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PWM pump or not?

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(@bontwoody)
Noble Member Contributor
2911 kWhs
Joined: 2 years ago
Posts: 415
Topic starter  

@iancalderbank This pump would do the job wouldnt it Ian? Thanks Mark

https://www.ebay.co.uk/itm/234982440002?var=0&mkevt=1&mkcid=1&mkrid=710-53481-19255-0&campid=5338942597&customid=Cj0KCQjwi46iBhDyARIsAE3nVrax00NlnUcshtoguRnLJTpoB3zshlUaja4e4tRY7fztwnUHfhE5p80aAu-YEALw_wcB&toolid=20006&

House-2 bed partial stone bungalow, 5kW Samsung Gen 6 ASHP (Self install)
6.9 kWp of PV
5kWh DC coupled battery
Blog: https://thegreeningofrosecottage.weebly.com/
Heatpump Stats: http://heatpumpmonitor.org/system/view?id=60


   
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(@iancalderbank)
Noble Member Contributor
3640 kWhs
Joined: 2 years ago
Posts: 644
 

@bontwoody pretty sure it will yes. This doc is your bible (page 23)

@derek-m I'm actually trying to setup public visibility of my stats via emoncms / heatpumpmonitor.org at the moment, but here's some individual snips of the same time window , hope these are easier to read.

image
image
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image

my system performance is not great yet - COP is only ~3 - but  I haven't balanced yet, I know I have a shortcut radiator lurking as DT is too low.

My octopus signup link https://share.octopus.energy/ebony-deer-230
210m2 house, Samsung 16kw Gen6 ASHP Self installed: Single circulation loop , PWM modulating pump.
My public ASHP stats: https://heatpumpmonitor.org/system/view?id=45
11.9kWp of PV
41kWh of Battery storage (3x Powerwall 2)
2x BEVs


   
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(@bontwoody)
Noble Member Contributor
2911 kWhs
Joined: 2 years ago
Posts: 415
Topic starter  

@iancalderbank Thanks Ian, I was looking at page 12 and was pretty sure but wanted some confirmation 🙂 Ive just managed to get some data for my heatpump out of EmonPi, but the heat meter is underreporting the flow rate so Ive had to put in a correction factor based on the stated flow from the Samsung controller. looking pretty reasonable at the moment

HPMon

House-2 bed partial stone bungalow, 5kW Samsung Gen 6 ASHP (Self install)
6.9 kWp of PV
5kWh DC coupled battery
Blog: https://thegreeningofrosecottage.weebly.com/
Heatpump Stats: http://heatpumpmonitor.org/system/view?id=60


   
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(@bontwoody)
Noble Member Contributor
2911 kWhs
Joined: 2 years ago
Posts: 415
Topic starter  

@iancalderbank Fitted the new PWM pump Ian, all working well and it has reduced the power input by 30 W by reducing the flow rate down to 9 lt/min from about 15lt/min. I was a little surprised at that as I thought 15 was supposed to be optimal but i guess it knows what its doing 😀 delta T is still about 3 degrees C though which may or may not be important.

House-2 bed partial stone bungalow, 5kW Samsung Gen 6 ASHP (Self install)
6.9 kWp of PV
5kWh DC coupled battery
Blog: https://thegreeningofrosecottage.weebly.com/
Heatpump Stats: http://heatpumpmonitor.org/system/view?id=60


   
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(@iancalderbank)
Noble Member Contributor
3640 kWhs
Joined: 2 years ago
Posts: 644
 

@bontwoody my experience has been that (in low load situation) it reduces the flow rate to just a smidgen above the min flow rate acceptable to the heat pump - 12l/min in my case with the 16kw unit.  this is about a 3.5kw heat output at DT4.  to get DT5 it'd have to drop the flow rate below the min that is acceptable to the heat pump which I assume is the reason it doesn't do that.

good to hear it works anyway!

My octopus signup link https://share.octopus.energy/ebony-deer-230
210m2 house, Samsung 16kw Gen6 ASHP Self installed: Single circulation loop , PWM modulating pump.
My public ASHP stats: https://heatpumpmonitor.org/system/view?id=45
11.9kWp of PV
41kWh of Battery storage (3x Powerwall 2)
2x BEVs


   
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(@bontwoody)
Noble Member Contributor
2911 kWhs
Joined: 2 years ago
Posts: 415
Topic starter  

@iancalderbank That makes perfect sense Ian. Im just having my Mixergy cylinder fitted today so i can hook it up to my Eddi. While that happens Im exploring Home assistant. It was a bit fiddly to get the right version installed but Ive managed that now and an delighted to find that it can connect to both of the above. Ive already got it hooked up to my openenergy monitor system and it looks possible to include Solar Fusion as well!

