Discussion ... ASHP(Air/Air) with Solar pv ....

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  • zeupater
    zeupater Posts: 5,352
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    tunnel wrote: »
    Your missing one major point.....how much is a good nights sleep worth when we get a heatwave(uncommon I know)?
    There's been a good few days this year I've had the aircon on all day(for free) and had to get under the duvet at night to keep warm while all the neighbours have their windows wide open trying to keep cool...for me...that's priceless
    Hi

    ... pretty good at shifting humidity too, but above that the air filtration is utterly brilliant !! ....

    HTH
    Z
    "We are what we repeatedly do, excellence then is not an act, but a habit. " ...... Aristotle
    B)
  • zeupater wrote: »
    Hi

    Keep at it, they'll either move their price or you can always go elsewhere! .... you know what it can cost and they obviously do too, but it's your money in your pocket so if they want to get their hands on it they'll need to be realistic on their installation costs ...

    Is the £1800 before VAT, based on 20% VAT or at the reduced 5% rate? .... when looking into systems I was amazed at the (supposed) lack of awareness of the existence of the domestic energy saving 5% rate, so always ask and don't assume .... anyway, research, ask questions and then research more ... if you're talking on the telephone and have a simple installation with power nearby (like ours) let them know that it's simple or they'll load any 'estimated' costs to cover themselves. Never take any notice of an 'estimate', you'll need a firm quote - get them around, explain what you want in terms of equipment and the necessary performance related to pv generation and that it's not really worth you proceeding if the price is above £x .... also, don't discount the guys who quoted £1800 either - just get them around to look at how easy the job is then negotiate ...

    HTH
    Z
    Hi Z
    I fully intend to get proper quotes from a number of companies. Was just testing a few local companies to see if they were interested; seeing how you and Martyn said there were ones that didn't even bother replying to enquiries. At least I have had replies and alternative suggestions.
    Most of the figures so far were all inclusive of VAT, however had ones from one company that are + VAT which would make the Toshiba over £1,800 installed! Will certainly keep a look out for them charging the correct VAT rate of 5%.
    Still doing more research before I ask them round to see how easy the job is and give competitive quotes.
    One question for you; is there any restriction on how close the outside unit can be to a combination boiler flue outlet? Ideally, where we would like to place it is about 1.5 metres away.
  • zeupater
    zeupater Posts: 5,352
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    edited 18 September 2016 at 7:37PM
    ... One question for you; is there any restriction on how close the outside unit can be to a combination boiler flue outlet? Ideally, where we would like to place it is about 1.5 metres away ...
    Hi

    Absolutely no idea, however I'd stay away from placing the outdoor unit directly below the outlet as any condensation drips would be slightly acidic and may have a long-term detrimental effect .... thinking about it there really shouldn't be an issue as all that the unit does is stir the outside air around a little, but that doesn't stop someone making up a planning or safety requirement, so best to check ...

    HTH
    Z
    "We are what we repeatedly do, excellence then is not an act, but a habit. " ...... Aristotle
    B)
  • ed110220
    ed110220 Posts: 1,473
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    Very interesting topic, especially as my sister lives in an electric-only home using an immersion heater for DHW and storage heaters for space heating. I've been recommending replacing the storage heaters (which have reached the end of their life, at least cosmetically) with ASHP in the form of one or two mini split air conditioning units. My dad, who is a builder, regards this with deep skepticism.

    Ed
    Solar install June 2022, Bath
    4.8 kW array, Growatt SPH5000 inverter, 2x Growatt ML33RTA batteries.
    SSW roof. ~22° pitch, BISF house. 12 x 400W Hyundai panels
  • zeupater
    zeupater Posts: 5,352
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    Hi All

    Update as posted on another thread ....
    zeupater wrote: »
    Hi All

    Seeing that it was ~7C overnight and 13C outside now it's 21.4C where I'm sitting and that's after opening some internal doors .... currently generating ~1250W and consuming just about half (630W) and have probably been providing a steady 2.0kW.t to 3kW.t of heat (system ramps up and down as necessary) for most of the the last 5 hours ....

    No GCH or logs burned so far this year ...

    HTH
    Z
    "We are what we repeatedly do, excellence then is not an act, but a habit. " ...... Aristotle
    B)
  • ASavvyBuyer
    ASavvyBuyer Posts: 1,737
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    “ Hi All

    Seeing that it was ~7C overnight and 13C outside now it's 21.4C where I'm sitting and that's after opening some internal doors .... currently generating ~1250W and consuming just about half (630W) and have probably been providing a steady 2.0kW.t to 3kW.t of heat (system ramps up and down as necessary) for most of the the last 5 hours ....

