Daikin hybrid air source heat pump system under green home energy grant

Discussion in 'Eco Talk' started by Caretaker29781, Jul 1, 2021.

  1. Hi Guys
    Is this a good system Daikin hybrid air source heat pump , as they will replace existing combi boiler to this renewable energy.
    This will do hot water and heating.
    It will be done through green homes energy grant.
    I don’t know how the running cost will be until it is fitted and used on the Victorian property.4 bedrooms, 3 living rooms, kitchen and 2 bathrooms and 16 Radiators.

    I don’t know service cost.

    So I wanted to know if someone has installed this and how effective is this system and do you save money on energy bill.

    Is this better system than solar panels, as solar panel only does hot water.

    Appreciated your replies and advice before they install.

    Many Thanks
     

    Attached Files:

  2. AnotherTopJob

    AnotherTopJob Screwfix Select

    Not sure about the specific system but unless your house is incredibly well insulated, the low level of heat compared to a normal boiler is unlikely to be adequate.
     
  3. jonathanc

    jonathanc Guest

    Surely you should be asking the installer for this info?

    tbh is bad practice to be posting personal information and commercially sensitive info such as the quotation in open forum…
     
  4. I asked the DAIKIN company nobody rang and the thing is you dont know when you use the hybrid system , as each property, location, users this is takes into account. i had a combi boiler and now it will get replaced with the Hybrid system and i wanted to see if anyone had a installation done and seen any difference in bills.

    I jsut removed my sister personal information, so i just left the quote.

    How do i remove the personal information, as once loaded up, you can not remove it.
     
  5. Muzungu

    Muzungu Screwfix Select

    So am I right in thinking with this system they are supplying both an air source heat pump for central heating only and then a combi boiler as well just for the hot water? So for, say, 5 months of the year you will make little or no theoretical savings at all as you will still be using a gas combi for hot water as you were before, and in winter are relying on the air source heat pump in addition to heat the house?

    Victorian property and keeping existing radiators with no underfloor heating I can't see any savings and whether you will be warm enough only time will tell. It will be interesting to hear how you get on in winter if you do go with this.
     
  6. quasar9

    quasar9 Screwfix Select

    Interesting design. A hybrid where the heat pump warms up the feed water into the gas boiler which then boosts the temperature up to levels needed by traditional radiators. The hot water side is handled entirely by the gas boiler. The idea is the gas boiler throttles down to as little as 10% of its maximum depending on the temp of the feed water. Maybe it can even switch itself off if the heat pump can manage the demand on its own.

    Full air sourced heat pumps require highly insulated houses, hence the hybrid system on offer for older houses. While the system will work well, because you are paying for electricity as well as gas, running costs are tricky to estimate as there is insufficient data on how the mix of energies used over a typical year. Don’t forget although heat pumps will generate heat approximately 4x the input wattage under ideal conditions ( it varies between 2 and 5x, mostly dependent on external temperature) the price differential between gas and electricity is around 5x. Plus there is twice the service cost plus unreliability of such a complex system.

    If you are a dedicated environmentalist, and accept risk of being an early adapter, the system is maybe for you but I suspect most here would plough on with traditional boiler.
     
    Last edited: Jul 1, 2021
  7. Muzungu

    Muzungu Screwfix Select

    I see also that one of the install options is to install the heat pump and use an existing combi boiler.

    The cost would certainly concentrate the mind as it is about 3 times the cost of just a conventional combi, although to be fair the install does include their proprietary combi in addition to the heat pump.

    As @quasar9 makes the point, servicing and reliability of such a complex system as an early adopter would need thinking about. You would be stuck with the installers for future servicing I would have thought.
     
  8. Jimbo

    Jimbo Screwfix Select

    Get an energy survey (which will cost you) and an EPC (which is about £50). The former will provide the sizing and the latter access to RHI.
     
  9. So this Hybrid system will not work on the Air to Heat pump, as it will not heat the house or the Hot water, as this boiler will just work as combi using full condensing gas boiler and there wont be any renewable energy and there will be no saving from this green energy grant and you think it will be £10,000 wasted.

    At the moment there is Potterton combi 28kw.

    This is being done on the Green home energy grant, which will be subsided by the government for £10,000 for the full installation.

    this is the link sent by the agent, when applied. Looking at the link it will do both WATER and HEATING. I am not sure , as the water will need to heatied to atleast 40-60 degrees and Central heating again 60-70 Degrees to warm the house in cold winter. Muzungu said it will be renewable energy for 5 months and then another 7 months the boiler will jsut work on it own , so using full throttle of the gas. I am not if i can free hot water in summer by air to heat pump or it jsut works on it own with the boiler.

    I had choice from another company where they were going to install solar panels to heat the water and have a new boiler and cylinder due 2 bathrooms, Kitchen and i thought let me go for the Hybrid, as this will do both water and heating.

    There is 2 gas fires and it has 16 radiators in the house, as it Mid terraced house with 3 bedrooms, Loft converted, so 4 bedroom.

    There is 2 bathrooms, kitchen and 3 living rooms.

    They have surveyed the property, but not told me which size, but on the quotation it is 4kw and if this 4KW will not warm the house, then would the boiler kick in as normal and heat the house, but in effect it will works as normal combi and using full gas and see no savings at all if the house does not get heated up by the Hybrid Air to heat pump.

    i think surveyor said he will install 32kw BOILER on the existing place, when they will remove the boiler.

    This is my property EPC.

    An Energy Performance Certificate (EPC) was produced for your home in July 2016. (What's this?)

