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New Build, 7 months in with a Danfoss heatpump

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    #62
    Charlie Charolais
    Registered Users Posts: 263 ✭✭Charlie Charolais


    KCross wrote: »
    @BarneyMc, do you have a meter attached to your HeatPump and know exactly what it is costing you per year? Care to share? Also, what size house is it?

    we have an A2W going since 24th jan, we fitted a dual tariff meter on the decided HP power supply, i will keep you informed & hopefully myself sane!


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    #63
    daphne
    Registered Users Posts: 65 ✭✭daphne


    I'm a bit concerned about the relative large envelope we have - narrow plan. Will need all the insulation we have I think. The whole thing is a bit of a leap - you just hope that you've got enough insulation and the bills won't be nuts.  I'd say you'd be advised to fire on your stoves in very cold weather to do some of the heavy lifting.  We will have to wait a good while to judge on what it's costing us as hope to move in summer...


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    #64
    matrat
    Registered Users Posts: 152 ✭✭matrat


    daphne wrote: »
    I'm a bit concerned about the relative large envelope we have - narrow plan. Will need all the insulation we have I think. The whole thing is a bit of a leap - you just hope that you've got enough insulation and the bills won't be nuts.  I'd say you'd be advised to fire on your stoves in very cold weather to do some of the heavy lifting.  We will have to wait a good while to judge on what it's costing us as hope to move in summer...

    Hi Daphne,

    Without knowing spec, sizes etc. i couldnt comment on that but i felt that with our restricted structure make up we may need a supplemental heat source to keep us comfortable in winter. Truth it that with the system constantly monitoring and adjusting input based on temps inside and out, it never gets to a stage when u culd light a stove. We are now 99% sure we will fit an electric stove to fill the gap, purely for aesthetic reasons. No doubt if u had the system on a time clock to not run during day for example, then yes the stove would provide quicker heat to the communal areas in the evening time while the system comes up to temp over the whole house. But as partially discussed before, it is not been proven that using the machine this way is more cost effective, and the cost associated with buying the stove, connecting air supply etc would pay for alot of esb to power the machine that has to be offset for it to be a value proposition. Again without knowing spec etc. i can only advise on my experience, but for me, paying for chimney flues, the construction of the chimney, chimney pot, guard for the top, flashings, ductwork in floor for air supply etc. was a waste of money. I could have built a dummy brace and slotted in the electric stove and would have been a fraction of the cost. Maybe a tenth of the cost, and that would be a generous electric stove. Put it another way, if in stalled a stove, given the true cost before i light it a single day, it would cost me around 6 years of esb on the HP. Maybe more.


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    #65
    Water John
    Registered Users Posts: 21,144 ✭✭✭✭Water John


    It is the sealed envelope, as much as the insulation.


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    #66
    daphne
    Registered Users Posts: 65 ✭✭daphne


    Another comforting comment Matrat! I was hoping the stoves would be visual features as opposed to absolutely needing them to heat the place. Hopefully we'll be the same as you.
    @Water John, we have air tightness detailing - taping at doors and windows, scratch coat inside, membrane in 1st floor ceiling and we're pushing for 1 ACH which may end up 0.5  higher but at least a good bit better than 3. MHRV installed...


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    #67
    matrat
    Registered Users Posts: 152 ✭✭matrat


    Happy to have some input daphne, hopefully it all works out for you.

    Something i keep trying to remind myself is that ok i could have built for cheaper, but realistically 800 euro for all heat and hot water per year is pretty dam good to me. Is impossible to compare to anything i have ever lived with before. Wake up at 5am to go to bathroom, no running over cold tiles or jumping from mat to carpet to keep feet warm. Sure it may be overkill to have the heat on 24/7 when it not always required, but i would be happy to be paying 800 euro to have it only when i needed it. The rest is a bonus!! Came from a 7 year old townhouse about half the size with electric shower, gas, a stove and immersion and the difference is shocking. Did up some bills there recently to compare and it is crazy. The heat here is so comfortable and relaxing and the MHRV keeps the house so fresh and airy ha. Smells dont linger, windows dont steam, its all good.

    In a stranger turn of events, when i started tracking the heat pump usage, i very stupidly didnt start and record the esb for the whole house. So have gotten several esb bills that always seemed low but been low, i didnt question ha. Now after reading the unit for the first time in 6 cycles i think, they have noticed the difference. So got a nice whack of a bill. Nothing ludicrous and spent some time yesterday just validating that makes sense and all does. They simply just estimated too low. But amazingly, somehow since the bill is large, 460 euro, then i divide the bill by the units charges, im only paying 15.6c per unit as opposed to 18.9c ha. I guess its a rounding issue and the larger count of units has watered down the standing charge and levy but overall happy ha. So have updated my excel file and from tomorrow on i will be recording both HP hours and esb units to house so i can get a baseline of how many units the house uses. For example, over Nov & Dec, the HP was on average using 21 units a day, the esb bill for the same period shows an average daily consumption for WHOLE HOUSE of 18 units.


