It’s been on my list for a while to implement a way to flag and hide systems with monitoring errors on HeatpumpMonitor. Some have raised concerns about data quality seeing systems listed with issues such as heat output when the compressor is off due to temperature sensor offset errors or defrost energy not being taken into account. It’s clearly important that the data on HeatpumpMonitor can be relied upon to accurately reflect the real system performance.
This hasnt been that much of an issue yet as all of the systems listed in the top spots do not have these issues but it would become more of an issue if a system with significant measurement errors did occupy a top spot and so it’s good to get ahead of this issue. It can be more of an issue when making comparisons on particular brands e.g Daikin where there are more systems using heatpump integration as the data source.
At the same time we do not want to discourage contributions that use heat pump integration and even systems with measurement errors still provide useful data on a whole range of system attributes such as system control/cycling/modulation.
Those of us with experience in looking through the data can identify common measurement issues and can take this into account when comparing systems but it’s less straightforward for newcomers to the site.
I noted that we wanted to look at this issue in the recent HeatpumpMonitor.org next steps post:
and have since implemented a first pass at this feature, systems with flagged metering errors are now hidden but can be enabled from the ‘show systems with’ box:
Selecting only the systems flagged with metering errors, we can see a little yellow exclamation mark, hover over the mark to see a note about what errors were identified.
it’s also possible to select the node field and show it in the table for quick reference:
Not including defrost energy does not have that much of an effect on long term COP figures, it usually results in a 0.1 COP difference e.g it might list 4.1 rather than 4.0.
Temperature sensor offset error is more significant. Here’s a good example, the small DT error here is resulting in a suggested heat output of 385W when the compressor has clearly been off for some time.
The COP in window of 4.79 drops to 4.43 without this heat contribution:
I’m not 100% sure that I’ve got this feature quite right yet. Should we flag systems that do not include defrost energy differently to those with temperature sensor offset errors perhaps? Perhaps a yellow flag for defrosts and orange for temperature sensor offset errors? Is it fair to hide systems on the main list which do not include defrosts or is a flag icon fine?
