“More savings could be made by looking at the forecast and "charging up" the thermal stores of a building now if it's going to get colder later”

The outdoor sensor is a forecast of the indoor temperature as heat leaves the building slowly.

“The adaptive/"smart" learning controls I've seen seem aimed at learning more precisely how fast the building loses heat and warms back up, with the aim of more precise target temperature tracking, rather than minimising the cost of keeping the temperature in some acceptable range.”

It’s all there even in the U.K. on some manufacturers. I see it all the time!

Posted by: @alec-morrow

“More savings could be made by looking at the forecast and "charging up" the thermal stores of a building now if it's going to get colder later”

 

The outdoor sensor is a forecast of the indoor temperature as heat leaves the building slowly.

Well, yes, but we also have forecasts of the outdoor temperature (and so the future efficiency of the heat pump) that most controllers ignore at present.

Posted by: @mjr

More savings could be made by looking at the forecast and "charging up" the thermal stores of a building now if it's going to get colder later, and by depleting the thermal stores if it's going to get warmer later which will make it easier to recharge the thermal store and warm the air temperature back up. A sort of second-order weather compensation which considers the rate/direction of change of temperature as well as the current temperature.

Then even more savings may be possible by considering the expected cost of the energy driving the heat pump, whether through something like an Agile tariff, predicting solar PV output or even good old Economy 7.

I'm not sure much work is being done on this yet.

The only system I know that does all of this is Homely from Evergreen Energy. It’s an IoT/Cloud based flow temperature controller for Midea and Samsung heat pumps, that talks to them over modbus-rtu (rs485).

It knows electricity spot pricing, weather forecasts for your geolocation, and indoor air temp/humidity. It can be set to load compensate if that’s beneficial to recover from a setback temp.

Quite a nice product on the face of it.

Posted by: @derek-m

@editor

Apparently our present government don't think that it is important for people to reduce their energy consumption, just to use it at a different part of the day. 

I found the decision not to request people to reduce energy consumption astonishing. Not only will it help the grid, but it’ll save people money. A very, very strange decision. This winter, for us, is going to be a major exercise in saving energy and not using excess amounts.

Posted by: @hughf

The only system I know that does all of this is Homely from Evergreen Energy. It’s an IoT/Cloud based flow temperature controller for Midea and Samsung heat pumps, that talks to them over modbus-rtu (rs485).

It knows electricity spot pricing, weather forecasts for your geolocation, and indoor air temp/humidity. It can be set to load compensate if that’s beneficial to recover from a setback temp.

Quite a nice product on the face of it.

Just a bit of a shame it's a subscription service and an undocumented black box.

Maybe something like this should be bought by whatever bit of government is responsible for energy efficiency now, open-sourced and documented, so it could be rolled out to all heat pumps more quickly? No chance under Truss, but I think I remember Starmer announcing a "Great British Energy Company" if (when?) he wins the next election.

I think, on paper, this sounds like a great and useful system. For me, I don’t understand why all big make heat pump manufacturers don’t have intelligent and highly effective weather compensation built in as standard. 

@editor

If my understanding is correct, I believe that most manufacturers have inbuilt weather compensation, along with indoor temperature control.

The problem would appear that the required sensors are either not installed, or are installed in the wrong place. The system also needs to be correctly configured and optimised.

Just as they often state in the world of computing, 'garbage in - garbage out', it is the same with control systems. The most sophisticated, and often expensive, control system in the world, will not produce the desired level of control unless it is supplied with the correct information, and correctly configured and optimised.

The control system that I installed to control our old gas boiler, which does not have any form of weather compensation, consists of a PID Controller and two RTD Temperature Sensors. It can control the indoor temperature to +/- 0.2C under varying weather conditions. I did contemplate installing a third temperature sensor to measure the outside air temperature, which would probably provide control to +/- 0.1C, but decided it was not necessary.

Whilst there are a few who like to experiment with new technology, I think that the vast majority would just like a control system that works with the minimum of human intervention, and does not cost an arm and a leg to both install and run.

I have been contemplating writing an article on how to design and develop a control system for an individual's requirements, but so far have managed to resist the urge. Maybe sometime in the furure?

Posted by: @derek-m

I have been contemplating writing an article on how to design and develop a control system for an individual's requirements, but so far have managed to resist the urge. Maybe sometime in the furure?

im afraid the world doesn’t need another control system i’m afraid, it needs people who understand, install and commission..

@alec-morrow

I am not suggesting a different type of control system. What I am highlighting is the need to correctly design and configure the correct control system for each individual home, utilising the systems and equipment already available.

The starting point is to first of all specify what it is that you wish to achieve, what is the primary objective. Does one wish to keep the indoor temperature as constant as possible, or keep the energy consumption as low as possible, or keep the running cost as low as possible? It may be possible for one or more of these objectives to be achieved, but not necessarily all of them at the same time. Does one want a system that varies how it functions dependent upon the time of year and the weather conditions? Should it make any changeover automatically or require human intervention?

Should any sensors be wired or wireless? Where should the sensors be located?

All of these factors will affect the choice of equipment, its location, and how it is configured to operate.

As you have correctly pointed out, many of the personnel within the heating industry do not appear to have the necessary knowledge and skills to be able to carryout these tasks. Much of the equipment and systems already exist, it just a matter of finding and/or training the people that know how to use it.

Posted by: @derek-m

The problem would appear that the required sensors are either not installed, or are installed in the wrong place. The system also needs to be correctly configured and optimised.

That’s spot on Derek. All heat pumps have weather compensation. Ours too, but it’s disabled because the central control panel was installed in the wrong place… installer issue - AGAIN. This is a recurring theme.

I’m manually dropping our flow temperature at the moment because at 45C the house is boiling. Currently running at 38C. To be frank, there’s very little difference in electricity consumption though. 

@derek-m, I think writing an article would be a great idea. I strongly feel we need better information for homeowners to force installers to do jobs properly. There are just too many cowboy installer outfits out there that are installing systems that aren’t fit for purpose.

Grading our original install, it was about 70% right and that lacking 30% is playing a massive role in efficiencies and higher running costs. That’s simply not good enough, so the more instruction we can give homeowners to be able to request things from installers that’ll make their systems run more efficiently the better for everyone.