JohnnyC

Hello, Thanks for sharing this. I am considering doing something similar in my ground floor. Quick question about the battens. Did you use treated or untreated ones? Thanks in advance!

Thank you. I had not looked at turndown ratios, so it seems as if I have plenty of additional research to do. I don't think I need R290, but I read in other posts people commenting that they would go for R290 if they would have to pick a heap pump again because of the better efficiency in cold weather (could this be one of the reasons why Vaillant installations top the charts in heatpumpmonitor.org?) My SAP annual heating requirement is 15719.9 kWh. I won't need to heat up to 70C. My setup is: - UFH downstairs (~55 m^2) - still to be installed - it's an open plan, so I am aiming for 1 zone - UFH upstairs (~50 m^2) - my builder installed 4 zones before asking me, but I plan to use these as 1 zone. - 250L UVC So I am hoping to have a flow of 35C for the UFH and 50 for the DHW? I see that probably I should avoid the Samsung R290 because of the hot gas bypass if I am aiming to get higher efficiency. Thanks again!

Hi there, In case this is useful to anyone, after a few weeks, Samsung has confirmed that the SA will work with Samsung R290 heat pumps. I have decided to go down the UVC in the end sacrificing additional space. I couldn't justify the lower efficiency having to heat water to 65C for the SA. Thanks for the feedback.

Hi there, Just wondering what the OP finally did about this. I am in a similar situation. My installer is pushing for a Mitsubishi Ecodan 8.5kW (R32). They say that it is more reliable than competitors (especially Vaillant). But I am tempted to ask them to install a Samsung Mono Gen7 8kW (R290) that should come at ~1£k cheaper overall. Similar to the OP, HA integration would be useful. I have checked in here (https://heatpumpmonitor.org/) and neither of these models rank very highly in terms of efficiency (no Samsung Gen 7 on the charts as far as I can tell, so looking at Gen 6). Any reasons why I should pick one model over the other(s)? Thanks very much in advance!

Thank you all very much for the feedback. I have read most of the Sunamp threads in the forum, and I still believe that this is an ideal solution for me. Apologies, I should have introduced these in my first post. I'm renovating a 4-bed. Vitorian mid-terrace (ca. 1900) in west London. The setup that I have in mind is as follows: - UHF throughout the property (already installed) - No radiators (already removed) - No gas boiler (already removed) - DHW through a Sunamp 300 hp-SG(VT?) - Heat pump for whole-house heating and DHW (R290-based) I already have PV (5kWp) and batteries (15kWh). I am aiming to run the UFH at a flow temperature of 35C for a >4.5 COP, and the Sunamp (I'm not sure about COP, but I would expect this to be much better than 1) to provide all DHW needs. I do not want to have to use direct electricity to heat the Sunamp since it negates the COP gains of doing this through the heat pump. Hence I need an R290-based heat pump to achieve this since these can heat up to 75C. My installer suggested using a Samsung R32 heat pump, but this does require heating through the heating element because of the Sunamp configuration, which I won't do. So the original question was as to whether anyone would have successfully installed a Samsung R290 mono-block heat pump with a Sunamp hp-SG (or an xPlus with a SG-01 Optimino key). Samsung customer service also won't tell me because their support team only speak to engineers. Re UVC, I do not have any loft/outside available space. Also, I am keen to not have to do the annual service, pump changes, etc. Surely these will result in a higher cost over 10 years' time compared with the higher initial cost of the Sunamp? But please correct me if I'm wrong and I'll try and make space for the UVC. Thanks a lot again!

Hi there, Just wondering if anyone has tried pairing a Sunamp Thermino hp-SG (or xPlus) with a Samsung R290 heat pump and whether this worked. From the Sunamp manual, it would seem as if only R32-based Samsung heat pumps would be compatible/supported by Sunamp (either for hp-SG units or the new xPlus ones with the respective SG key). However, the installation manual for these configures them to set a cap on the hot water temperature at 50C and make the last increase in temperature through the Sunamp built-in heating element. Of course, this negates any COP benefits of getting the heat pump to heat the PCM. I've asked Sunamp and Samsung over X re support for R290-based units, but they don't seem to know themselves. I guess my alternative would be to use a Valiant heat pump, which my installer is not keen on. (I do not have space for UVC.) Thanks very much in advance!

Thanks very much for the reply. That's very helpful feedback. That's what I feared re first floor. For dMEV, do you mean to have these instead the dMVHRs but in the same locations? Without heat recovery, I'm concerned that I'm going to be unhappy letting all that energy go to waste. Do you have suggestions for other dMVHR units that I should look at? I have seen the BSK ZEPHYR and alike, and they are more silent, although I was not convinced that the 70 seconds on/off was something that was going to work in my case, and I assume that this won't solve the issue with ventilation on the first floor... In the meantime, I'll give it another go at seeing if I would be able to fit ducts for a centralised MVHR system since we are lifting the floorboards on the first floor anyway. Thanks again!

Hi everyone, I'm John. I've been reading the forum for a while, but this is my first post. We moved into our victorian mid-terrace house a couple of years ago and we are doing some renovations now (side return and loft conversion; floor plans below). As part of the renovation, we are doing some work that affects ventilation (category of measure according to Appr. Doc. F volume 1 of building regs): - Removing external chimney (major) - Insulating a suspended ground floor (major) - Replacing more than 30% of the total existing windows (major) - Installing internal wall insulation to less than 50% of the external wall area (minor) - Loft conversion (minor) This is likely to result in a significant decrease of the ventilation levels in the dwelling that I am hoping to address using dMVHRs. We do not have loft or ceiling/wall space left for a central MVHR system, I'm afraid. The kitchen will have an extractor fan for the cooker with air recirculation. At the moment I am considering installing the following dMVHR units: - Vent-Axia Tempra (9 l/s; 15 l/s boost; unbalanced) - loft bathroom - Vent-Axia Tempra (9 l/s; 15 l/s boost; unbalanced) - first floor bathroom - Vent-Axia Tempra (9 l/s; 15 l/s boost; unbalanced) - ground floor cloakroom - TBC (any suggestions for specific models?) (~20 l/s; 60 l/s boost; unbalanced) - open plan kitchen living area on ground floor These should satisfy building regulations' minimum ventilation levels for the whole dwelling in terms of: - minimum extraction ventilation for wet rooms - 4 rooms: 37 l/s - total area: ~42 l/s Since we are changing the windows, I am also installing background ventilators (trickle vents) as follows: - no trickle vents in loft bathroom - no trickle vents in first floor bathroom - no trickle vents in ground floor - no trickle vents in first floor front room - trickle vents in first floor middle room - trickle vents in first floor back room - trickle vents in loft bedroom (velux windows and Juliet balcony) I am trying to ensure that all rooms will have adequate ventilation. The windows towards the front of the house though have a particular shape that will benefit from not having trickle vents (this would be a real eyesore). So I would prefer to avoid installing these. It would be great to get feedback on what people think about this and whether I should be implementing other approaches to ensure a correct level of ventilation. In particular: 1. Is the dMVHR in the kitchen going to be enough to provide ventilation to the whole ground floor? 2. Do I need to add a trickle vent to the non-bay-window in the first-floor front room? If so, what equivalent area mm2? 3. Any other suggestions for things that I should be considering? Thanks very much in advance for the feedback. Cheers, John

Hello everyone - I'm John, and I am renovating our mid-terrace victorian house in London. I've been reading the forum as a guest for a while, but I am keen to get more active now and see what feedback we get for some of the implementations that we have in mind. Cheers, John