House-2 bed partial stone bungalow, 5kW Samsung Gen 6 ASHP (Self install)
6.9 kWp of PV
5kWh DC coupled battery
Blog: https://thegreeningofrosecottage.weebly.com/
Heatpump Stats: http://heatpumpmonitor.org/system/view?id=60


   
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(@bontwoody)
Noble Member Contributor
2911 kWhs
Joined: 2 years ago
Posts: 415
Topic starter  

@iancalderbank Strange thing happened last night, came home about 10pm so no heating on and noticed the pump turned itself on for about 5 mins at high power. Any idea why?

image

House-2 bed partial stone bungalow, 5kW Samsung Gen 6 ASHP (Self install)
6.9 kWp of PV
5kWh DC coupled battery
Blog: https://thegreeningofrosecottage.weebly.com/
Heatpump Stats: http://heatpumpmonitor.org/system/view?id=60


   
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(@iancalderbank)
Noble Member Contributor
3640 kWhs
Joined: 2 years ago
Posts: 644
 

@bontwoody I think you have other monitoring, temperatures, energy etc - what did those say?

was it below or close to 3C where you live?

there is a "frost protection" in the samsung, if the outside temp is <3C and there's been no pump run for at least an hour, it will run the pump for 5 mins (at full speed by default). if you have DHW it'll open the DHW valve as well. which takes heat from your DHW and uses it to "warm the heat pump up".

My octopus signup link https://share.octopus.energy/ebony-deer-230
210m2 house, Samsung 16kw Gen6 ASHP Self installed: Single circulation loop , PWM modulating pump.
My public ASHP stats: https://heatpumpmonitor.org/system/view?id=45
11.9kWp of PV
41kWh of Battery storage (3x Powerwall 2)
2x BEVs


   
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(@bontwoody)
Noble Member Contributor
2911 kWhs
Joined: 2 years ago
Posts: 415
Topic starter  

@iancalderbank That sounds like exactly what it did but the outside temperature was 14C. I will keep an eye on it. Not a massive issue but curious

 

image

House-2 bed partial stone bungalow, 5kW Samsung Gen 6 ASHP (Self install)
6.9 kWp of PV
5kWh DC coupled battery
Blog: https://thegreeningofrosecottage.weebly.com/
Heatpump Stats: http://heatpumpmonitor.org/system/view?id=60


   
ReplyQuote
(@iancalderbank)
Noble Member Contributor
3640 kWhs
Joined: 2 years ago
Posts: 644
 

@bontwoody I've been noticing mine now runs for 5 mins every 24hrs. it has nothing else to cause it to run so I guess this is a "stop the pump sticking" thing.

My octopus signup link https://share.octopus.energy/ebony-deer-230
210m2 house, Samsung 16kw Gen6 ASHP Self installed: Single circulation loop , PWM modulating pump.
My public ASHP stats: https://heatpumpmonitor.org/system/view?id=45
11.9kWp of PV
41kWh of Battery storage (3x Powerwall 2)
2x BEVs


   
ReplyQuote
(@bontwoody)
Noble Member Contributor
2911 kWhs
Joined: 2 years ago
Posts: 415
Topic starter  

@iancalderbank Well its good to know its not unusual behaviour 🙂 Mixergy and Eddi all working now, paying standing charges only now for a week or two. Have appointment from Octopus to cap off my gas too. Im exporting loads in this nice weather so am trying to get and export meter fitted.

House-2 bed partial stone bungalow, 5kW Samsung Gen 6 ASHP (Self install)
6.9 kWp of PV
5kWh DC coupled battery
Blog: https://thegreeningofrosecottage.weebly.com/
Heatpump Stats: http://heatpumpmonitor.org/system/view?id=60


   
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(@fazel)
Reputable Member Member
1085 kWhs
Joined: 1 year ago
Posts: 124
 

Posted by: @iancalderbank

@bontwoody I've been noticing mine now runs for 5 mins every 24hrs. it has nothing else to cause it to run so I guess this is a "stop the pump sticking" thing.

Glyn's 5kW Samsung does the same, runs the pump for a few minutes. You would prob be able to check the display on the pcb whilst it's happening

image

@iancalderbank if you are not using the HP for longer periods, not turning everything off as it takes 100w on standby...?

Do you have it covered/masked or does it have anything in front of it?

 

 


   
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