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Heat Pump Running Costs

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  • Registered Users Posts: 781 ✭✭✭staples7


    100% you’ll only do it once. Mines A2 but I often wonder is it.

    what do you reckon your cost is for those 5.5kwh? I reckon I’m about the €2 a day. Have .14c night rate



  • Registered Users Posts: 867 ✭✭✭ColemanY2K


    may i ask what your ACH score was? i did the same wrt airtightness and was aiming for passive (0.6) but unfortunately ended with a reading of 1.8 ACH. i know the general area where most of the leaks are so will go and tackle them before I get the guy back to do a final air tightness test.

    by the way, under 6kWh / day is mightily impressive.

    🌞 7.79kWp PV System. Comprised of 4.92kWp Tilting Ground Mount + 2.87kWp @ 27°, azimuth 180°, West Waterford 🌞



  • Registered Users Posts: 860 ✭✭✭keno-daytrader



    Im on the flogas 29 cent 24h community plan, so 1.6 a day for Nov, so your doing really well at 2euros/day on that night rate.

    Are you still building? If so still room to improve that score, but 1.8 is a good test. Our house got 1.1, we built a dormer so was pleased with that result, as dormers can be challenging for airtightness.

    ☀️ 6.72kWp ⚡2.52kWp south, ⚡4.20kWp west



  • Registered Users Posts: 19,898 ✭✭✭✭Cyrus


    Folks if you are getting a shelly does it get wired into everything on your consumer unit or how does it work, id be interested in some monitoring like this and ill get my sparks to do it, but what do i need?



  • Registered Users Posts: 867 ✭✭✭ColemanY2K


    1.1 is a very good result. Jesus I'd be over the moon if the HP ends using 5.5kW per day.

    My own house is nearly finished, tbh if it wasn't for the plumber arsing around we'd be in by now.

    It's a 2100sqft bungalow and most of the leaks are in the membrane fixed to the joists so it's a case of going up into the attic and sealing the leaks. I bought myself a smoke pencil and have a thermal camera to help identify the leaks so I'll spend a few evenings over the next few weeks sealing the holes. After the test I'll lay the mineral wool insulation and that will be that.

    🌞 7.79kWp PV System. Comprised of 4.92kWp Tilting Ground Mount + 2.87kWp @ 27°, azimuth 180°, West Waterford 🌞



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  • Registered Users Posts: 354 ✭✭munsterfan2


    Running at just under 10kw per day, 2500 sq ft




  • Registered Users Posts: 781 ✭✭✭staples7


    ya a whisker under 10kwh average so far in Nov. 2022 was about 9kwh for same period. 2021 was 8kwh.

    looked back to dec last year and it’s about 18kwh. Outside temp was close to zero for much of that spell.

    again all down to weather





  • Registered Users Posts: 161 ✭✭johndoe11


    God I'd love to getting those numbers, you must all live near the coast! I'm in the Midlands and the last few days have used around 25 kwh a day, been very close to 0 at night and not much above 6/7 during the day. It a IVT AirX installed since 2017. The house 2700sq ft and is A1, it was A2 before solar panels. I run it slightly higher temperature at night so most units are night rate.



  • Registered Users Posts: 2,486 ✭✭✭ECO_Mental


    Here is my moving 7 day average of my Joule/Samsung A2W heat pump. I live in a 220ms A1 (A2 without solar) house. Currently average about 17 kWh day but has gone up to 20. As you can see last December when we had that really cold snap for two weeks my HP was working over time and went up to over 40 kWH/day....but some of those days it didn't get about freezing even during the day and it went down to -5 to nearly -10 if I am not mistaken.

    4 adults in the house and someone is working from home all the time, my young adults 18-20 love to have 20-30 minute showers (at least once a day..) 🙄 so that drives a good bit of my energy use.


    6.1kWp south facing, South of Cork City



  • Registered Users Posts: 19,898 ✭✭✭✭Cyrus




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  • Registered Users Posts: 2,486 ✭✭✭ECO_Mental


    @Cyrus Home Assistant (HA) on a Raspberry Pi4b, I use a couple of ShellyEMs in my consumer board to log the key circuits in my house (HP, Solar PV, Zappi, Utility room and ESB Incomer)

    The data is stored using InfluxDB and the graphs are using Grafana, all sounds a bit complicated but I'm no computer programmer but you need be be somewhat tech savvy that's all.

    In HA you can also has other dash boards that are more simple and has a mobile app that is very useful that you can check easily on the fly


    6.1kWp south facing, South of Cork City



  • Registered Users Posts: 19,898 ✭✭✭✭Cyrus


    Thank you, I use HA already so I’m sure I can figure it out.

    how many Shelly’s do you need and how many circuits are you monitoring? Do you just do overall and HP?



  • Registered Users Posts: 2,486 ✭✭✭ECO_Mental


    I log 6 circuits...I initially got one just to log my main incomer and my PV to see what I was exporting/importing and what my PV was generating (the Solis app was crap and was only every 5 mins) I then realised I need to be logging my HP to really manage it so I ordered another Shelly to do that and the utility room..but! as it happens Shelly sent me an extra one my mistake so I ended up with three ShellyEM so I can log 6 circuits.

    Main ESB Incomer, Solar PV, Heat Pump, Zappi, Utility Room and the kitchen Island. The middle graph in my previous post is all 6 circuits and is the power usage over the last 24 hours.

    If you have an all electric house like me it essential that you have a live monitor that you can check instantly if something is on or not so you can pin down whats using your energy.


