Energy efficiency monitoring

[MalteSchm]

Regulations in Germany require energy efficiency monitoring to get heat pump government founding. The German distributor of MHI devices has a solution that fulfills this requirement. This solution connects to the SPI port (*) of all IU to accomplish this. Looking at the solution this seems to work on the data that is also used by MHI-AC-Ctrl. I'm trying to understand if this can be realized with MHI-AC-Ctrl. Initially I thought that the

1. Room temperature
2. Temperatur of the returned (heated or cooled) air
3. Volumetric air flow, calculated via fan speed lookup

could be used to calculate the energy transferred by a single IU. This could be used together with an energy meter to measure efficiency. Having build and installed an MHI-AC-Ctrl I believe that 2) (Temp of returned air) is not available. Is this understanding correct? Are there maybe also other ideas to accomplish this?

(*) My understanding from reading the manual is that they convert the data to the X/Y bus to bring it into a device that sends this to the cloud. Energy efficiency monitoring is then provided by this cloud service.

[glsf91]

Returned air should be available as OpData/RETURN-AIR

[MalteSchm]

Is room temp then also returned? I saw Troom and RETURNED-AIR but both values were almost the same

[glsf91]

yes, that is Troom. indeed they are almost the same. don't know why.

[MalteSchm]

Troom and RETURN-AIR are both driven by the same temperature sensor that sits here:

I did a quick fan / heat test and both values changed. I don't think this is it. The sensor measures room temperature

[glsf91]

We can not do better then this. This is available through opdata: doc

It is also a matter of definitions. Is room temperature the temp somewhere in the room (so not measured in the AC) or the temp air entering the AC (measured with above sensor)? Is "Temperatur of the returned" the temp of the air which is leaving the AC or the air temperature returned to the AC (measured with above sensor)?

Do you have a link to the device and manual ?

[MalteSchm]

We can not do better then this. This is available through opdata: doc

Understood. I also like to say that I'm not asking for a new feature. I can implement this myself if I'd only knew the approach

Do you have a link to the device and manual ?

You mean the indoor unit? That is a SRK-15ZS-WF

More insights: The temperature sensor with the orange cables is THI-R3. The cables are visible in the background in the picture above. The other temperature sensor is THI-R1

[glsf91]

There is no more available then the opdata. So you or we cannot add more.

No, a link to the device and manual of the german distributor.

[MalteSchm]

I'm using Outdoor unit: SCM41ZS-W Indoor units: SRK-15ZS-WF

The required components that enable energy efficiency monitoring are: BIKN2-E - This converts the SPI bus interface into an bus called "X/Y bus" Comptrol-Web - Connects to the X/Y bus and the internet to provide data to the cloud e-Comptrol - Is the cloud, with a webinterface that provides energy efficiency graphs In addition an energy meter may be needed. I saw a note in one manual a while ago.

I liked the diagram on page 6-12 in the doc shown on this page: https://www.fachklima24.de/mitsubishi-heavy-ct4web-e-comptrol-4web-steuerung-und-ueberwachung.html?language=de

Overview: https://www.s-klima.de/beg-foerderung/ Details: https://www.s-klima.de/beg-foerderung/auswahl-waermepumpen/

This effort is insane in my mind. It is very likely driven by the subsidy. This setup allows selling an overpriced extension to re-direct some of the money. It annoys me that this should be needed. At the same time only data source is the SPI bus. The Wifi module should have all the data and is internet connected and I feel that I'd be ripped off by purchasing these items.

[absalom-muc]

@MalteSchm : Are you aware that there is some additional HW docu related to Operation Data here? I can't imagine that for BAFA/KFW a self-made solution for energy monitoring is acceptable since it is not protected against manipulation.

[MalteSchm]

Yes I am aware of this document. I also checked some MHI pipeing diagrams. They are clear regarding the different temperature measuring points. They also use the same names. While looking at older pipeing diagrams it became clear to me that MHI has changed the system configuration over time. This explains why some measurements do not provide useful info.

Right now I believe the the EEV pulse rate is used to derive the coolant flow. This flow rate carries a certain latent energy. The sum of the energies of all indoor units divided by the used energy of the outdoor unit is the efficiency

If I'd only knew how EEV pulse rate converts into coolant flow...

I'm not concerned with BAFA security requirements. There is no such statement in the requirements and since I don't report these numbers there is no point in me cheating. But getting them to accept such a solution will not be easy

[glsf91]

I cannot add more to this I think. I expect all data which is used in that external device should also be available in mhi-ac-ctrl. You have to figure out what to use.

[glsf91]

I think we can close this one. Otherwise let me know