BartW Posted January 22, 2022 Author Share Posted January 22, 2022 48 minutes ago, Dan F said: Mixergy doesn't have a built-in bottom coil as they recommended a different approach for using ASHP with an external PHE See: https://www.mixergy.co.uk/mixergy-heat-pumps-faqs/ This however, is not the approach I'm using, as aroTherm means the limitations mentioned here do not apply. This two-pager does a good job at summarizing the different approachs: https://www.dropbox.com/s/9091d4a0ut7i5am/Heat pump leaflet V1_compressed.pdf?dl=0 Ok, I thought the heat exchanger was fitted as standard, as per the below: 49 minutes ago, Dan F said: Yes, but you need to look at the operating range too. The ones I looked at could only supply 60C between 0-25C which I felt was a bit too tight given the approach I was planning to take. Unless I am happy to keep it running at a lower temp, right? That's what the Mixergy say on their website. Hmm... 50 minutes ago, Dan F said: ROI from a pure energy usage perspective doesn't add up, unless you have very loong showers. But if you consider it's "greener" to recover rather than waste heat and it means you can get by with a smaller UVC, it did start to make sense from our perspective. (we didn't care about SAP, as house should score very high anyway). That's true. By the way, how have you got your Zyphos connected? Are they direct to the mixer, or teeing into the primary heat circuit? Link to comment Share on other sites More sharing options...
BartW Posted January 22, 2022 Author Share Posted January 22, 2022 2 minutes ago, SteamyTea said: Yes. I am not that far from Bicester ATM. Shame I cannot read them when I am driving home. Could get the whole set done during the 12 hours I am wasting every weekend. Oh dear, best don't read this if driving We live on site, so come for tea next time you are around 12hrs every weekend sounds like fun. Are you doing coast to coast? Link to comment Share on other sites More sharing options...
SteamyTea Posted January 22, 2022 Share Posted January 22, 2022 1 minute ago, BartW said: 12hrs every weekend sounds like fun. Are you doing coast to coast? Coast to about the furthest inland. I come from near Penzance. Link to comment Share on other sites More sharing options...
BartW Posted January 22, 2022 Author Share Posted January 22, 2022 9 minutes ago, SteamyTea said: Coast to about the furthest inland. I come from near Penzance. Ouch, I bet that hurts. Bicester to Penzance is about 5 - 6hrs. Newcastle is 5 Horus north from here. Done both as single journeys. It was tiring to say the least... Link to comment Share on other sites More sharing options...
SteamyTea Posted January 22, 2022 Share Posted January 22, 2022 2 minutes ago, BartW said: Newcastle Closer to me than home. When I lived in Watford, my g/f bought a 4 quid item from Newcastle. Drive there and back on s Sunday to pick it up. The tosser that we got it from did not even offer us a cup of tea. Still, got to see the Angle of the North. Link to comment Share on other sites More sharing options...
Dan F Posted January 22, 2022 Share Posted January 22, 2022 51 minutes ago, BartW said: Ok, I thought the heat exchanger was fitted as standard, as per the below: Standard on their heat-pump variant. All tanks now have these ports though, so it can be added later if needed. 51 minutes ago, BartW said: Unless I am happy to keep it running at a lower temp, right? That's what the Mixergy say on their website. Hmm... Maybe, but they have a pretty strong recommendation regarding the need for 60C primary flow for use of the top coil. You might get away with 55C if you don't plan to heat tank to more than 48/50C, but Mixergy won't recommend that. 51 minutes ago, BartW said: That's true. By the way, how have you got your Zyphos connected? Are they direct to the mixer, or teeing into the primary heat circuit? Do you mean the WWHRS? Directly into the mixer. It's not the most efficient setup, but it's by far the easiest as showers don't need to be near the UVC. Link to comment Share on other sites More sharing options...
BartW Posted January 22, 2022 Author Share Posted January 22, 2022 47 minutes ago, Dan F said: Standard on their heat-pump variant. All tanks now have these ports though, so it can be added later if needed. Sorry I meant to say Immersion when I pointed at element no 11 on their diagram. 47 minutes ago, Dan F said: Maybe, but they have a pretty strong recommendation regarding the need for 60C primary flow for use of the top coil. You might get away with 55C if you don't plan to heat tank to more than 48/50C, but Mixergy won't recommend that. I see what you mean. It may defeat the object in the first place. 48 minutes ago, Dan F said: Do you mean the WWHRS? Directly into the mixer. It's not the most efficient setup, but it's by far the easiest as showers don't need to be near the UVC. Yes, sorry, Zypho is just one of the brands. I guess the trouble with running back to the UVC is extra lengths of pipes, and possibly transfer heat losses? Link to comment Share on other sites More sharing options...
Kevm Posted January 22, 2022 Share Posted January 22, 2022 4 hours ago, BartW said: I suppose that is not bad. Have you done a cost-to-run chart to see what it is really costing you? Also, how big is the house? Yes, I've got lots of data. House is 160m2 but a 1990 bungalow not a new build. December 2021 was 25.5 kWh/day average. Link to comment Share on other sites More sharing options...
BartW Posted January 22, 2022 Author Share Posted January 22, 2022 1 hour ago, Kevm said: Yes, I've got lots of data. House is 160m2 but a 1990 bungalow not a new build. December 2021 was 25.5 kWh/day average. would you say it’s in line with what you expected? Assuming you had gas before, how does that compare? Link to comment Share on other sites More sharing options...
Kevm Posted January 23, 2022 Share Posted January 23, 2022 8 hours ago, BartW said: would you say it’s in line with what you expected? Assuming you had gas before, how does that compare? I had storage heaters before. It's much better and cheaper than these. I think gas would be cheaper but that wasn't available. It's about what I thought and in line with my heat flow calculations. I'm not looking forward to the next price rise though. Link to comment Share on other sites More sharing options...
