feature request here.

[johnwb87]

+1 on this. I’m expecting to have OEM on a heat pump by the end of the year and want to use all the data to drive predheat.

[johnwb87]

@zarch1972 Did you make any progress with this? Obviously not changing how PredHeat works but in plumbing in some of the sensor to the configuration.

[johnwb87]

@springfall2008, @gcoan could you please tag this issue as an Enhancement. Thanks.

[zarch1972]

In the predheat config I've put in the internal room and outside temps as well as internal target temp from the Vaillant heat pump controller.

I also put the heat output from the heat pump into the 'heating_energy' put flow temp in and and some other stuff.

But cos there's no heat at the moment I have no idea what predheat is doing. And because I've only just starting setting up in the summer I have no reference to what it can do in the winter.

Also, because i'm doing two hot water runs a day and the flow temp / heat output is used in those two, who knows. Hence it would be useful to have a heating / hot water binary sensor perhaps?

I think predheat using heat pump actuals from open energy mon needs some thought. :-)

[zarch1972]

Heating came on for the first time this morning. 8C outdoors and dining room finally dropped below 20C.

Was a good reminder that I need to understand Predheat more and look at how much kWh is predicted per day... and whether that gets passed over to predbat forecast/plan/requirements?

Is there a way to get a new column in "Plan" to see planned/forecasted heat load kWh or something?

[johnwb87]

Hi,

My heat pump and OEM should be up running by next month.

I’ll be able to get involved in seeing how this works then and hopefully making some targeted suggestions for improvements.

[zarch1972]

Is there a Pred Heat sensor somewhere that shows the forecasted heating (and hot water) electricity for the day? I'd like to compare that to what my heat pump is actually using.

I had the situation yesterday where Predbat exported in the afternoon, but i'd run out of battery capacity by the evening because of what the heat pump needed through the day. So i'm not sure how much kWh (for the heat pump) is being added to the house prediction?

Hope that makes sense?

[zarch1972]

ignore me, I found predheat.heat_energy$external, which i'd not added in as a load_forecast. RTFM. Although this is probably 'heat only', so I need to find a way to add daily hot water usage onto the total.

[johnwb87]

Yes, I think it is predheat.heat_energy. I think the hot water can be predicted fairly well by predbat with the one assumption being that your scheduling is consistent. For example when I have been using immersion heater overnight because it is a consistent schedule predbat sees that in the historic data and so it can forecast it.

Do you have any of the Predheat charts set up?

My own OEM set up is just days away now so I will be actively playing with this myself very soon.

[zarch1972]

I need to do some digging around graphs and get my head around all this now i've found this predheat.heat_energy

Our hot water usage through the heat pump is quite consistent through the year, so I could easily just add 5kWh electricity each day (although half of that usually overnight in the off peak period).

This also piqued my interest: https://github.com/springfall2008/batpred/discussions/837

[johnwb87]

I need to do some digging around graphs and get my head around all this now i've found this predheat.heat_energy

Our hot water usage through the heat pump is quite consistent through the year, so I could easily just add 5kWh electricity each day (although half of that usually overnight in the off peak period).

This also piqued my interest: #837

Yes, OK I agree something to think about and look into. I was hoping to work with @springfall2008 once my system is up and running to, as a minimum, improve the documentation. For example all heat pump installs should have a very good heat loss calculation, so how can we use that.

[zarch1972]

Sounds good and i'd be happy to help.

I'm sure by using the method @BuhJuhWuh has created, we could come up with a simple heat only usage graph based on MCS design details; Design Outside Temp, Heat Loss kW, Target Flow Temp and Design Inside Temp.

I'm all for nailing things exactly using lots of data, but most people probably won't have a way of getting all those inputs (like in Predbat now), so a simple ball park figure could work nicely for most people.

Then you can just add on water demand as a separate amount per day, as that is usually pretty static in the bigger picture.

I have 3 years of open energy mon data and have analysed my system in lots of articles. https://energy-stats.uk/third-winter-with-our-vaillant-heat-pump/

So hopefully I can bring some experience and numbers to the party.

[johnwb87]

@zarch1972 oh wow they’re your articles, I’ve read many of them already! I will have a 5kW Vaillant and am planning on implementing “sweet spot” mode for heating a 250l tank.

[zarch1972]

Infamy! Infamy! They've all got it in for me! LOL

Email me via the site if you want any help, i'd be happy to go through stuff I've learnt.

I'm currently writing an article about 'how much electricity does a heat pump use', which is very much tied to what we are talking about here. So many variables!!!!

[BuhJuhWuh]

Happy to chip in in due course. At the very least I'll have to go and remind myself what I actually did and document that a bit better!

Edit: the stuff I noted here is the basis of it, but not the whole story - had to do some additional later to avoid double counting.

[zarch1972]

This is the latest article I wrote about this sort of subject https://energy-stats.uk/how-much-electricity-does-a-heat-pump-use/

Does a lot of HTC calcs. Hoping I can talk this further an come up with a generic HTC graph based on the things we've been talking about.