Octopus Heat Pumps

matt_drummer

I should add something.

Modulation may work better at controlling the Madoka in houses other than mine.

My radiators are really too big, even at the the lowest flow temperatures they over power the Madoka's room temperature control.

If you have more modestly sized radiators the modulation (load compensation) should work better.

Set it at 5c and see what happens.

It won't give the best efficiency as the heat pump will be moving in and out of the best flow temperature but it should back the heat pump off so it takes linger to get to the set room temperature although you still have to wait for the house to cool by 2c before you get heat again.

You will have to play with all your settings to find something that works.

Without any monitoring this will be more of a challenge unless you are not too worried about efficiency.

oliver1951

matt_drummer said:

Spies said:

What's the overshoot value set to under Space heating on the MMI?

Overshoot is normally adjustable between 1c and 4c, but may not be depending on the heat pump, the heating mode chosen and the firmware installed on the heat pump.

My 8kW required a firmware update to make the adjustment possible in radiator mode, it was locked at 1c before the update.

Overshoot sets the amount the heat pump can exceed the requested flow temperature, either a fixed flow temperature or that determined by the weather dependent curve.

There is also modulation which is only adjustable once activated and only in use if using the Madoka to control room temperature. It is adjustable between 1c and 10c and is what is known as load compensation.

Neither of these setting will change what is going on with @oliver1951

What you are seeing is the hysteresis on the room temperature control. It is 2c and not adjustable.

If the room temperature is set at 20c then the heat pump will turn off at 20.5c and come back on at 18.5c.

I don't like it and it is one reason I don't use it.

You can make it take longer to get to the required room temperature by reducing heat output but once the required temperature +0.5c) has been reached the house has to cool by 2c before the heat pump will come on again.

It's uncomfortable for me and I wanted a constant heat.

I also found it inefficient in terms of COP.

The heat pump runs less but when it is running it uses more electricity at a lower COP.

So, if you want 20c, set it to 21c, it will heat to 21.5c and come on again at 19.5c

With regard to user profile, you can adjust very little as an advanced user (code 1234). You need to go into installer settings (code 5678) to make any real changes.

Hi Matt. I have the 8kw Daikin, same as yours. I have my temp set for 16c. The other day it was cutting in at about 15.9 and out and 16 and back in on 15.9. So no 2 degree drop. I’m going to have another try to get into the MMI and look at the settings. I have a hive controller, which doesn’t do a lot at all. When I spoke to hive, believe it or not, they couldn’t tell me what the drop back temp was , nor if it could be adjusted. Matt I can’t remember did you get your monitoring equipment installed by octopus or did you get it retrofitted? 

Reed_Richards

matt_drummer said:

There is also modulation which is only adjustable once activated and only in use if using the Madoka to control room temperature. It is adjustable between 1c and 10c and is what is known as load compensation.

"Load Compensation" for gas boilers is the ability to automatically increase the boiler output when there is a large difference between the actual room temperature and the set room temperature and decrease the output when the two temperatures are close.  It's a useful feature and should minimise cycling.  Any gas boiler and controller combination that conforms to the Opentherm standard should be able to do Load Compensation.

Heat pumps have no Opentherm equivalent so for Load Compensation (assuming the term is used to mean the same thing) you need the manufacturer's own controller mounted somewhere appropriate like a living room.  With such a finely-tuned system as @matt_drummer has achieved, it's probably a redundant feature but it could be useful when you are still getting used to running a heat pump.    

FreeBear

Reed_Richards said:

matt_drummer said:

There is also modulation which is only adjustable once activated and only in use if using the Madoka to control room temperature. It is adjustable between 1c and 10c and is what is known as load compensation.

"Load Compensation" for gas boilers is the ability to automatically increase the boiler output when there is a large difference between the actual room temperature and the set room temperature and decrease the output when the two temperatures are close.  It's a useful feature and should minimise cycling.  Any gas boiler and controller combination that conforms to the Opentherm standard should be able to do Load Compensation.

Heat pumps have no Opentherm equivalent so for Load Compensation (assuming the term is used to mean the same thing) you need the manufacturer's own controller mounted somewhere appropriate like a living room.  With such a finely-tuned system as @matt_drummer has achieved, it's probably a redundant feature but it could be useful when you are still getting used to running a heat pump.    