SteamyTea Posted January 23, 2022 Share Posted January 23, 2022 14 minutes ago, Kevm said: I had storage heaters I still have. I like the reliability of them. 15 minutes ago, Kevm said: not looking forward to the next price rise This is my dilemma. Buying a small ASHP is not that expensive. Fitting it is as it will require major work around the house. I don't like to see exposed pipework and hate radiators. So comes down to a combination of skirting board emitters and plinth heaters I think. Then working out how to do the DHW. Link to comment Share on other sites More sharing options...
ReedRichards Posted January 23, 2022 Share Posted January 23, 2022 1 hour ago, SteamyTea said: I don't like to see exposed pipework and hate radiators. Surely a radiator looks no worse than a storage heater - which you already have? Link to comment Share on other sites More sharing options...
SteamyTea Posted January 23, 2022 Share Posted January 23, 2022 Just now, ReedRichards said: Surely a radiator looks no worse than a storage heater - which you already have? Yes, and I hate it. No point replacing something you dislike with something similar, and disliking that as well. Link to comment Share on other sites More sharing options...
ReedRichards Posted January 23, 2022 Share Posted January 23, 2022 (edited) Surely Underfloor Heating is the only best option if you don't like your heating to be visible or audible? Edited January 23, 2022 by ReedRichards Link to comment Share on other sites More sharing options...
SteamyTea Posted January 23, 2022 Share Posted January 23, 2022 1 minute ago, ReedRichards said: Surely Underfloor Heating is the only best option if you don't like your heating to be visible or audible? Yes it would be, but not worth the expense and hassle on a low value house. Being such a low user of power <4MWh last year, none of the options really stack up. But I would get a more controllable and comfortable house, which would be a selling point, though I am considering renting the place out as I am spending more time 'up country' helping to look after my Mother. What I have spend in filling the car over the last 4 months would have bought the ASHP. Link to comment Share on other sites More sharing options...
ReedRichards Posted January 23, 2022 Share Posted January 23, 2022 If you're not going to live in the house then the fact that you don't like the look of radiators should not be an issue. And skirting board and plinth heaters still require pipes to supply them which will be as visible as the pipes that supply a radiator. Link to comment Share on other sites More sharing options...
SteamyTea Posted January 23, 2022 Share Posted January 23, 2022 7 minutes ago, ReedRichards said: If you're not going to live in the house then the fact that you don't like the look of radiators should not be an issue. And skirting board and plinth heaters still require pipes to supply them which will be as visible as the pipes that supply a radiator. Not they way I can route them. Been pondering it for years and think I have found s relatively simple way to hide all the gubbins. Just need to fid a decent route for the power cable. Link to comment Share on other sites More sharing options...
ProDave Posted January 23, 2022 Share Posted January 23, 2022 19 hours ago, BartW said: higher max temp, ref: Legionella heat cycle If that is a major factor in your choice of unit, take a minute to think why. When I was doing my system I had much the same debate, and a learned forum member concluded that if you have treated mains water and if you have an unvented hot water tank, then there really is no risk of legionnaires as the water treatment plant will have eliminated any that might have been present and there is no way win an unvented tank for anything to enter. Hence I heat mu UVC to 48 degrees with the ASHP and the only time it gets any hotter is when there is surplus PV generation diverted to the immersion heater. Link to comment Share on other sites More sharing options...
ProDave Posted January 23, 2022 Share Posted January 23, 2022 14 hours ago, BartW said: Ouch, I bet that hurts. Bicester to Penzance is about 5 - 6hrs. Newcastle is 5 Horus north from here. Done both as single journeys. It was tiring to say the least... Lightweights. Try doing Oxford to Inverness in one journey towing a caravan. 1 Link to comment Share on other sites More sharing options...
SteamyTea Posted January 23, 2022 Share Posted January 23, 2022 3 minutes ago, ProDave said: Lightweights. Try doing Oxford to Inverness in one journey towing a caravan. Yes, that is a proper 520 miles. Did Weymouth to 60 miles north of Glasgow, then Newcastle and back to Weymouth, via head office in Thame in a day. That was a proper day trip. Link to comment Share on other sites More sharing options...
Jenki Posted January 23, 2022 Share Posted January 23, 2022 4 minutes ago, ProDave said: Lightweights. Try doing Oxford to Inverness in one journey towing a caravan. How long was this Journey? From Preston to our plot is around 8hrs 30 drive. With minimal comfort breaks (2hrs further on from Inverness) Link to comment Share on other sites More sharing options...
ProDave Posted January 23, 2022 Share Posted January 23, 2022 24 minutes ago, Jenki said: How long was this Journey? From Preston to our plot is around 8hrs 30 drive. With minimal comfort breaks (2hrs further on from Inverness) 11 hours towing the snail only stopping for fuel and comfort breaks. Link to comment Share on other sites More sharing options...
SteamyTea Posted January 23, 2022 Share Posted January 23, 2022 42 minutes ago, ProDave said: stopping for fuel If I potter along, I can go 700 miles on a tankful. Link to comment Share on other sites More sharing options...
joe90 Posted January 23, 2022 Share Posted January 23, 2022 19 minutes ago, SteamyTea said: If I potter along, I can go 700 miles on a tankful. Not with a caravan on the back ? Link to comment Share on other sites More sharing options...
SteamyTea Posted January 23, 2022 Share Posted January 23, 2022 18 minutes ago, joe90 said: Not with a caravan on the back ? If I had to tow a van again, I would make sure I find another one, and smash into it. I love seeing the A30 scattered with the remains of the Aldis or Avondale. 1 1 Link to comment Share on other sites More sharing options...
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