Joining the Renewable Heating Hub forums is completely free and only takes a minute. By registering you’ll be able to ask questions, join discussions, follow topics you’re interested in, bookmark useful threads and receive notifications when someone replies. Non-registered members also do not have access to our AI features. When choosing your username, please note that it cannot be changed later, so we recommend avoiding brand or product names. Before registering, please take a moment to read the Forum Rules & Terms of Use so we can keep the community helpful, respectful and informative for everyone. Thanks for joining!
Last seen: Oct 19, 2026
@heatgeek I feel this may all be heading towards a conclusion that there are a set of trade offs in compressor modulation range and cycling. Without ...
Thanks for that. The ecoforest graph of cop Vs compressor speed explains a lot. Perhaps it even explains how Daikin appear to do a single compressor...
1.8kW is at 7C, the more interesting figure I think is the min at say 12-15C. That doesn't appear to be specified for the Hitachi, but for the heat p...
@heatgeek @robs I was going to say exactly what @robs has said. The interesting metric is the ratio between min output at high OAT/low FT and max ou...
2 port buffer/volumiser is fine, will help with defrost/system volume and no downsides. 2 ports good, 4 ports bad! The general rule for rads is to ...
The full sentence was "larger radiators = lower flow temperature and larger system volume. The latter certainly would be expected to reduce cycling...
Thank you for pointing that out, I should have commented on this also (but as you say there is a lot here). I did note this comment, am not disputing...
Further to the above I discovered a bit more/had an additional thought about Daikin compressors. Firstly Daikin do make their own compressors so its ...
I must say Im also coming to the conclusion that there is a problem of this nature. OP has optimised the initially high flow temperature and its now ...
Very much agree. I think OP is over-concerned about this because, as you say, cycling is 'designed in'. Also very much agree We may be spli...
'and thus its capacity' assumes that output is a linear function of modulation frequency. But I dont think thats the key point so lets not argue over ...
Aren't you potentially confusing two things here. OP could of course increase rad size/ volume and reduce ft but that won't change the minimum output...
SPONSORS
Degrees of Separation
Latest Posts
-
RE: How quickly would you want/expect heat recovery to take from setback?
@jamespa And ‘Decorator’s Caps’ are relatively cheap an...
By Toodles , 1 hour ago
-
RE: Renewables & Heat Pumps in the News
@majordennisbloodnok Best we keep that trident well pol...
By Toodles , 1 hour ago
-
RE: Renewable Heating Hub Homeowners' Q&A Podcast
Come for the low-carbon homes. Stay for George Clarke’s...
By Mars , 1 day ago
-
RE: Octopus Cosy 12 Heat Pump Regret: Incredibly Loud, Poor Heating & Constant Hum - Help!
@razz, as we head into the heating season, I just wante...
By Mars , 1 day ago
-
RE: How should the Boiler Upgrade Scheme be reformed?
Not quite, regular A2W heat-pumps need a load of extra ...
By Temperature_Gradient , 3 days ago
-
RE: Heat Geek installations: share your experiences
one thing i learnt from reading people’s comments and e...
By Batpred , 3 days ago
-
RE: Cooling/heating with one unit
"The way we use A2A on a cheap overnight EV tariff is t...
By mrkfm , 3 days ago
-
RE: Do I add Air Con or MVHR to existing A2W ASHP?
We have ‘signed on the dotted line’ today for a Panason...
By Toodles , 3 days ago
-
RE: Heat pump branding. Clever, contemporary… or a bit too much?
...or it was there and was lost thanks to laziness and ...
By Majordennisbloodnok , 3 days ago
-
@bobflux Thank you for your response. I am trying to ...
By RonV. , 3 days ago
-
Bufferless design & control of Chinese air to water monoblock hybrid heat pump in Alberta, Canada
This post is about how I successfully configured a buff...
By Tony.Stolz , 3 days ago
-
The installer visited yesterday and suggested the noise...
By JamesChatz , 3 days ago
-
RE: HeatGeek vs Octopus surveys: puzzling disparity - any ideas why?
Your house sounds a lot like mine. 2 surveyors each sp...
By JamesPa , 3 days ago
-
RE: Heat Geek Zero Disrupt: Are We Sleepwalking Into Another Race to the Bottom?
Thats true only if you do the wrong experiment. Done c...
By JamesPa , 3 days ago
SPONSORS
