The graphs you see in the Analysis section of the app use estimated data based on a number of different data points:
- Your internal temperatures
- The provided heat pump size
- Your tariff information
- The heat pump's compressor speed*
Most heat pumps do not have internal power metering, so this allows us to let you know how much electricity you're using without any additional hardware costs.
If you think your graphs are wrong, there are a few steps you can take.
- Compare your graphs to your energy bills. During the winter, heat pumps usually account for the majority of an electricity bill, unless you have other high-energy devices such as EV chargers in your home. If the values on the graph are equal to a bit over half your bill, then they are probably reasonable accurate.
- Update your heat pump size. Your heat pump size is given by the installer when the Passiv Smart Thermostat is commissioned. This isn't guaranteed to be correct. To see how to update this, check How can I update my heat pump size?
- Update your tariff. If your tariff is wrong, then the Analysis graphs will be reporting incorrect costs for your electricity. If you have ecoHeat on, this also could mean that your heat pump isn't making the most of cheap electricity rates. To see how to update this, check How do I change my tariff?
* To explain the technical talk, your heat pump's compressor is what determines how hot the water running through your radiators is. We can determine what percentage of maximum power the compressor is running at. By combining this information with your heat pump size, we can determine how much electricity the heat pump is using!