Jump to content

Luke1

Members
  • Posts

    35
  • Joined

  • Last visited

Recent Profile Visitors

The recent visitors block is disabled and is not being shown to other users.

Luke1's Achievements

Member

Member (3/5)

0

Reputation

  1. I had picked up on this a while back. Hence why I took an extract from the Nibe installer handbook. Given the fact that the book states a number of different standby states would suggest that the crankcase heater mode should not be the default standby mode that I have so far witnessed. I am unable to find out what preset temperatures and sensors are required for the system to enter standby mode, however you would have thought in these current warm conditions that the crankcase heater would possibly turn off? If it doesn't then perhaps Nibe providing standby consumption rates for modes other than crankcase heater mode is very misleading. The Nibe uses 0.72kWh per day in standby 'crankcase heater' mode, so whilst not as bad as other systems noted here, its still adds up to a significant sum over the course of a year based on current energy prices. (More than £60!)
  2. I've got a NIBE F2040 8kW model. I have a shelly 3M monitoring the power usage. It would appear that when not in use the system is using 0.03kW. According to the installer manual this would suggest that the crankcase heater is operational. I do not see any settings to disable this and wondered if anyone else had found anything? I would expect the system to either be in Thermostat-off mode, or standby mode as per below table.
  3. For reference I had a Shelly EM monitoring my Nibe F2040. When not in use the standby power required is 39W. This includes running the internal control unit, & display etc (Can't normally hear any circulation pumps running).
  4. Kerosene has only recently spiked to 88ppl because of what is going on in Russian and Ukraine. If you'd bought in early February you'd have paid around 60ppl. Lets hope the spike is just temporary, however I fear it may not be! https://www.boilerjuice.com/kerosene-prices/
  5. Could it also be that the system is compensating for a big change in your desired room temperature? Are you running the system in Weather Compensation mode and are you generally keeping the house at a steady temperature, minimising the use of any setback temperatures? UFH and especially ASHP benefit from longer run time and not in short bursts, but I'm sure you're already aware of this?
  6. Are the sensors fixed in the correct locations and wired to the correct terminals on the control panel? Not unheard of for installers to mix these up. Also could it be that inlet temperature is a sensor further down the line from the ASHP. Ie. just before it enters the UFH manifold?
  7. Are you sure this is true? The Nibe system works on degree minutes. In the settings there is an option to add additional heat (immersion) when the degree minutes exceed 700 or another defined number. I suspect other systems are similar, hence why so many people complain about running costs when they try to use an ASHP like a conventional boiler. I also note that the Nibe system will try and run the compressor until the degree minutes hit 0. If the system is started after a period of blocking then the flow temperature will continue to increase (reducing COP) until either the maximum flow / return temp is reached or it hits 0DM. It will then oscillate at the higher end of the flow temperatures until it reduces the DM to 0.
  8. I’m not sure the house has to be EPC C or better to claim RHI. You do however need an EPC that is less than 2 years old and does not recommend further cavity wall or loft insulation.
  9. Thats very interesting, my Nibe allows me to set a schedule which can increase the DHW to luxury for certain periods, likewise the heating can also be scheduled to move the setpoint up and down. I'm now also making much better use of night rate electricity to heat the DHW and put as much heat into the house over night as possible. (My night rate is over 2 separate periods hence the wild swing in flow temp) How do you determine an increase in number of people in the house, to increase DHW temp? Nice to see someone else using Home Assistant too. It can make some nice graphs to track use etc.
  10. Yes both sensors are installed. I assume the hot water charging sensor is half way up the tank however I haven’t actually looked at it. I think this is the sensor the system uses when the temperature falls past a set point to re heat the tank.
  11. I'll monitor it over the next few days. Perhaps I'll set the heating to be off so that it doesn't switch over and I can then get a better idea of the times just for DHW I'll upload some graphs to a new thread when I've done this.
  12. That's interesting, whats your thinking behind the charge pump speed? I notice that 30% is only during 'wait' mode whilst the heat pump itself is not running. I've currently left my DM at -60, it seems to cycle 20-30mins on and 30mins off during the day, which apparently seems reasonable. I currently have WC enabled and I also have a room thermometer connected. It reduces the calculated flow temperature as the room temperature increases. Even though its not recommended for UFH due to slow reaction times it does seem to be working ok at keeping a steady temperature with a low ish flow temp. Sorry Ecodan people this has gone off topic!
  13. Yes the SMO20 controller. I've fiddled with the priority and it is currently set at 90mins DHW and 30mins heating. Generally very happy with the unit and controller (It seems a lot more straightforward to adjust settings than some of the other systems people talk about on here). How long have you had your unit and is it performing as expected? Don't tend to see many reviews on them here.
  14. I have an 8kW Nibe with a 200l UVC. Looking at last nights log at an ambient temp of 5C: Charging circuit: 2:40 - 33C 4:00 - 41C The system then switches over to do heating for 30 mins and then switches back to DHW at 4:30 4:30 - 41C 6:15 - 48C The top of the tank is as follows: 2:40 - 42C 4:00 - 42C 6:15 - 48C In the summer it was much quicker to heat the tank. I'm just wondering whether I should give the DHW full priority over heating to save the changeover time during E7 hours. That said, the flow temp at night for heating is around 40C so it wouldn't have had to wait for long to switch over I suspect. It seems your ecodan is much quicker to heat the DHW, but then I guess it also depends on your ambient temp and the frequency your HP is working at. Mine seems to work at 66Hz. Its generally never got higher than 80Hz, expect for one occasion where it hit 110Hz however this may be an anomaly. So its either operating at 83% or 60% of peak?? Does anyone know where you can find the maximum frequency stats for heat pumps?
  15. Yes correct. If in the future I need more hot water then I'll increase the tank storage temperature. The ASHP should be able to do 55C or so. Hopefully I am still achieving a COP of around 2.5 with the ASHP. Only downside is the heating demand is not fulfilled whilst the DHW is being heated and it has to catch up in the morning. (Trying to time this so that this also happens in E7 hours is tricky)
×
×
  • Create New...