    Your home was given an energy rating of D, which is around average. Most homes appear around grade D.

    Your EPC also tells us:

    Your property is a house
    Your property has 8 habitable rooms
    Your property is heated by mains gas

    55-68 D This is the rating i got from this link https://www.simpleenergyadvice.org.uk/e ... ome-basics
     
  10. The Happy Builder

    The Happy Builder Screwfix Select

    I would not be signing the contract without more details of what is being installed.

    There is not a new combi-boiler included in the quote, so I presume the existing boiler is being kept and reused.

    I’m not going to be convinced that this is a good system without a really good explanation of how it works and the expected running costs.
     
  11. Muzungu

    Muzungu Screwfix Select

    The quote looks as though the combi boiler is being added for "free", it gives a quantity of "1" and a cost of "0". It also looks to me as though the combi will be doing the lion's share of the work. In the summer when the central heating is not needed it appears the ASHP is providing a "preheat" to the combi, so you have, in effect the ASHP running continously with the combi boosting the temp. Can't see how this would be any cheaper than just having the combi running on demand.

    In the winter, when outside temperature is close to zero the combi will be doing all the work, central heating and hot water, as the heat pump will shut off according to the video. Does seem alot of complication and expense for a bit of an unknown result.
     
  12. quasar9

    quasar9 Screwfix Select

    As I said before, electricity is 5x the cost of gas. All thing being equal, I suspect your actual energy bills will be much the same as before although it may have a lower carbon footprint (assuming the electricity coming from renewable source). However you have high installation cost and an unknown quantity in terms of cost of maintenance and life of a heat pump.

    The failure modes of a combi is well known and lasts around 15 years but for heat pumps I have no idea. They will need regassing at some point as a neighbours newly installed system were regassed less than 9 months later.
     
  13. AndBlue

    AndBlue Member

    Couldn't easily read all the quote pages. If you are thinking of a big change and find air source acceptable ( cheapo heating in the summer but almost becomes an electric fan expensive heater in winter), you're gong to double servicing, issues with crossover faults. What happens if one fails do they both stop? have you thought about going all elec heating and shelling out for a load of solar panels then getting elec from one of the newer provider who vary the costs on almost daily rate depending on demand etc.
    There feel of the package offered just doesn't sound right both practically as well as financially.
     
  14. The Happy Builder

    The Happy Builder Screwfix Select

    Without a gas combi boiler there would have to be a large hot water storage cylinder, this looks like a way of shoe horning a heat pump into a house that has an existing combi boiler, but not space for a big hot water cylinder.

    I agree with what @Muzungu says above and I would assume the combi boiler will always provide the hot water. So as you don’t want central heating over the summer the heat pump will only run over the winter, but you will have to leave the heating on 24/7 over the winter to get any benefit from the heat pump, you won’t be able to “flick” the heating on and off as you can with the gas boiler, because it runs at a lower temperature.
     
  15. The Happy Builder

    The Happy Builder Screwfix Select

    You said “i think surveyor said he will install 32kw BOILER on the existing place, when they will remove the boiler“.

    What is the output rating of the existing gas existing boiler?
     
  16. The Happy Builder

    The Happy Builder Screwfix Select

    I have a hot water cylinder and central heating that runs off an old gas boiler which is rated at 11.72 to 14.65 kilowatts and will only replace it when it finally looks like it’s packing up.

    So obviously a 32 kW boiler is more than twice as powerful as mine and I don’t have a heat pump or any other additional heat source, the boiler just runs for longer, but not for as long as a heat pump would.
     
    Muzungu likes this.
  17. Muzungu

    Muzungu Screwfix Select

    My combi is well over 25 years old (Vaillant VCW open flue) and still going strong, although to be fair I have changed a few bits on the water side over the years and a thermostat PCB last year. Can't say my bills are much different from others on the square with newer systems but am aware that it won't go on forever so interested in anything new that comes out.
     
  18. Bob Rathbone

    Bob Rathbone Screwfix Select

    Until we generate all of our electricity from carbon neutral sources, installing a heat pump will not reduce your carbon footprint. Electricity generation is only 40% efficient at best when using fossil fuels, then you have distribution losses. A good gas boiler will be 80% efficient or better, so the boiler will have a smaller carbon footprint then the heat pump. If we all decide to have heat pumps and run electric cars, where is the electricity coming from, how will it get to the user? The current trends in the change to electricity will double or triple the average electricity demand of the home, so our current 23kW supply will need to be increased to a 69kW 3 phase supply. The infrastructure is just not there yet and their is no sign of it on the horizon, we are not building the power stations we need or increasing the size of our electrical distribution system. In reality, the future of home heat lies with hydrogen as the fuel, then the existing gas distribution system can be used, taking the load of the electrical grid.
     
    stevie22 likes this.
  19. Muzungu

    Muzungu Screwfix Select

    It is worth noting that due to the chemical and physical properties of Hydrogen it is simply not possible, at the moment, to use the existing natural gas infrastructure. It would be possible to introduce a low concentrate blend of Hydrogen into the existing infrastructure though.

    There would need to be a a massive upgrade to every mile of the existing infrastructure, and complete replacements of significant parts of it. The hydrogen molecule is the smallest of all molecules and diffuses easily into other materials. Combine that with the pressures required to deliver it efficiently to the home and its high energy per mass, the possibilities of catastrophic failure and leakage are much greater that natural gas. If this is viable within the next 50 years, if at all, I would be surprised, but then again I won't be around to see it.
     

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