Posted by: @batalto

↑

@hughf yeah its annoying its not accurate. At the moment I am using the figures as a gauge to see how the system is working. I considered using emconpie - but I cant be bothered. Realistically lower flow temps = more efficient and its that simple. Unless someone wants to send me the kit, then I'll install it.

The other available option for more accurate (possibly?) monitoring with Midea units is FHP Cloud...

@hughf honestly I don't know anything about it. Any details?

@batalto 

All I know is: "

@batalto I didn't realise you could build your own batteries, I'll have a search for this on you tube but assume it would then need new inverter and qualified electrician to fit?

Posted by: @hughf

↑

an incredibly simple to install piece of hardware

I mentioned this very quote not so long ago. You can actually log onto the Headroom Heat Pumps dashboard but it shows no data, I guess because it has no way of tying your login to your data. I'm guessing that your installer has to buy into the app, and then set things up so you can see your data. But most of the interesting data is on the installer dashboard. The login page is here <-link. All you need is an email address and you can then sign up.

As for "an incredibly simple to install piece of hardware"... if it is so simple, why be so cryptic? 

Posted by: @cathoderay

↑

As for "an incredibly simple to install piece of hardware"... if it is so simple, why be so cryptic? 

It might be useful for other purposes but sold at insufficient markup for them to want random DIYers buying it.

Posted by: @benseb

↑

It’s also worth remembering the oil or gas boilers have very expensive days too. It was just harder to measure. 

I remember during beast from the east getting through an entire 1100L tank of oil in 3 weeks. At todays prices that’s about £1000 in 3 weeks. 

Thankfully these cold spells are short lived. Saying that if they were more common maybe installers would pay more attention to good design!

Which is why you should Insulate, Insulate, Insulate, and then add more insulation.

Posted by: @cathoderay

↑

Posted by: @benseb

↑

You might be more successful at a lower temp.

I doubt it, the system was designed with a flow temp of 55 degrees. Lack of available wall space for rads was a major constraint, necessitating a higher than ideal flow temp, But, as designed, the system needs these flow temps, any lower and the rads will not put out enough heat.

I agree it is absolutely a whole system thing, ASHP => circuits => emitters, as I have said many times. Each part of the system needs to do its bit. As designed, the rads can put out enough heat at 55 degrees flow, the weak link in the system is the heat pump which does not put out the 12.4kW plus headroom claimed by Freedom. It's going flat out, and doesn't get the system up to design flow temp.

For anyone wondering whether I am going to flip the dips, the answer is not yet, because doing so is bound to increase consumption, and as I am already using ~100kWh a day, I really don't want to push that up any further. I'd rather put on an extra layer of clothing. The point under discussion here is whether the heat pump as part of the designed system is adequate or not, not what I do if it turns out it isn't adequate.    

I would suggest that you have a word with Trading Standards, since your present system does not appear to achieve the specified output as per the design documentation.

When I first started researching ASHP's, I quickly came to the conclusion that the specified maximum output capacity of a heat pump, would need to be between 1.25 and 1.5 times the calculated heat loss for the property. Below 1.25 it may struggle to supply the heat demand, and above 1.5 it would increase the likelihood of cycling during milder weather conditions.

From their published data, it would appear the Midea units are particularly poor at meeting the required output during cold weather conditions.

@kev-m - I've extracted and tidied up the Midea 14 and 16kW data from the Engineering Data handbook.

Posted by: @derek-m

↑

From their published data, it would appear the Midea units are particularly poor at meeting the required output during cold weather conditions.

This does indeed seem to be the case.

I am reluctant to involve Trading Standards because any complaint I have is not with my installer, who did what he could in good faith, and I am extremely grateful to him for doing that, otherwise I would have missed the grant deadline, but with Freedom for putting out a spreadsheet with made up data, which is the root cause of the problem. The fact it is a grant funded installation also no doubt complicates things - who is the contract actually with etc. Another ASHP/grant related minefield...   

@bretix you still need a hybrid inverter, but you would anyway. No you don't need a qualified electrician to fit it. I have a thread about my experience building the Seplos battery in another thread. Just have a look

Posted by: @cathoderay

↑

Posted by: @derek-m

↑

From their published data, it would appear the Midea units are particularly poor at meeting the required output during cold weather conditions.

This does indeed seem to be the case.

I am reluctant to involve Trading Standards because any complaint I have is not with my installer, who did what he could in good faith, and I am extremely grateful to him for doing that, otherwise I would have missed the grant deadline, but with Freedom for putting out a spreadsheet with made up data, which is the root cause of the problem. The fact it is a grant funded installation also no doubt complicates things - who is the contract actually with etc. Another ASHP/grant related minefield...   

Your complaint should actually be against Midea and Freedom, since the data clearly shows that a 14kW labelled heat pump, cannot deliver 14kW of heat energy when it is required to do so.

Did you find out how much efficiency you are losing due to the installation of the PHE?