The OpenTherm specification has a section specifically aimed at heat pumps (both for cooling and heating). MBus can also be found on some systems, and I see Daikin offer a ModBus interface for their Altherma range (at a price). Don't see load compensation as an option in OT, MBus, or ModBus interfaces. In fact, such functionality is probably best left to the thermostat where you can apply PID gains and call for lower a lower flow temperature as the set point is approached.

I use a PID control for heating to reduce flow temperature, and leave the boiler to handle modulation.

matt_drummer

Reed_Richards said:

matt_drummer said:

There is also modulation which is only adjustable once activated and only in use if using the Madoka to control room temperature. It is adjustable between 1c and 10c and is what is known as load compensation.

"Load Compensation" for gas boilers is the ability to automatically increase the boiler output when there is a large difference between the actual room temperature and the set room temperature and decrease the output when the two temperatures are close.  It's a useful feature and should minimise cycling.  Any gas boiler and controller combination that conforms to the Opentherm standard should be able to do Load Compensation.

Heat pumps have no Opentherm equivalent so for Load Compensation (assuming the term is used to mean the same thing) you need the manufacturer's own controller mounted somewhere appropriate like a living room.  With such a finely-tuned system as @matt_drummer has achieved, it's probably a redundant feature but it could be useful when you are still getting used to running a heat pump.    

This is exactly what the Madoka and MMI do and the load compensation effectiveness is adjustable to suit the characteristics of the house. The Madoka is Daikin's own room `thermostat'

matt_drummer

oliver1951 said:

matt_drummer said:

Spies said:

What's the overshoot value set to under Space heating on the MMI?

Overshoot is normally adjustable between 1c and 4c, but may not be depending on the heat pump, the heating mode chosen and the firmware installed on the heat pump.

My 8kW required a firmware update to make the adjustment possible in radiator mode, it was locked at 1c before the update.

Overshoot sets the amount the heat pump can exceed the requested flow temperature, either a fixed flow temperature or that determined by the weather dependent curve.

There is also modulation which is only adjustable once activated and only in use if using the Madoka to control room temperature. It is adjustable between 1c and 10c and is what is known as load compensation.

Neither of these setting will change what is going on with @oliver1951

What you are seeing is the hysteresis on the room temperature control. It is 2c and not adjustable.

If the room temperature is set at 20c then the heat pump will turn off at 20.5c and come back on at 18.5c.

I don't like it and it is one reason I don't use it.

You can make it take longer to get to the required room temperature by reducing heat output but once the required temperature +0.5c) has been reached the house has to cool by 2c before the heat pump will come on again.

It's uncomfortable for me and I wanted a constant heat.

I also found it inefficient in terms of COP.

The heat pump runs less but when it is running it uses more electricity at a lower COP.

So, if you want 20c, set it to 21c, it will heat to 21.5c and come on again at 19.5c

With regard to user profile, you can adjust very little as an advanced user (code 1234). You need to go into installer settings (code 5678) to make any real changes.

Hi Matt. I have the 8kw Daikin, same as yours. I have my temp set for 16c. The other day it was cutting in at about 15.9 and out and 16 and back in on 15.9. So no 2 degree drop. I’m going to have another try to get into the MMI and look at the settings. I have a hive controller, which doesn’t do a lot at all. When I spoke to hive, believe it or not, they couldn’t tell me what the drop back temp was , nor if it could be adjusted. Matt I can’t remember did you get your monitoring equipment installed by octopus or did you get it retrofitted? 

How do you have a Hive and a Madoka?

You can't have both.

oliver1951

matt_drummer said:

oliver1951 said:

matt_drummer said:

Spies said:

What's the overshoot value set to under Space heating on the MMI?

Overshoot is normally adjustable between 1c and 4c, but may not be depending on the heat pump, the heating mode chosen and the firmware installed on the heat pump.

My 8kW required a firmware update to make the adjustment possible in radiator mode, it was locked at 1c before the update.

Overshoot sets the amount the heat pump can exceed the requested flow temperature, either a fixed flow temperature or that determined by the weather dependent curve.

There is also modulation which is only adjustable once activated and only in use if using the Madoka to control room temperature. It is adjustable between 1c and 10c and is what is known as load compensation.

Neither of these setting will change what is going on with @oliver1951

What you are seeing is the hysteresis on the room temperature control. It is 2c and not adjustable.

If the room temperature is set at 20c then the heat pump will turn off at 20.5c and come back on at 18.5c.

I don't like it and it is one reason I don't use it.

You can make it take longer to get to the required room temperature by reducing heat output but once the required temperature +0.5c) has been reached the house has to cool by 2c before the heat pump will come on again.

