Slope weather curve and questions

ninjaef

Just looked at 27th Nov Matt, it was 0C and  I used 17kw, I've got 98ish sq metres, no conservatory but loosing heat through 2.5m french doors which are old and need replacing. going to fix thermal curtains over tomorrow. that should help. 
I set temp to 20C from 6am to 9pm and 9pm to 6am it's 17C... not sure I could sleep in 18C but the octopus guy recommend it. phew 

ninjaef

matt_drummer said:

ninjaef said:

sorry Matt, thought you meant 500w  ..  ALL DAY ... you mean operation draw.  sorry. just had a look on my dashboard , 400w is max draw since 1pm. You're spot on again 😁

So, if you're warm enough then nothing is a million miles out.

Nothing much to worry about.

Only one other thing if you are running a weather dependent curve.

These Daikin heat pumps are not very happy below 30c flow temperature, particularly when it is warmer, so no real point setting your low point below 30c.

I was hoping to ensure max efficiency and getting educated too.



didn't know about the 30C .. mines set to x2= 25C at y2= 20C ambient. So that needs to go to 30? If so then won't that mess up the curve?
X1= 50 x2= -3 from the design spec they did for my home

matt_drummer

Similar to our house, I guessed it would be.

It sounds like it is working pretty much as it should.

I don't how cold it gets where you live but I am OK with 20kWh a day at 0c outside. If it was like that for a month it's 600kWh and I pay 7p per kWh for electricity. With battery losses, maybe 9p so about £50 for the worst month of heating, not bad really

18c is what MCS (the organisation that controls the grant) stipulate bedrooms need to be heated to, you can go lower if you want. Just avoid trvs if you can, your heat pump needs all the output it can get.

ninjaef

matt_drummer said:

Similar to our house, I guessed it would be.

It sounds like it is working pretty much as it should.

I don't how cold it gets where you live but I am OK with 20kWh a day at 0c outside. If it was like that for a month it's 600kWh and I pay 7p per kWh for electricity. With battery losses, maybe 9p so about £50 for the worst month of heating, not bad really

18c is what MCS (the organisation that controls the grant) stipulate bedrooms need to be heated to, you can go lower if you want. Just avoid trvs if you can, your heat pump needs all the output it can get.

my god who sells electric at 7p

Lytham in Lancashire. I'm with octopus , 2x 4hr  slots at 12p and one peak at 35p and rest is about 20p

7p 😮

what's with TRVs? all my rads have them   down and  some  turn up full .. to keep  the rooms equal warmth, about 20C ??

matt_drummer

I am with Octopus too.

It is an ev tariff. I have one but had no charger at home but got my wife an ev so needed a charger for her because I can't always take it to work to charge for free! They say they don't mind but I think it's taking advantage.

But it gets me electricity at 7p for 6 hours a day which is enough to charge my batteries, I have 38kWh of battery storage.

It's enough to run all day and more with no sun, I have a lot of panels too, and that is why I like to run my heat pump low but all day and night, it means I rarely draw more than my inverter can supply, you know, if we are cooking and heating it's a problem with a heat pump using loads of electricity.

trvs limit how much radiator capacity you have to get rid of the heat produced by the heat pump.

Not really a problem when it is cold but you will encounter a time where without enough radiators turned on (open and flowing water) you won't keep the heat pump running long.

It will short cycle and a Daikin will short cycle badly. They have a very aggressive start up procedure where for the first 20 minutes of a heating cycle is at full circulation pump speed. This results in a load of heat and if radiators are close the return temperature will rise so quickly that the cycle will last only a few minutes.

The heat pump will stop and then try again a few minutes late, but it doesn't start where it left off, it starts again from scratch with full heat output, and this will just continue.

It is one of the reasons they don't like low flow temperatures when it is warmer, the start is so aggressive that most houses won't have radiators big enough to deal with it.

I have huger, really huge radiators, so much that it is actually a problem. and I still cannot get it to run when it is warm at low flow temperatures, it produces so much heat it is impossible.

I do have a way to deal with it now by restricting the flow rate to the absolute minimum on start up but it also has other consequences.

