SteamyTea Posted January 15, 2021 Share Posted January 15, 2021 2 minutes ago, canalsiderenovation said: cheap rate between midnight and 4am. is that when you want your heating on? May be useful for charging an EV, just don't do to many miles. Link to comment Share on other sites More sharing options...
canalsiderenovation Posted January 15, 2021 Author Share Posted January 15, 2021 3 minutes ago, SteamyTea said: is that when you want your heating on? May be useful for charging an EV, just don't do to many miles. We want our heating on all the time! Their daily rate with Octopus is however more competitive than the cheapest rate we can get elsewhere (see my first post) and then the 5.00pkwh during those few hours that would help. We don't have an EV. Link to comment Share on other sites More sharing options...
joe90 Posted January 15, 2021 Share Posted January 15, 2021 34 minutes ago, canalsiderenovation said: We haven't got our external wall insulation yet Ah! That’s not going to help. (Do I remember a certain person using all the hot water in one go ?) Link to comment Share on other sites More sharing options...
AliG Posted January 15, 2021 Share Posted January 15, 2021 1 hour ago, canalsiderenovation said: Ah I've found something else now in the handover pack. These charts are very helpful. The efficiency of an ASHP falls with both the flow temperature and the outside temperature as you can see below. This is for an Ecodan ASHP but it will generally follow for any ASHP. You can see a COP of maybe 2.2 for 2C outside and 50C flow versus maybe 3.2 for 35C flow. This is why ASHPs often don't work well when retrofitted in poorly insulated houses. This drives the chart that shows the effect of flow temp on heating costs that you have been provided with. The interesting thing is that by setting the flow temp at 50C you are getting a higher RHI payment and a higher heating cost. However, there is nothing stopping you turning down the flow temp as long as it is still enough for the house to reach your target temperature. Looking at the room by room design, the system has been designed to be capable of providing 8594W of heat. This is a very large amount of heat for the size of house. You could easily turn the flow temperature down to 45C and once your EWI is in probably closer to 40C. This will reduce your heating bills but not your comfort. There would be a riot in my house if I turned the thermostat down to 19C, assuming you found 22C comfortable before I wouldn't be turning it down much. You can also see the impact of cold temperatures. The COP falls, so you need more heat when the ASHP is least efficient. But hopefully this will only be for a few weeks of the year when the temperature is as low as it has been. It will be much better at even modestly higher temperatures. Link to comment Share on other sites More sharing options...
Dave Jones Posted January 15, 2021 Share Posted January 15, 2021 get a gas combi pronto! Link to comment Share on other sites More sharing options...
joe90 Posted January 15, 2021 Share Posted January 15, 2021 1 minute ago, Dave Jones said: get a gas combi pronto! A bit difficult with no mains gas available (or do you mean LPG ?). Link to comment Share on other sites More sharing options...
canalsiderenovation Posted January 15, 2021 Author Share Posted January 15, 2021 53 minutes ago, joe90 said: Ah! That’s not going to help. (Do I remember a certain person using all the hot water in one go ?) Yes!! Link to comment Share on other sites More sharing options...
canalsiderenovation Posted January 15, 2021 Author Share Posted January 15, 2021 12 minutes ago, Dave Jones said: get a gas combi pronto! We can't get gas due to our location. Link to comment Share on other sites More sharing options...
canalsiderenovation Posted January 15, 2021 Author Share Posted January 15, 2021 14 minutes ago, AliG said: Looking at the room by room design, the system has been designed to be capable of providing 8594W of heat. This is a very large amount of heat for the size of house. You could easily turn the flow temperature down to 45C and once your EWI is in probably closer to 40C. This will reduce your heating bills but not your comfort. There would be a riot in my house if I turned the thermostat down to 19C, assuming you found 22C comfortable before I wouldn't be turning it down much. How do I turn down the flow temperature. Well we survived last year with no heating, I'm going to try 19 and see how we get on. 22 degrees was nice for us but I would have had it warmer so I'm not sure how we are going to find 19 degrees. Link to comment Share on other sites More sharing options...
