Posted by: @papahuhu

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The homely is running the weather compensation instead of the heat pump controller, so as the outside air temp increases the flow temp will be decreased as the house will be shedding heat at a lower rate.

I was aware that Homely is doing that, what I've noticed is the flow temperature running lower that it has done previously. It is running about 5 degs lower than I have ever seen it running at before. I wondered if it was only my HP that is running cooler or if there was a noticeable difference for others too.

@johnnyb 

I’m not saying that you are wrong. 
However, assuming you haven’t changed the target temp or target time and your flow rate has remained constant, your house is loosing a certain amount of heat at a certain delta T between inside and out, per unit time. 

Assuming your heat pump is in constant operation, it’s impossible that it is running at a lower flow temp at the same outside temp as before and still satisfying the same heat demand. To be doing so would be breaking the first law of thermodynamics, so something else must explain the observations you are making, likely a change that you haven’t yet noticed. For example differences in solar gains or wind speed or wet brickwork from driving rain causing evaporative heat loss. 

@papahuhu Neither of us are wrong, the HP isn't running full time. We live in a well insulated new build and have a 5kW HP with a heat loss that is half that so the flow temperature can be lower and the HP run for longer.  Even when it is very cold outside our HP doesn't run all the time, and the WLT is set to a max of 35degs so we don't have high flow temperatures even when it is very cold.

I thought Homely was known for not running all the time but raising the temperature 1-3 degs when it is cheaper or more efficient to do so then letting it drop back to the set point when the electric is more expensive.

@johnnyb It depends what mode you are running on and what tariff you tell it you are on and how the machine learning has decided to heat your house from the first 20 days performance.

For example, I run from a battery which acts as a buffer between heat pump and the tariff, and run “smart” mode, intentionally not “smart+” mode. So from the heat pumps perspective it’s a flat tariff, even though it is objectively a time of use. 

If you are on “smart+” then yes, it will over and under heat to minimise cost rather than consumption. I’d imagine it would negatively impact COP too, but remain cheaper.

@papahuhu My feeling is that Homely had been overthinking when deciding on the algorithm for Smart+. I have had a number of conversations with various personnel at Homely on this very subject.

It seems that they have ‘downplayed’ the comfort factor in favour of the COP optimisation for TOU tariffs. I explained to them that overheating for an hour or two to enable reducing higher cost energy consumption did not really suit our requirements. I also explained that although we were using a TOU tariff, we used a buffer in the form of a battery so using the energy at the time of most need didn’t incur the higher rate(s) of the tariff.

By the way, I haven’t yet heard about the recent(ish) trial of updated soft/firmware that I may or may not have participated in. I say ‘may or may not’ as I understand opting for the trial may have meant my Homely controller was particpating or might have remained as part of the ‘control’ group. Regards, Toodles.

@toodles 

The TOU functionality is tricky, but for those without a battery and on a tight budget I can see a little bit of overheating a reasonable compromise to keep heating costs down. Everyone has their unique priorities, for me I most object to the warm bedrooms, if I knew I was unable to set them back effectively I’d never have agreed to install it. The thought of yet additional overheating to capture the cheap overnight power tariffs makes me cringe. 

Posted by: @toodles

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It seems that they have ‘downplayed’ the comfort factor in favour of the COP optimisation for TOU tariffs.

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It's not surprising, though.

Using a home as a heat battery does allow them to claim financial savings and financial savings look good on marketing literature. Financial savings are also something most potential customers immediately understand whereas having to live in a sweatbox isn't as immediately obvious until the controller and Smart+ subscription have been bought.

Posted by: @johnnyb

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I was reading your thread about your change from Homely to HA at the weekend and I would like to do something similar once I have time, but that is a way off at the moment so Homely is an easy option. 

I would definitely recommend it. Now that I think I have nailed my settings, it is better all round really- cost and comfort-wise without homely. Looking at this month already my consumption is on track to be under what March 25 was. COP for the whole of March 25 was 3.2 (and looking at the historical local weather data it was quite warm for the second part of that month), and COP currently for this March is 4.2. 

@benson But I have got a homely and I haven’t done anything to optimise it and I checked yesterday and my overall Feb COP was 4.2 and March COP to date was 5.3 and improving week on week. So I’m not sure it’s necessarily accurate to assign blame on one component of the overall install.

I suppose it’s also a possibility that it might be even more efficient without the homely, it’s just I’ve never tried. 

@papahuhu I haven't changed anything with my install other than removing homely- with the exception of one small bedroom radiator upgrade (one out of the 16 or 17 emitters that I have). Thus yes I blame homely for hampering my efficiency and my comfort and I have provided the evidence for this.

Your house, and ashp, is completely different to mine, thus comparing COP is meaningless. I'm not aware of anyone else who's done the direct comparison that I have with and without homely, so just sharing my experience. 

Posted by: @papahuhu

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I suppose it’s also a possibility that it might be even more efficient without the homely, it’s just I’ve never tried. 

Worth trying perhaps. Time saving in commissioning with some units is definitely the USP of something like homely, no doubt about that. 

@benson I’d like to try. But for the Samsung, because it isn’t web enabled off the shelf,  there is additional electronic hardware added to the outside unit and internal controller. If I start taking out resistors and PCBs I’m going to void my warranties. I can’t take that risk.