Really, just be wary that whilst your trvs do no harm now they may well cause short cycling (very short cycling) when it is warmer and you still want heating, just keep an eye on it.

ninjaef

matt_drummer said:

I am with Octopus too.

It is an ev tariff. I have one but had no charger at home but got my wife an ev so needed a charger for her because I can't always take it to work to charge for free! They say they don't mind but I think it's taking advantage.

But it gets me electricity at 7p for 6 hours a day which is enough to charge my batteries, I have 38kWh of battery storage.

It's enough to run all day and more with no sun, I have a lot of panels too, and that is why I like to run my heat pump low but all day and night, it means I rarely draw more than my inverter can supply, you know, if we are cooking and heating it's a problem with a heat pump using loads of electricity.

trvs limit how much radiator capacity you have to get rid of the heat produced by the heat pump.

Not really a problem when it is cold but you will encounter a time where without enough radiators turned on (open and flowing water) you won't keep the heat pump running long.

It will short cycle and a Daikin will short cycle badly. They have a very aggressive start up procedure where for the first 20 minutes of a heating cycle is at full circulation pump speed. This results in a load of heat and if radiators are close the return temperature will rise so quickly that the cycle will last only a few minutes.

The heat pump will stop and then try again a few minutes late, but it doesn't start where it left off, it starts again from scratch with full heat output, and this will just continue.

It is one of the reasons they don look't like low flow temperatures when it is warmer, the start is so aggressive that most houses won't have radiators big enough to deal with it.

I have huger, really huge radiators, so much that it is actually a problem. and I still cannot get it to run when it is warm at low flow temperatures, it produces so much heat it is impossible.

I do have a way to deal with it now by restricting the flow rate to the absolute minimum on start up but it also has other consequences.

Really, just be wary that whilst your trvs do no harm now they may well cause short cycling (very short cycling) when it is warmer and you still want heating, just keep an eye on it.

wow, where do you learn all this. super.

ah ok EV and 38kw makes sense. I've no EV and 10kw battery , they will redirect you to be charging an EV every day hence 7p 😁

when ambient is around 16C the heating is off.

So now, should I open all the TRVs ?. they did replace all the rads of all different sizes .. for "equilibrium" they said.. whatever that meant. 

matt_drummer

ninjaef said:

matt_drummer said:

I am with Octopus too.

It is an ev tariff. I have one but had no charger at home but got my wife an ev so needed a charger for her because I can't always take it to work to charge for free! They say they don't mind but I think it's taking advantage.

But it gets me electricity at 7p for 6 hours a day which is enough to charge my batteries, I have 38kWh of battery storage.

It's enough to run all day and more with no sun, I have a lot of panels too, and that is why I like to run my heat pump low but all day and night, it means I rarely draw more than my inverter can supply, you know, if we are cooking and heating it's a problem with a heat pump using loads of electricity.

trvs limit how much radiator capacity you have to get rid of the heat produced by the heat pump.

Not really a problem when it is cold but you will encounter a time where without enough radiators turned on (open and flowing water) you won't keep the heat pump running long.

It will short cycle and a Daikin will short cycle badly. They have a very aggressive start up procedure where for the first 20 minutes of a heating cycle is at full circulation pump speed. This results in a load of heat and if radiators are close the return temperature will rise so quickly that the cycle will last only a few minutes.

The heat pump will stop and then try again a few minutes late, but it doesn't start where it left off, it starts again from scratch with full heat output, and this will just continue.

It is one of the reasons they don look't like low flow temperatures when it is warmer, the start is so aggressive that most houses won't have radiators big enough to deal with it.

I have huger, really huge radiators, so much that it is actually a problem. and I still cannot get it to run when it is warm at low flow temperatures, it produces so much heat it is impossible.

I do have a way to deal with it now by restricting the flow rate to the absolute minimum on start up but it also has other consequences.

Really, just be wary that whilst your trvs do no harm now they may well cause short cycling (very short cycling) when it is warmer and you still want heating, just keep an eye on it.

wow, where do you learn all this. super.

ah ok EV and 38kw makes sense. I've no EV and 10kw battery , they will redirect you to be charging an EV every day hence 7p 😁

when ambient is around 16C the heating is off.