AliG Posted January 15, 2021 Share Posted January 15, 2021 (edited) 17 minutes ago, Dave Jones said: get a gas combi pronto! Much as this cannot be done in this case. If you ignore environmental concerns, electricity is considerably more expensive than gas. On my tariff I am paying 2.14p per kWh for gas and 14.29p per kWh for electricity, so electricity is 6.6x the price of gas. Thus with an 85% efficient gas boiler and an average COP of 3.3 an ASHP would be around 70% more expensive for heating than gas. People are perhaps being sold ASHPs as a cheaper way to heat their homes. They are absolutely not cheaper than a gas boiler if you have mains gas available. However, you get a generous RHI payment for an ASHP and you save on putting a gas supply in and on having two standing charges. So this evens things out, especially the RHI which will make the ASHP cheaper for the first 7 years. Edited January 15, 2021 by AliG 2 Link to comment Share on other sites More sharing options...
ProDave Posted January 15, 2021 Share Posted January 15, 2021 33 minutes ago, canalsiderenovation said: How do I turn down the flow temperature. Well we survived last year with no heating, I'm going to try 19 and see how we get on. 22 degrees was nice for us but I would have had it warmer so I'm not sure how we are going to find 19 degrees. When I bought my first house, I was so poor (crippled with high interest rates) I had the heating on at 16 degrees. You get used to it. Link to comment Share on other sites More sharing options...
canalsiderenovation Posted January 15, 2021 Author Share Posted January 15, 2021 7 minutes ago, ProDave said: When I bought my first house, I was so poor (crippled with high interest rates) I had the heating on at 16 degrees. You get used to it. Exactly. In the three years we had the house before renovation we had heating for a month until it packed up and we survived with just the logo burner in the lounge albeit we moved the bed into the lounge. It was not pleasant. We are both nesh and I'm always complaining I am cold. Link to comment Share on other sites More sharing options...
joe90 Posted January 15, 2021 Share Posted January 15, 2021 1 hour ago, AliG said: People are perhaps being sold ASHPs as a cheaper way to heat their homes. Perhaps but people should do their homework 1 hour ago, AliG said: They are absolutely not cheaper than a gas boiler if you have mains gas available. But @canalsiderenovation don’t have gas 1 hour ago, AliG said: However, you get a generous RHI payment for an ASHP Only IF you pay an inflated price for having it fitted Link to comment Share on other sites More sharing options...
canalsiderenovation Posted January 15, 2021 Author Share Posted January 15, 2021 41 minutes ago, joe90 said: Perhaps but people should do their homework But @canalsiderenovation don’t have gas Only IF you pay an inflated price for having it fitted Yes we don't have gas and our ground was not suitable for GSHP so our options were limited unless we wanted to stay on oil. We did go down the RHI route and our payments will start in March. I just need to do some monitoring of the meters now and see what's happening. If anyone knows how to reduce the flow temperature then that would be great. Link to comment Share on other sites More sharing options...
AliG Posted January 15, 2021 Share Posted January 15, 2021 2 hours ago, canalsiderenovation said: How do I turn down the flow temperature. There is another thread discussing a Samsung ASHP where the owner has been told to reduce the flow temp https://forum.buildhub.org.uk/topic/14093-samsung-ashp-water-isnt-reaching-temp-goal/ I cannot find the user manual for the Samsung ASHP anywhere online, I found an installation manual. Maybe someone else with one can advise but usually there is a DHW temperature and a heating temperature set. The documentation says they are both set at 50C. Usually the heating temperature is lower. I would have thought your floors are getting pretty toasty at that flow temp. Link to comment Share on other sites More sharing options...
TonyT Posted January 15, 2021 Share Posted January 15, 2021 10 minutes ago, canalsiderenovation said: Yes we don't have gas and our ground was not suitable for GSHP so our options were limited unless we wanted to stay on oil. We did go down the RHI route and our payments will start in March. I just need to do some monitoring of the meters now and see what's happening. If anyone knows how to reduce the flow temperature then that would be great. You have a body of water next to you, there is a great thread on Navitron forum where Nowty uses a body of water under his house to run his Heat pump!! he had copper slinkies in the water. https://www.navitron.org.uk/forum/index.php/topic,29762.0.html Link to comment Share on other sites More sharing options...
canalsiderenovation Posted January 15, 2021 Author Share Posted January 15, 2021 40 minutes ago, TonyT said: You have a body of water next to you, there is a great thread on Navitron forum where Nowty uses a body of water under his house to run his Heat pump!! he had copper slinkies in the water. https://www.navitron.org.uk/forum/index.php/topic,29762.0.html Don't get me started! We did look at this as we have a good flow but it was a no goer - CRT. Link to comment Share on other sites More sharing options...
