Introduction to heat pump monitoring hardware

[@stuartpagelane9823]

hey john its super to see you are still alive ha

[@johntisbury]

Thank you for this John, this is the only sensible explanation of the hardware needed for OpenEnergyMonitoring that I have come across.

[@steveme120]

a really excellent set of talks really appreciated you taking the time to do this please keep them coming

[@philipbroggio9315]

I have been using Home Assistant to get something similar. I have temp probes on flow and return and the thermometer is a wifi system linked to Tuya which can display in HA. Similarly I have three Govee thermometers around the house in Study, Living Room and a bedroom. For external temperatures I have used three hourly Met office integration. I have an PV, EV and Zappi and have four CT clamps linked to the myEnergi system. The heat pump is on its own spur and fusebox so have a CT clamp with a Harvi. I can display the energy use using the myEnergi integration in HA. The bit that is missing is the flowrate !!!! My HA is set up on a Rpi 4 and working well . Any suggestions what flow monitor I could use to link it into Home Assistant ? I could then calculate heat by creating a virtual sensor combining the Delta T from flow and return and the measured flowrate to get KW. At the moment I can only get daily redings from the Daikin controller which has all the info in it but there is no way of gathering real time data !!! Still good news is my COP since last June is sitting at 3.52 for Heat and 2.3 for DHW 🙂

[@johncantor4056]

Sounds good. For flow sensor, how about using a Sika or Grundfoss VFS sensor. Some ASHPs use them (Ecodan use Sika), they are also in boilers. Not as good as a proper heat meter, but could be good enough. Some give a voltage output proportional to flow-rate, and maybe you could input the voltage in some way to your system. The 40lit/min ones are quite restrictive. 100lit/min are less accurate, but lower pressure drop.

[@richardc1983]

This is a great channel. I have an air to air system and would like to monitor my system that has 5 indoor units and 1 outdoor compressor unit. What can I use for this?

[@johncantor4056]

Mmm.. its a little hard to properly monitor such a thing. I dont know of a way of knowing the heat ouput to air. Its useful to measure the power, and a CT clamp to measure current (assuming 1kw = 4 amps) should be good enough. What do you want to learn? It would be interesting to have room sensors (emonTH, with a probe sensing the warm air coming from the unit... I would find it interesting, but not sure what you would learn from it. cheaper options might be to buy some wifi thermometers and display it on an app. I guess you has fan-speed options?? if so, fastest air is probably most energy-efficienct, but noisy and possibly drafty. maybe you can help to compare input power with different air flows. possible my 'Carnot COP estimator might help you guess the COP

[@manoo422]

3:17 How do you estimate flow rate from 2 temperatures...?! 7:26 "Kettle tower meter" ???! 12:03 The ONLY way to know how efficient you heat pump is requires an inline 'heat meter'. What the heat pump unit displays are usually complete fantasy.

[@johncantor4056]

Yes, the only way to know the heat output is with a proper heat meter, but this is a very considerable extra expense. But, i am often helping people get the best output from what HP they have, and whilst knowing heat (kw) is ideal, its hard to achieve. If pump is fixed-speed (non inverter), you sometimes can conclude (not always) that the flow-rate is about constant, so you can glean quite a bit from dt. Mostly, i'm finding that some of the expensive-to-run systems simply produce water at a temperature that is considerably hotter than the radiators are getting. Also, the cycling can cause the flow temperature to stray well above what it might for a system spending more time at steady-state. So, there can be a considerably benefit using a simple non-intrusive temperatures and input monitor. But I agree, heat meter would be better.