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    #68
    Water John
    Registered Users Posts: 21,144 ✭✭✭✭Water John


    Ah, I'd say -3 units is enough to cook your dinner.


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    #69
    BarneyMc
    Registered Users Posts: 1,504 ✭✭✭BarneyMc


    KCross wrote: »
    @BarneyMc, do you have a meter attached to your HeatPump and know exactly what it is costing you per year? Care to share? Also, what size house is it?

    Unfortunately not. No meter but would like to get one. Also, just paid an electric bill but we only moved in Dec 23rd and only submitted a meter reading the other day. My next bill will give me some indication.

    My house is 2800 sq feet, 250mm pumped cavity, 160mm PIR insulation in the ground floor, 400mm mineral wool in the attic.

    I'm sort of cooking the books regarding the HP. I'm on a dual tariff so only let the HP run at night. The house stays warm the whole day so no need to run it during the day at all. No idea what I'm saving but I'm sure it must be something.

    Anyway I think you can get too carried away with costs, etc. When you get to a certain point, going the extra mile may not be worth it. I'm so happy with the house and how even a temp there is throughout. Also the fresh air with the HRV system is super. It's such a pity to see houses built to 'ach sure it will do' standards.


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    #70
    faulty
    Registered Users Posts: 10 ✭faulty


    Hi,
    This thread is super, some great and helpful information on it. I have just started a self build, the builder/project manager is doing the full job. We are installing a Danfoss A2W heatpump for UFH heating on both floors within a 2400 sq ft house.

    Would anyone have a good estimate of the cost of the Danfoss heatpump. We are getting the Danfoss DHQ-AP 11Kw installed. Danfoss was recommended to me as possibly more expensive but best A2W heat pump on the market.
    What would be the break down of the Heat Pump and associated Maxi unit?
    UFH costs?
    Installation costs?

    This is a PC some on our building quote, but need to know the expected cost for our budget.

    Any help would be great appreciated, thanks.
    Faulty.

    PM if necessary


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    #71
    Water John
    Registered Users Posts: 21,144 ✭✭✭✭Water John


    PM sent.


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    #72
    tobdom
    Registered Users Posts: 510 ✭✭✭tobdom


    Water John wrote: »
    PM sent.

    Would you mind at all PM'ing me the same info as we're currently exploring this ourselves for a new self-build.

    Thanks in advance!


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    #73
    murphaph
    Registered Users Posts: 19,018 ✭✭✭✭murphaph


    faulty wrote: »
    Hi,
    This thread is super, some great and helpful information on it. I have just started a self build, the builder/project manager is doing the full job. We are installing a Danfoss A2W heatpump for UFH heating on both floors within a 2400 sq ft house.

    Would anyone have a good estimate of the cost of the Danfoss heatpump. We are getting the Danfoss DHQ-AP 11Kw installed. Danfoss was recommended to me as possibly more expensive but best A2W heat pump on the market.
    What would be the break down of the Heat Pump and associated Maxi unit?
    UFH costs?
    Installation costs?

    This is a PC some on our building quote, but need to know the expected cost for our budget.

    Any help would be great appreciated, thanks.
    Faulty.

    PM if necessary
    We have the equivalent of that model from Thermia (same innards, just different branding) and I think they are solid machines but no longer state of the art (assuming this machine has not been updated-I didn't look to closely at it). They do not modulate to exactly match the instantaneous heat demand of the building. Maybe consider a modulating heat pump or at least read up on them before making your decision.

    I honestly think that given the fairly poor energy demand calculations that a generally done with Irish builds, a modulating heat pump is a much safer bet as an over-sized heat pump that doesn't modulate will cycle often and this causes premature failure of the compressor as well as being inefficient due to more start ups (even with soft start it takes more energy to get a compressor to start running than to keep it running).

    I can't help you with the costs as we built in Germany.


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    #74
    matrat
    Registered Users Posts: 152 ✭✭matrat


    faulty wrote: »
    Hi,
    This thread is super, some great and helpful information on it. I have just started a self build, the builder/project manager is doing the full job. We are installing a Danfoss A2W heatpump for UFH heating on both floors within a 2400 sq ft house.

    Would anyone have a good estimate of the cost of the Danfoss heatpump. We are getting the Danfoss DHQ-AP 11Kw installed. Danfoss was recommended to me as possibly more expensive but best A2W heat pump on the market.
    What would be the break down of the Heat Pump and associated Maxi unit?
    UFH costs?
    Installation costs?

