Another 'Cool Energy' heatpumps thread

[alfaTom]

On 09/11/2025 at 15:41, MikeSharp01 said:

Is that the wiring center? I chose not to have that assuming there was a screen on the unit somewhere and I would be controlling via the BMS anyway - perhaps it would be useful to have anyway.

 

Yes it is, at least the one used on the newer ET models.

They need to sort a few QoL bits out, the WiFi pairing via the app was a mess, and they have a temp sensor pocket on the buffer and the DHW cylinder, but it only supports the DHW temp sensor in the wiring centre.

 

I have Cool Energy coming out shortly to do the final commissioning so I'll try get a bit of info from them then. I'd love to try work out the COP of the unit but all the center gives me is the compressor Amps which isn't enough

[JohnMo]

30 minutes ago, alfaTom said:

buffer

Why and if cool energy say so, why again? They just aren't needed

[HughF]

4 hours ago, JohnMo said:

Why and if cool energy say so, why again? They just aren't needed

Standard SPRSUN design choice - commonly used in China where electricity is cheap and they’re competing against direct electric heat so any cop is a good cop.

 

I see it in 75% of the Vaillant schematics too, which isn’t very good

 

I just taped my buffer probe to the 22mm that feeds the rads and covered it in insulation.

[Jack_H]

The buffer probe on the ET-10 has been connected to the return pipe just before the heat exchanger - I was told this was to measure and regulate the delta t setpoint, which makes sense.

 

 

[JohnMo]

25 minutes ago, HughF said:

Standard SPRSUN design choice

So just straight badge engineering?

 

And selling product, sell heat pump and tell the purchaser You Need a Buffer, because some added it to a drawing and we can't be arsed to change it.  Great

[HughF]

9 hours ago, JohnMo said:

So just straight badge engineering?

 

And selling product, sell heat pump and tell the purchaser You Need a Buffer, because some added it to a drawing and we can't be arsed to change it.  Great

Pretty much, yep….

 

the new grant r290 hydraulic schematic appears to be properly designed (no buffer, no trv heads, single zone)… most of the others I’ve seen are just standard buffer + secondary pump. Especially Chinese ones.

[HughF]

9 hours ago, Jack_H said:

The buffer probe on the ET-10 has been connected to the return pipe just before the heat exchanger - I was told this was to measure and regulate the delta t setpoint, which makes sense.

 

 

That’s a good place for it. A lot of other manufacturers already have flow temperature sensors installed internally so even when you do run them with a buffer/llh/plate/whatever you don’t need for an extra temp sensor. SPRSUN doesn’t have an internal sensor so the buffer probe needs to go somewhere.

[MikeSharp01]

14 hours ago, alfaTom said:

I'd love to try work out the COP of the unit but all the center gives me is the compressor Amps which isn't enough

I think the attached spreadsheet document, from Cool Energy, might help but have not looked carefully. Its the BMS Modbus link.(Unit Information and AI tabs).

 

R290 heat pump X1.HL092H.K05.001-1.MODBUS_RTU.V100A07 - 2025-4-16.xlsx

[Bramco]

4 hours ago, MikeSharp01 said:

I think the attached spreadsheet document, from Cool Energy, might help but have not looked carefully. Its the BMS Modbus link.(Unit Information and AI tabs).

 

R290 heat pump X1.HL092H.K05.001-1.MODBUS_RTU.V100A07 - 2025-4-16.xlsx 41.66 kB · 4 downloads

 

Interesting spreadsheet but I think you need the flow and temperature to work out the kW generated against the mains current and voltage as the input.

There are kits to do this -> https://docs.openenergymonitor.org/applications/heatpump.html

They also have a public website where you can publish your data - useful to see the CoPs being achieved in the real world.

https://heatpumpmonitor.org/

 

 

[JohnMo]

9 minutes ago, Bramco said:

They also have a public website where you can publish your data - useful to see the CoPs being achieved in the real world.

https://heatpumpmonitor.org/

Some really impressive CoP and SCoP numbers, but you really have to check them over, some on there only record some electric data, and miss internal units out, which is needed to actually calculate the CoP. Seen a few where the unit runs great and good CoP while running, but electric input stops with compressor cycle stopping, but the unit is still pump 10L/min, running the controller all at 1W input. Also while doing so recording a cop of of about 10.

 

Other are getting a genuine SCoP of 5+. By using well sized units, tuned well and that modulate well and have super long run times.

 

17 minutes ago, Bramco said:

There are kits to do this -> https://docs.openenergymonitor.org/applications/heatpump.html

I have one it's great to actually compare what you think, and what real happens. You will be surprised how much standby time can kill real day to day CoP.

[JohnMo]

20 hours ago, alfaTom said:

I'd love to try work out the COP of the unit but all the center gives me is the compressor Amps which isn't enough

To get full instantaneous CoP you need

 

dT, flow rate to get the work done. If you have a buffer you will need to take account of buffer distortion across buffer, when doing the calculation. You also need all the electric inputs, on the heat pump, any external circulation pumps both secondary and primary if you have them and power input to controller(s) to work out Watts of electricity used.

 

All this needs to be accurate, rounded numbers are good enough. Just looked at the feeds and it's one decimal place on temperature and electricity and two places for flow rate.

 

 

[MikeSharp01]

7 hours ago, Bramco said:

There are kits to do this -> https://docs.openenergymonitor.org/applications/heatpump.html

Yes got to order one of these Level 3 kits but so many options - will need a phone call to them I think.

 

[JohnMo]

4 minutes ago, MikeSharp01 said:

Yes got to order one of these Level 3 kits but so many options - will need a phone call to them I think.

 

That's what I did in the end, very helpful