So now, should I open all the TRVs ?. they did replace all the rads of all different sizes .. for "equilibrium" they said.. whatever that meant. 

Carry on with your trvs if you are happy, just be aware.

I am a sad middle aged competitive man and so i can't help myself getting my system as efficient as I can, I didn't intend to but it came from all my troubles with my first Daikin heat pump. I had a 9kW and it had to be replaced after a few months.

I get 7p every day whether I charge the car or not.

I replaced all my radiators myself after the first installation and they are sized so that I don't need trvs.

I don't have any and instead have good quality Danfoss lock shield valves that allow me to balance my radiators very well. They are sized to give 20c downstairs and 18c upstairs but it is often warmer, but I like it, my wife not so much.

ninjaef

matt_drummer said:

ninjaef said:

matt_drummer said:

I am with Octopus too.

It is an ev tariff. I have one but had no charger at home but got my wife an ev so needed a charger for her because I can't always take it to work to charge for free! They say they don't mind but I think it's taking advantage.

But it gets me electricity at 7p for 6 hours a day which is enough to charge my batteries, I have 38kWh of battery storage.

It's enough to run all day and more with no sun, I have a lot of panels too, and that is why I like to run my heat pump low but all day and night, it means I rarely draw more than my inverter can supply, you know, if we are cooking and heating it's a problem with a heat pump using loads of electricity.

trvs limit how much radiator capacity you have to get rid of the heat produced by the heat pump.

Not really a problem when it is cold but you will encounter a time where without enough radiators turned on (open and flowing water) you won't keep the heat pump running long.

It will short cycle and a Daikin will short cycle badly. They have a very aggressive start up procedure where for the first 20 minutes of a heating cycle is at full circulation pump speed. This results in a load of heat and if radiators are close the return temperature will rise so quickly that the cycle will last only a few minutes.

The heat pump will stop and then try again a few minutes late, but it doesn't start where it left off, it starts again from scratch with full heat output, and this will just continue.

It is one of the reasons they don look't like low flow temperatures when it is warmer, the start is so aggressive that most houses won't have radiators big enough to deal with it.

I have huger, really huge radiators, so much that it is actually a problem. and I still cannot get it to run when it is warm at low flow temperatures, it produces so much heat it is impossible.

I do have a way to deal with it now by restricting the flow rate to the absolute minimum on start up but it also has other consequences.

Really, just be wary that whilst your trvs do no harm now they may well cause short cycling (very short cycling) when it is warmer and you still want heating, just keep an eye on it.

wow, where do you learn all this. super.

ah ok EV and 38kw makes sense. I've no EV and 10kw battery , they will redirect you to be charging an EV every day hence 7p 😁

when ambient is around 16C the heating is off.

So now, should I open all the TRVs ?. they did replace all the rads of all different sizes .. for "equilibrium" they said.. whatever that meant. 

Carry on with your trvs if you are happy, just be aware.

I am a sad middle aged competitive man and so i can't help myself getting my system as efficient as I can, I didn't intend to but it came from all my troubles with my first Daikin heat pump. I had a 9kW and it had to be replaced after a few months.

I get 7p every day whether I charge the car or not.

I replaced all my radiators myself after the first installation and they are sized so that I don't need trvs.

I don't have any and instead have good quality Danfoss lock shield valves that allow me to balance my radiators very well. They are sized to give 20c downstairs and 18c upstairs but it is often warmer, but I like it, my wife not so much.

I'm an older mid aged man 😁 and also look to maximise income, minimise expense. We're all on the same coach. 
Ok, I'm good for now and learned so much from you. Thanks bud.

matt_drummer

No problem.

See how it goes and if you have more questions, then just ask.

Maybe also pop over to the open energy monito forum.

Lots of useful Daikin information plus lots of stuff from me and my Octopus/Daikin journey!

Latest Hardware/Heatpump topics - OpenEnergyMonitor Community

ninjaef

matt_drummer said:

No problem.

See how it goes and if you have more questions, then just ask.

Maybe also pop over to the open energy monito forum.

Lots of useful Daikin information plus lots of stuff from me and my Octopus/Daikin journey!

Latest Hardware/Heatpump topics - OpenEnergyMonitor Community

looks rather similar to my home assistant forum 👍