canalsiderenovation Posted January 15, 2021 Author Share Posted January 15, 2021 52 minutes ago, AliG said: There is another thread discussing a Samsung ASHP where the owner has been told to reduce the flow temp https://forum.buildhub.org.uk/topic/14093-samsung-ashp-water-isnt-reaching-temp-goal/ I cannot find the user manual for the Samsung ASHP anywhere online, I found an installation manual. Maybe someone else with one can advise but usually there is a DHW temperature and a heating temperature set. The documentation says they are both set at 50C. Usually the heating temperature is lower. I would have thought your floors are getting pretty toasty at that flow temp. Success but I can't see anything about flow temperature. Link to comment Share on other sites More sharing options...
canalsiderenovation Posted January 15, 2021 Author Share Posted January 15, 2021 Found an online version of the manual https://www.samsung.com/uk/support/model/MWR-WW10N/ If anyone has any suggestions that would be great. I tried to navigate but the only screen I could get to is this. Link to comment Share on other sites More sharing options...
ProDave Posted January 15, 2021 Share Posted January 15, 2021 Page 8 of the manual shows you how to adjust the "water outlet" temperature. 1 Link to comment Share on other sites More sharing options...
canalsiderenovation Posted January 15, 2021 Author Share Posted January 15, 2021 9 minutes ago, ProDave said: Page 8 of the manual shows you how to adjust the "water outlet" temperature. I'll have a play around now to see if I can change it. I think Alto have blocked off being able to make any changes/locked it. If I can get into it I'll reduce the temperature to about 45 degrees. Link to comment Share on other sites More sharing options...
canalsiderenovation Posted January 15, 2021 Author Share Posted January 15, 2021 Okey, this is a bit confusing. I can seem to get to the heat menu below. I can then adjust the temperature up or down (to minus figures) but I presume this is 0 as the room stats are controlling this. I've no idea what the temperatures are on the other side - is it those I need to change as I don't seem to be able to do that. Then there is the hot water settings which I presume I don't need to adjust? Link to comment Share on other sites More sharing options...
ProDave Posted January 15, 2021 Share Posted January 15, 2021 The water outlet temperature is the temperature that the heat pump will try and deliver when the heating is on. 48 is too high. The room thermostat then turns the heating on and off as needed. You want the water temperature as low as will work. If the rooms do not get hot enough it is too low. A bit of trial and error. 1 Link to comment Share on other sites More sharing options...
canalsiderenovation Posted January 15, 2021 Author Share Posted January 15, 2021 3 minutes ago, ProDave said: The water outlet temperature is the temperature that the heat pump will try and deliver when the heating is on. 48 is too high. The room thermostat then turns the heating on and off as needed. You want the water temperature as low as will work. If the rooms do not get hot enough it is too low. A bit of trial and error. Ok I'll adjust that to 45 and see how that goes now our thermostats are on 19 degrees! Thank you. It's going to be trial and error I think. I then need to look at electricity tarrifs as our fix is up end of Feb. Link to comment Share on other sites More sharing options...
AliG Posted January 15, 2021 Share Posted January 15, 2021 (edited) 48 looks to malice the DHW temperature which is OK. You can see it is hot water in the top left hand corner. However, Water Law seems to be Samsung's catchy name for weather compensation. This is switched on and it looks to me like your UFH flow temp is running at 56C currently (water outlet on the water law page). I am not sure how to switch it off and just set a flow temp. I tried reading the manual but it is not easy going. The Water Law setting that you have at 0 I think adjusts relative to whatever temperature the weather compensation has been programmed to give out. I believe from Google that this can be set between -5 and +5, but you can see what it will let you set. Thus if you set it to -5C then your flow temp should drop by 5C. Reading the manual it would be quite involved to change the weather compensation settings. It looks to me like they have been set with a very high flow temperature when it is cold outside as at the moment. There are options to set a range of outside temperatures and then a range of flow temperatures dependent on this variable. You can see them on p27, the unit seems to have been set somewhat higher than the default temperatures. Edited January 15, 2021 by AliG 1 Link to comment Share on other sites More sharing options...
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