To make you think, ...The new "white gold"-rush of badly trained heat pump engineers & the deluded public.

[Mr Gus]

Please bear in mind this video is a year old at least, so pre-dates the current energy mess slightly.
You'll want to play devil's advocate & not seem him a complete moaner, because we know th cash machine govt install plan can foul up tech, as can what expectations you are *sold* compared to empirical reality where UK housing is concerned.
It reminds me of what we were /are faced with with EV''s use, perception & mal-treatment via DNGAF media wonks.I

However it may also serve to focus folk on core room heating, upgrades etc.

[Mr Gus]

You may wish to follow up with this... (Irate engineers countering the 1st video)


Suffice to say, I like heat pumps, many folk don't want to do any leg work to upgrade & keep knocking back bills via small improvements (not talking whole of house expenditure) ...sadly dishonesty & desire for a fast buck (govt pay out from filed paperwork permitting) will be a lot of airtime spent on disgruntled pump owners with only half the job done & half the info given .

[Oldgreybeard]

Took me a couple of months to get our heat pump working properly. As installed the settings were way out from those that were needed to avoid it costing an arm and a leg to run. The installer was completely clueless and just left it on the default settings, which were seemingly designed for operation in the Arctic.

Luckily there was a discussion about heat pump settings on another forum, and some people there had discovered how to adjust things to improve efficiency. I basically followed that guidance, although it was far from easy to find the settings to adjust, and after a lot of fiddling got the thing working about 30% more efficiently than it was when installed. I did then contact the installer to tell him what I'd done. To his credit he came out and had a look, making a note of the adjustments I'd made and commenting that they hadn't told him about any of this stuff when he did the course.

[richbee]

they hadn't told him about any of this stuff when he did the course.

That about sums it up doesn't it - no investigation, reading, understanding - just 'do the course' and hey presto you're an expert!
Seems the same with my solar installers - no idea how to set it up, or what the different options do - "computer says no"

[Mr Gus]

Difference being with OGB & members here, we care enough to find a fix rather than bleat (beyond ourselves as a helpful forum ) ...compared to the dumb / feckless / incapable.

Please watch both vids folk, don't think I'm having a pop at technology, we have seen how these things end before.
Apparently there are a few videos of this guy doing video rants ..a veritable cash machine just like a fake snake oil / religion peddlar can be via the modern platforms available.

[Oldgreybeard]

TBH, if I hadn't spotted that the heat pump was running lots of defrost cycles I would probably not have bothered to look into it, but would have just accepted that it was pretty crap in terms of efficiency. As installed, even in mild weather, the thing was defrosting about every ten to fifteen minutes. When it does this it goes into reverse, pumping heat out of the house and into the heat pump to melt the ice. Seeing warm water getting sucked out of the house and used to melt ice in the heat pump didn't seem to me to be a good thing.

The changes I made to the settings were fairly simple, reduce the flow temperature to a fixed low value, just warm enough for the heating and no warmer (I settled on 35°C) and turn off the daft weather compensation feature, that increased the flow temperature in proportion to decreasing outside temperature (completely bonkers for underfloor heating, where the UFH system regulates the temperature with it's own thermostatic valve anyway). These two changes transformed the performance of the heat pump. Now it very rarely ever runs a defrost cycle, about the only time it does it if it happens to be a cool and very damp night.

[Stinsy]

I've heard that undersized ASHPs do particularly badly in the UK's humid climate because they ice-up quickly when working hard. An over-sized ASHP idling along at its minimum power level doesn't ice-up and therefore doesn't need to act as an aircon to defrost itself (as often).

[Oldgreybeard]

I've heard that undersized ASHPs do particularly badly in the UK's humid climate because they ice-up quickly when working hard. An over-sized ASHP idling along at its minimum power level doesn't ice-up and therefore doesn't need to act as an aircon to defrost itself (as often).

Our's was designed to be over-sized for that very reason, but that played no part at all in the core icing problem. The issue was that the unit was being asked to deliver too high a flow temperature and whenever the air is humid that makes it ice up. here in the South West we're not exactly known for having a dry climate, so the icing happened with monotonous regularity.

In my case the default setting was a flow temperature of 55°C at an outside temperature of +10°C, rising to a flow temperature of 65° at -5°C, due to the weather compensation characteristic. These were the default settings from the factory, and to change them meant getting access to the installer menu (password protected) and then wading though about 30 or so different settings, only identified by a serial number.

We have underfloor heating and the installer new that, as he connected it all up. I believe that the default settings are intended for use with radiators, judging from the temperatures. The installer wasn't aware those settings existed. yet he knew full well that the thermostatic valve on the heating is set for 32°C, so there was no point in feeding it with water at 55°C or even higher in cold weather. The other big advantage of turning the flow temperature down is that the heat pump now stays on, at a low power level, for a great deal longer, instead of cycling on and off as it did before. I'm sure a lot of the cycling was because it was pushing water at far too high a temperature to the heating, which was then shutting down its thermostatic valve a lot and restricting flow.

[Oliver90owner]

I suspect the COP claims are for dry air (and minimum temperature differences - don’t take into account periods of defrost. Simple marketing/sales hype, I expect.

Advertising, using Nordic country use, can also mis-inform. There is very little moisture in the air below freezing point.

I await some reliable, real world figures where the expense is justified.

[Mr Gus]

Agreed Oliver, any marketing blurb / April needs to be pertinent to the country & maybe even regional variants summarised with all the general weather data to hand rather than shooting from the hip about other countries which smacks of deceit or contemptible ignorance of a sales team.

"I'm recording this for fact checking purposes" would scare the bejeesus out of strong arm selling practitioners.
I'm afraid the energy rush is going to have a lot of people seeing themselves as victims regardless of whether they are handed helpful paperwork that they couldn't be bothered to read & digest either though, nature of the beast.