    This is a PC some on our building quote, but need to know the expected cost for our budget.

    Any help would be great appreciated, thanks.
    Faulty.

    PM if necessary

    Hi Faulty,

    I think the best thing to do would be to contact some suppliers/installers for prices etc. I believe Heat Pumps Ireland are the main Danfoss Rep in the country and most independent installers machines come through them.

    I can provide you with my costs;
    UFH for 2950 sq foot: most prices came in around the same range, in the region of 5.5K for supply and install. With you smaller footprint, unless very complex layout, i would assume u culd knock about 15% off that.
    HP: My 8kw HP was i think around 9K. This is a Geo unit with integrated hot water tank so not sure how relevant that price is to you.
    Installation costs: This figured moved around but is in the region of 2.5k it ended up. That includes all materials, connections to borehole etc.

    One thing i would suggest is to contact a few installers/suppliers for getting a good understanding or a baseline idea of the system from multiple parties. I found i had quotes for 8 - 16kw systems. My calculations showed around 8kw so i was happy and am very happy now that i didnt fork out for a machine that is too large, which apparently often cost more to run and lead to premature failures due to start/stopping.


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    #75
    Ray Donovan
    Registered Users Posts: 1,015 ✭✭✭Ray Donovan


    I've just turned on my IVT Airx 90 for the first time one hour ago!!!! Very exciting. Currently pulling around 9 kwh which equates to about €1,000 per month on electricity!!


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    #76
    gooner99
    Registered Users Posts: 2,040 ✭✭✭gooner99


    Ray Donovan wrote: »
    I've just turned on my IVT Airx 90 for the first time one hour ago!!!! Very exciting. Currently pulling around 9 kwh which equates to about €1,000 per month on electricity!!

    How is it going tonight. Still pulling the same kwh?

    Coukd be the house drying out.


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    #77
    gooner99
    Registered Users Posts: 2,040 ✭✭✭gooner99


    Ray Donovan wrote: »
    I've just turned on my IVT Airx 90 for the first time one hour ago!!!! Very exciting. Currently pulling around 9 kwh which equates to about €1,000 per month on electricity!!

    How is it going tonight. Still pulling the same kwh?

    Coukd be the house drying out.


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    #78
    Ray Donovan
    Registered Users Posts: 1,015 ✭✭✭Ray Donovan


    gooner99 wrote: »
    How is it going tonight. Still pulling the same kwh?

    Coukd be the house drying out.

    Ya house is drying out for the next couple of weeks.

    Currently pulling 4kwh over the last 15 hours by my calculations.


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    #79
    Ray Donovan
    Registered Users Posts: 1,015 ✭✭✭Ray Donovan


    From Friday 8pm until tonight (5 days) the pump according to the digital display has used just over 200kwh which by my calculations is 2.25kw per hour. The house is drying out really well thankfully.


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    #80
    CaraK
    Registered Users Posts: 69 ✭✭CaraK


    matrat wrote: »
    Hi zulutango,

    1:My site is covered in old trees so the idea of having to dig that up to lay pipework was never that appealing. Given that vertical borehole are proven to be more efficient and the cost to dig around trees etc, we went with borehole. Was 3850e. The supply, fitting and commission of heatpump and underfloor was 16.5k.
    The quotes i got for an oil boiler, oil tank, boiler stove, stove box, all associated rads, pumps, valves etc. all supplied and fitted with first fill of oil was around 15k.

    2: Yes, underfloor to whole house. It is essential for this type of system. I labored to the installer for two days to do the whole house. A simple process. I would imagine for the small amount of euros people save by using alu rads upstairs only for example, would be offset by the higher running costs or more unstable temps.

    3: No problem. As i was the first new house the insulation installer completed with the cavity insulation, part of the deal was that the house would be air pressure tested (at his expense) before final payment to confirm its results. The magic number agreed upon was 3m3/hm2 which i thought was ambitious ha. The test was done with no internal plaster or floor, no tape on windows, a big sponge up the chimney, and a few crudely placed pieces of plastic under external doors. The result came in at 5.1 which i was quietly impressed with given the level of "sealing" at the above areas. We shook hands on me buying the materials to tape all windows and doors out of final payment and i did the work myself. As to what it is at now after tape, plaster, floors etc. i would guess maybe 3 but really have no idea. I am happy enough it is to the level that i am getting good use and need for the mhrv so i am happy enough. And given the fact we see literally no bugs in the house i am assuming it is fairly well sealed.