    6.1kWp south facing, South of Cork City



  • Registered Users Posts: 432 ✭✭jasgrif11


    @ECO_Mental thanks for sharing. I use a lot of Shellys. I really like them. Right now I have simple dat capture in HA. I must look into Grafana. Have you come across any howto guides?




  • Registered Users Posts: 2,486 ✭✭✭ECO_Mental


    the auld youtube is your friend here, cant remember who i looked at setting up InfluxDB and Grafanna but this dude always puts out good tutorials about HA. Here he is setting up InfluxDB and Grafanna

    NEXT LEVEL STATISTICS - Home Assistant InfluxDB and Grafana - YouTube

    6.1kWp south facing, South of Cork City



  • Moderators, Home & Garden Moderators Posts: 5,912 Mod ✭✭✭✭graememk


    With the circulation pump running on mine, I'm measuring 45w idle, Circ pump is running due to low temperatures outside.



  • Registered Users Posts: 241 ✭✭Dutch Roll


    @jasgrif11 can I ask how are you powering your Shellys?

    I have no room in my consumer unit. Can they be wired to a 3pin plug and plugged into a spare socket?



  • Registered Users Posts: 432 ✭✭jasgrif11


    Yes they can be wired to a 3 pin plug. I combined mine with an existing RCB in my consumer unit. I have one for main electrical and another on my Heatpump. Separately I have them connected directly to my dishwasher, dryer and washing machine (where the shelly is in the socket)



  • Registered Users Posts: 19,898 ✭✭✭✭Cyrus




  • Registered Users Posts: 432 ✭✭jasgrif11


    No, not at all. What I did was purchase a double socket and deeper surface mount box. This gave me loads of room to add in the Shelly. The result is this:




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  • Registered Users Posts: 2,868 ✭✭✭dominatinMC


    With the current cold snap, how are peoples HPs coping now? My usage has shot up, with yesterdays usage being 22kWh. Before the cold spell, I was in around 12-14 kWh per day for the month of Nov. Will put up data shortly.



  • Registered Users Posts: 781 ✭✭✭staples7


    Similar, I was ticking away at 8-10kwh inc hot water. At about 20kwh for last 4/5 days. It does help that’s all at 14c per kWh hour on night rate.



  • Moderators, Home & Garden Moderators Posts: 5,912 Mod ✭✭✭✭graememk


    First days proper stats once i got all my recording working correctly

    28kwh electric, 78kwh heat out. Ecoforest, Running at a 50C temperature during the day, and going to 60 overnight, taking advantage of the cheaper night rate. Taking a hit on the COP though. All from night rate or batteries. I am running a large buffer acting as a battery too.

    1980's house, was a c2 after solar but would have hit a b3 if my oil boiler wasnt 30+ yrs old at the time.



  • Registered Users Posts: 1,423 ✭✭✭DC999


    You upgrade or add any rads or left the existing ones there running at 50C?



  • Moderators, Home & Garden Moderators Posts: 5,912 Mod ✭✭✭✭graememk


    Left them be, Was running at that for the last year from the buffer tank anyway( link). A lot of them already are double rads at this stage anyway.

    Living room (4m*5m, Stove) is struggling a bit, 2 external walls and 2 big windows. 1400mm rad. Radiator is also behind sofa. Have ordered some radiator fans as an experiment, to assist the air flow. Can get to 20c fine, but to get above 20 is harder. Flow temps vary from 50-45 as HP doesn't kick in again until its 5c under the buffer setpoint. Never was an issue as there's always been a fire on before this.

    Have a small fire on these nights, but its not like how it used to be. (like firing a steam engine on these cold days!)

    Interesting how I ball parked 100kwh a day (of heat) last year. which possibly would be on point for the cold days.

    I suppose i'm only running at a deltaT (difference between room temp and rad temp) of 30c too, Looking at similarish radiators, its about 1kw at that delta.

    Looking at steelrad to convert all the delta50 to delta30 you multiply by 0.515. So If I was able to go for a 2m radiator in there, (I have the space Possibly just extend the pipes out) It would boost the output by 800ish watts.



  • Registered Users Posts: 1,720 ✭✭✭poker--addict


    Hi graememk for clarity I don't have a2a, anecdotally I understand the efficiency is the same or better than a2w, albeit a2w and UfH is a different mindset of slow hear up of a slab etc - a2a is going to be more fast up/fast down.

    My old Ground source ran around 90kw yesterday- I'm starting to think a2a can't be any worse but gives me cool air in summer

    😎



  • Moderators, Home & Garden Moderators Posts: 5,912 Mod ✭✭✭✭graememk


    I meant your efficiency for your ground source. Do you know the kWh out?

    A2W or ground source will easily beat air source if installed correctly. With underfloor you should be able to hit 4-500% efficiency due to low flow temperatures.



  • Registered Users Posts: 2,486 ✭✭✭ECO_Mental


    The cold weather over the last few days has shot me right up..hovering around 28 kWh/day now..this is including DHW as well


    6.1kWp south facing, South of Cork City



  • Registered Users Posts: 1,720 ✭✭✭poker--addict


    I estimate its about 2.8-3 last time I tried to assess it (do not have a KW out reading - and are they accurate anyway?). It was poorly designed I suspect. there are manifolds up and downstairs, with circ pumps each around 150-200watts/hour (connected to room thermostats not Heat pump, so calling all day). that is nearly 8kw per day before the pump even fires - and then its old, so not inverter, so around 4.5KW/hour when it fires. A new system would likely have no circ pumps outside the Heat pump, and heat pump would run constantly at a lower KW instead of cycling on and off (as i understand it)

    😎



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  • Administrators Posts: 357 Admin ✭✭✭✭✭System


    This discussion was created from comments split from: Air to Air with hot water systems.


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