@cathoderay - Below is the technical manual

MIDEAUK.CO.UK "https://mideauk.co.uk/wp-content/uploads/2020/09/TM_Midea_A-series-Mono_M-Thermal-Heat-Pump_20200430_V1.pdf"

Password - midea2020

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@batalto - brilliant, you are a hero! It looks like S6 is upper mid position on the MAIN BOARD in the drawing just above the one showing the switch settings. But it still leaves the question: why didn't Freedom make use of/tell us about this option when we asked for a 16kW unit, and they (thought they) only had a 14kW unit? Perhaps detailed understanding of Midea units left when @grahamh left? That might explain why they are reluctant to talk to end users (the deficits will become too obvious?). 

@cathoderay I imagine they charge more for the "bigger" unit - I have the 12kw unit and didn't know that I could change the power until Graham said. I don't need to, as the house is plenty warm, but it nice to know should it get really really cold that I can bump up to 16kw by just flicking a switch (or two)

@batalto - see what I said about the price diffs a couple of posts ago - there is a difference, but it is not very much, which fits with same hardware, price diff is really only there to make it seem the units are inherently different.

It's curious Midea don't make this flexibility widely known, and use it as a marketing point. It might go over Mr and Mrs Average's head, but for installers, and involved end users like us, it is a definite plus point. But I suppose @grahamh's point that marketeers worship at the altar of many models wins the day.     

@cathoderay yes, even if they charged extra for the uprating to cover increased warranty costs from increased mechanical failure probabilities due to it, the easy upgrade option would be a big selling point,what with how many horror stories there are of huge houses stuck with undersize pumps.

@mjr - agreed.

Here's a photo from the M-thermal service manual (I will try and track down where I got it from) showing two things:

(a) S6 where we expect it to be (red arrow points to it)

(b) the 12/14/16kW units all use the same main board.

Rather bizarrely, I got the M-thermal Service Manual from Freedom's website:

https://www.freedomhp.co.uk/downloads/28c99c95-0052-4e20-9916-7f2ffbed471e

Bottom of the list on that page, click on the box on the left to select, right click to download.

Posted by: @cathoderay

@batalto - see what I said about the price diffs a couple of posts ago - there is a difference, but it is not very much, which fits with same hardware, price diff is really only there to make it seem the units are inherently different.

It's curious Midea don't make this flexibility widely known, and use it as a marketing point. It might go over Mr and Mrs Average's head, but for installers, and involved end users like us, it is a definite plus point. But I suppose @grahamh's point that marketeers worship at the altar of many models wins the day.     

But you would expect the supplier of said ASHP range to know something so basic, and useful. It all looks a bit fishy to me. If only the end user were the most important link in this long chain.  Or maybe at the centre, with everyone working in their interest.

Posted by: @grahamh

@derek-m all good points but since almost no one reads the instructions they dont know the capacities can be changed. 

No manufacturer will ever tell you you can do it either, why would they? Rebadging the same units means you can have a big range which is an industry obsession. 

its common in most industries, in the car world you can buy a car with or without cruise control, all of them have it but if you take the option they activate the software (for a fee) if you dont they dont. 

 

a look under the bonnet or lid confirms that the units are identical, or a look in the spare parts list. something dullards like me like to do. 

For ref from the MCS database: The Mitsi 14kW scop at 50c is 3.3 the Midea 3.59. not surprising the Midea is a much newer unit. 

Hi Graham,

I have just had a quick look on the MCS site and could not find Midea in the list, is it under some other name?

@derek-m - it's just another example of MCS obfuscation. They don't use Midea in the product name. You have to search for the model number. If you search under 'Product' for 'MHC' you will get a list of Midea units, only you won't know they are Midea units until you click on one, and look at the details. I can't provide a direct link to the models because of the way the MCS webpage works, but you can do the search here:

https://mcscertified.com/product-directory/

The MHC-VxxW/D2N8-B models are the relevant ones, where xx is the nominal output in kWs. You can see how easy it would be for MCS to add outputs at various ambients to the Flow temp/SCOP table.    

I haven't changed any settings yet, just making observations, and some of them are pretty odd. 

I started trying to get a baseline instantaneous COP. This is supposed to be straightforward on a Midea, one of the Operation Parameter pages shows Heat Pump Capacity (ie output) and Power Consum(ption). Divide the former by the latter and you get the COP at that moment, only you don't. When the compressor is running, the former fluctuates quite a lot, but seems to average out at around 5 to 7.5 kW (although sometimes it's less), but the power consumption hovers around 1000kWh. So if that was kW not kWh, that would be a COP of 0.005 to 0.0075. But it is showing not kilowatts but kilowatt hours and it may be 'hovering around 1000' because it is actually a energy supplied meter, and yesterday it was 990 something and today it is just over 1000.

Ambient temp outside is 6 degrees, LWT is 51 degrees: on the Midea Engineering data output tables, the output (capacity) should be over 10kW. The rooms are struggling to get to design temp, some are, some aren't. At 6 degrees ambient, we haven't even got into the defrost cycle penalty zone, yet the unit seems to be struggling, and not putting out the kWs it should. 

On another page the controller show Comp(ressor) Current. This also varies, but currently shows 10A. 10A x 240V = 2400W, my £££££ ASHP is putting out not much more than a £20 Argos fan heater...

None of this makes much sense. Can anyone explain what is going on?

cathodeRay    

@cathoderay I'd advise you get the midea app and just find the data directly from that. It's on the app store and called "msmartlife"