    Did you do blower door test after sealing everything up

    Can you pm your heat pump installers details please


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    #81
    matrat
    Registered Users Posts: 152 ✭✭matrat


    Hi CaraK, 

    Yeah we did a blower test but was not at a typical time. In a regular build i would be doing a blower test once you feel you are satisfied that your airtight layer is complete and then use the test to validate and/or identify any issue areas remaining. We did our test as a validation of a new insulation that the installer had not used before so it was on my request to validate his claims. And the tester was arranged by him. I had met him before at a home exhibition so i agreed to using him. He had good kit but he knew as much about what we where looking for as i do about the man on the moon. I would not have paid him but wasnt my cost so wasnt an issue. I was there for the whole process and having some experience with testing before i basically took control of the machine and the test. The insulation installer had made some very ambitious claims about how airtight his insulation would make it so i let him back himself into a corner and held him to it. 
    I will send you a PM now


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    #82
    BarneyMc
    Registered Users Posts: 1,504 ✭✭✭BarneyMc


    I run an A2W HP and use the dual tariff setup. My dual tariff electricity contract has just expired and am considering new suppliers. The best deal I can get is 14.19 cent per unit day rate and 7.03 cent per unit night rate (there is a slightly better deal available but I can use my rewards points with this one).

    Should I consider dropping the dual tariff altogether and go for standard tariff? Only in the house since Christmas so can't really say how it's working out cost wise. Anyway would be good to see what tariff other A2W HP owners use.


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    #83
    BarneyMc
    Registered Users Posts: 1,504 ✭✭✭BarneyMc


    OK just off the phone... it costs €195 to switch meters... I'll be sticking to the dual tariff!


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    #84
    KCross
    Registered Users Posts: 12,077 ✭✭✭✭KCross


    BarneyMc wrote: »
    I run an A2W HP and use the dual tariff setup. My dual tariff electricity contract has just expired and am considering new suppliers. The best deal I can get is 14.19 cent per unit day rate and 7.03 cent per unit night rate (there is a slightly better deal available but I can use my rewards points with this one).

    Should I consider dropping the dual tariff altogether and go for standard tariff? Only in the house since Christmas so can't really say how it's working out cost wise. Anyway would be good to see what tariff other A2W HP owners use.

    I dont get it. Why would you switch back?

    Everyone using a HP should have a dual tariff meter. If you use ~3kWh by night it pays for itself. Having a HP and some appliances running at night will well exceed 3kWh.


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    #85
    faulty
    Registered Users Posts: 10 ✭faulty


    In relation to the Danfoss HP. The Danfoss DHP-AQ 11kw with Maxi control unit has been recommended to me. In relation to the control unit, is the hot water cylinder within the control unit or is it separate? Eg will be placed in the Hotpress as the Maxi control unit is going to be located in the utility room.

    Has anyone used the Danfoss DHP-AQ Maxi unit?

    Cheers!


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    #86
    Shaunoc
    Registered Users Posts: 521 ✭✭✭Shaunoc


    180 litre cylinder is within unit in our utility. Meaning we have an upstairs 'hotpress' area for extra storage


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    #87
    faulty
    Registered Users Posts: 10 ✭faulty


    Shaunoc wrote: »
    180 litre cylinder is within unit in our utility. Meaning we have an upstairs 'hotpress' area for extra storage

    Great, that is what I was thinking, no need for a cylinder upstairs.
    And you are happy with it, you always have enough hot water.


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    #88
    Shaunoc
    Registered Users Posts: 521 ✭✭✭Shaunoc


    Just 2 in our household so its capacity is not being tested. So far I'm happy, always hot water for shower and sinks.

    If you check for average litres used you may find figures of 62 litres for average shower. Chances of 3 showers at same time or very close together..may dictate your decision. For me its not a concern.

    As tank is in our utility it takes extra seconds for hot water to reach upstairs taps. That annoys my wife.


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    #89
    murphaph
    Registered Users Posts: 19,018 ✭✭✭✭murphaph


    We're a family of 3 and have also never run out of hot water with the 180l tank.

    You should always try to size the tank just slightly larger than needed because you have to drive it up to almost 70°C once a week to kill legionella and the smaller the tank the less this costs obviously.

    Easier said than done as families grow and contract as kids move out but something to bear in mind when someone suggests just bunging in the biggest tank you can fit (I know families of 3 with 500l tanks they never come near maxing out).


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    #90
    faulty
    Registered Users Posts: 10 ✭faulty


    Hey,

    Thanks for the information above, its a great help.

    Faulty


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    #91
    JohnnyB23
    Registered Users Posts: 37 ✭JohnnyB23


    Ray Donovan wrote:
    I did some outrageous tossing and turning on how to heat it but eventually settled on A2W pump and HRV system. Engineer did up all sorts of costs analysis for me and it seemed the way to go. I also have 2 external air supply stoves going in but hopefully they'll be more for aesthetics!! The pump will be installed in the next month.

    Hi Ray, Any chance you could PM me supplier/installer details and cost of A2W pump and HRV system. What way did the last few months go for you regarding running costs?


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