It's uncomfortable for me and I wanted a constant heat.

I also found it inefficient in terms of COP.

The heat pump runs less but when it is running it uses more electricity at a lower COP.

So, if you want 20c, set it to 21c, it will heat to 21.5c and come on again at 19.5c

With regard to user profile, you can adjust very little as an advanced user (code 1234). You need to go into installer settings (code 5678) to make any real changes.

Hi Matt. I have the 8kw Daikin, same as yours. I have my temp set for 16c. The other day it was cutting in at about 15.9 and out and 16 and back in on 15.9. So no 2 degree drop. I’m going to have another try to get into the MMI and look at the settings. I have a hive controller, which doesn’t do a lot at all. When I spoke to hive, believe it or not, they couldn’t tell me what the drop back temp was , nor if it could be adjusted. Matt I can’t remember did you get your monitoring equipment installed by octopus or did you get it retrofitted? 

How do you have a Hive and a Madoka?

You can't have both.

I don’t have both I only have a hive, plus in case it’s causing confusion the MMI, but no madoka. The hive is essentially the thermostat and it allows scheduling too. Pretty much like the madoka I imagine. My install was done by British Gas. Hive is owned by Centrica, which also owns British Gas , I guess that’s why I got the hive.

matt_drummer

oliver1951 said:

matt_drummer said:

oliver1951 said:

matt_drummer said:

Spies said:

What's the overshoot value set to under Space heating on the MMI?

Overshoot is normally adjustable between 1c and 4c, but may not be depending on the heat pump, the heating mode chosen and the firmware installed on the heat pump.

My 8kW required a firmware update to make the adjustment possible in radiator mode, it was locked at 1c before the update.

Overshoot sets the amount the heat pump can exceed the requested flow temperature, either a fixed flow temperature or that determined by the weather dependent curve.

There is also modulation which is only adjustable once activated and only in use if using the Madoka to control room temperature. It is adjustable between 1c and 10c and is what is known as load compensation.

Neither of these setting will change what is going on with @oliver1951

What you are seeing is the hysteresis on the room temperature control. It is 2c and not adjustable.

If the room temperature is set at 20c then the heat pump will turn off at 20.5c and come back on at 18.5c.

I don't like it and it is one reason I don't use it.

You can make it take longer to get to the required room temperature by reducing heat output but once the required temperature +0.5c) has been reached the house has to cool by 2c before the heat pump will come on again.

It's uncomfortable for me and I wanted a constant heat.

I also found it inefficient in terms of COP.

The heat pump runs less but when it is running it uses more electricity at a lower COP.

So, if you want 20c, set it to 21c, it will heat to 21.5c and come on again at 19.5c

With regard to user profile, you can adjust very little as an advanced user (code 1234). You need to go into installer settings (code 5678) to make any real changes.

Hi Matt. I have the 8kw Daikin, same as yours. I have my temp set for 16c. The other day it was cutting in at about 15.9 and out and 16 and back in on 15.9. So no 2 degree drop. I’m going to have another try to get into the MMI and look at the settings. I have a hive controller, which doesn’t do a lot at all. When I spoke to hive, believe it or not, they couldn’t tell me what the drop back temp was , nor if it could be adjusted. Matt I can’t remember did you get your monitoring equipment installed by octopus or did you get it retrofitted? 

How do you have a Hive and a Madoka?

You can't have both.

I don’t have both I only have a hive, plus in case it’s causing confusion the MMI, but no madoka. The hive is essentially the thermostat and it allows scheduling too. Pretty much like the madoka I imagine. My install was done by British Gas. Hive is owned by Centrica, which also owns British Gas , I guess that’s why I got the hive.

Oh dear.

Some of the features of the Daikin heat pump won't work without the Madoka.

They may well own Hive but it's a Daikin heat pump.

I know it has provision for third party controllers but most installers would choose the Madoka.

You probably won't have the modulation feature available in the MMI.

Spies

So can you not have weather comp and modulation at the same time? 

matt_drummer

Spies said:

So can you not have weather comp and modulation at the same time? 

You can with a Madoka.

You can set a weather dependent curve for the heat pump set in the MMI.

I haven't tried it, obviously, but I am pretty certain that you can only have modulation (load compensation) using the Madoka controller with a Daikin heat pump.

I don't see any way that a third party controller could integrate with the heat pump controls sufficiently to control anything more than on or off.