    No GCH or logs burned so far this year ...
    Originally posted by zeupater

    Hi Z

    What are you using to measure the heat output and power input to the air conditioner to compare with the manufactures specification of what it should be? The multiplying of input power by over 5 times to move the heat energy from outside to inside is impressive, but how are you verifying this?
  • zeupater
    zeupater Posts: 5,352
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    edited 15 October 2016 at 10:14PM
    Hi Z

    What are you using to measure the heat output and power input to the air conditioner to compare with the manufactures specification of what it should be? The multiplying of input power by over 5 times to move the heat energy from outside to inside is impressive, but how are you verifying this?
    Hi

    As per earlier post .... when the system was fitted the performance was audit-checked against that published in the manufacturer's engineering databook for the conditions at the time. All you need to measure is the airflow rate (anemometer - weather station or handheld) and temperature difference (IR thermometer) between input & output (multiple readings across each & average), adjust for air density (/pressure) at the time (easiest: internet - we used our weather station) and, of course, the spot power or energy consumed over a known timeslice (whole house monitor clamp on unit or fuses/breakers/appliances switched off) ..... you then know the mass of air, the temperature it's been raised by (therefore by deduction the kW.t) and the power input (kW), so kW.t/kW = COP.

    Now for the validation ... the engineering databook provides thermal performance specifications for various ambient temperatures and deciles of power consumption so simply checking the measured performance against the published figures validates the performance (or not).

    If you're happy with the performance audit there's no need to continue monitoring the heat-pump itself, you'll be able to estimate/gauge the heat provision at any time by knowing the whole house power consumption and simply making an allowance for the normal background usage at the time (which we're pretty familiar with having monitored for years) and making further allowance for COP differences due to power draw and ambient temperatures .... this sounds complex at first, but in the UK you can easily ignore published extremes (because we almost never experience them and that's not what we want the system to do!) & consolidate the rest into wider approximated bands to commit to memory .... it then becomes a case of simple mental arithmetic ...

    HTH
    Z
    "We are what we repeatedly do, excellence then is not an act, but a habit. " ...... Aristotle
    B)
  • ASavvyBuyer
    ASavvyBuyer Posts: 1,737
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    Questions for those of you that already have an Air Source Heat Pump (Air Conditioner).
    1. What servicing arrangements have you found necessary ?
    2. How often does it need servicing ?
    3. What are the approximate costs for each service ?
  • Questions for those of you that already have an Air Source Heat Pump (Air Conditioner).
    1. What servicing arrangements have you found necessary ?
    2. How often does it need servicing ?
    3. What are the approximate costs for each service ?

    I've been meaning to ask about this. I bought my house in January, and the previous owner had installed a split system heat pump with three internal air conditioner units.

    A local company has quoted me £180 + VAT for an annual maintenance contract that covers one call out per year. Is annual servicing/maintenance necessary for domestic systems, and if so does that price sound reasonable?
  • Cardew
    Cardew Posts: 29,036
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    SalsaDanca wrote: »
    I've been meaning to ask about this. I bought my house in January, and the previous owner had installed a split system heat pump with three internal air conditioner units.

    A local company has quoted me £180 + VAT for an annual maintenance contract that covers one call out per year. Is annual servicing/maintenance necessary for domestic systems, and if so does that price sound reasonable?

    This was discussed on MSE some years ago and IIRC a couple of owners stated the only 'routine' servicing required on their Air to Air heat pumps was to clean filters; a DIY task.

    Also there is information here:

    http://forums.moneysavingexpert.com/showthread.php?p=67256086&highlight=heat+pump+servicing#post67256086

    lovesgshp is the most helpful contributor on heat pumps which he installs for a living; albeit in Italy.
    Servicing requirements are quite basic normally and can be completed by the owner. You need to consult the manual, but below are the basics. Operation, should be completed before the heating cycle starts. In all cases, the pump should be isolated from the electrical supply!!!

    1) Clear dust and leaves etc from the fan area.
    2) Clean the particle filter.
    3) Remove dirt/ dust in the cabinet
    4) Clean evaporator fins. ( degreaser then low pressure water jet, to avoid damage) .

    HTH
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