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ASHP in Hampshire

batalto · 2021-04-22T13:28:11Z

Hi all, Just wanted to talk you through our upcoming ASHP installation. We live on the south coast, just outside of Portsmouth. The house is a detached home of around 260m2 in footprint. The bottom floor was an extended bungalow and we added a second floor. The first floor is standard construction, brick cavity that's filled and double glazed. The upper floor is made of Structurally Insulated Panels (SIPs) with triple glazing. We had to use SIPs because they are lightweight and so wouldn't affect the shallow bungalow foundations. As an upside SIPS are also extremely efficient in retaining heat and have a very low U value, 0.18. The loft has 200mm of insulation in the middle beneath the floor and 400mm of insulation for everywhere else. We have 8.4kW of solar PV on the roof and 7kWh of battery storage (Pylontech batteries). We also have a Solic solar PV heat controller, which will dump excess solar power into the tank before we export. We've just had our EPC done and we scored very highly A (93) that also provided a heat demand of 34w/m2 which tallies with our ASHP assessment of 36w/m2. The ASHP is a 12kw Midea with a stated SCOP of 3.36 supplied and installed by J A Rees, sourced from Freedom Heat Pumps - total cost just under £10k. We will be replacing our current 32kW gas system boiler and hot water cylinder and using the green homes grant for £5k of the cost and I will paying the other £5k. We qualify for the highest RHI so would expect to get roughly £7200 back over the next 7 years. The boiler will be retained as a backup heating system and isolated from the ASHP system. We have been told this is fine with the RHI as its a backup and not hybrid. The heating is currently set to 45 degrees and we have had no problems. Our main living area has a large bifold door system and west facing. This means we have significant heat loss in the winter and for 2 months its very cold and this makes the room chilly, but not cold. All the other months the solar gain is significant, heating the room and the rest of the house. With the conventional boiler the room is chilly, so I am expecting issues in January heating up the room. We might need to come up with a plan for this room, possibly some thick curtains. The install will be next week and should be very straightforward. The ASHP will go on the drive next to the current power intake. The pipework will go straight through the wall into the current boiler room and tap into the current pipework. The tank will need replacement for one with a larger coil, but more or less everything else will remain the same. The aim is 2 days. Currently our gas is 2.5p and electricity is 14p and the current boiler is 58% efficient (according to the boiler) - this leads to a bill of around £1250 for both gas and electricity for the year. With the ASHP, boiler efficiency and assuming a worse SCOP of 2.7 on the current tariff we expect the bill to fall to just under £1,000 (34,000kw of gas to 7,000kw of electricity). This cost includes a standing charge for gas even though we wont be using it. My plan after we have got used to the ASHP is to upgrade the batteries and add 7kw extra, then move to a new tariff. Agile GO is very interesting as I could fill my batteries at night and expend them during the day. The batteries would store 11.4kw (14kW @ 80% Depth of Discharge). I have estimated this would further drop my bills down to £780

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Air Source Heat Pumps (ASHPs)

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Mars

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28/04/2021 7:22 am

@batalto, our DNO application with Scottish Power took six weeks.

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batalto

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Topic starter 28/04/2021 10:20 pm

SSE have blamed covid for the delay. They are aware we are waiting and hope to have someone come out to look "soon"

That's all I have!!

12kW Midea ASHP - 8.4kw solar - 29kWh batteries
262m2 house in Hampshire
Current weather compensation: 47@-2 and 31@17
My current performance can be found - HERE
Heat pump calculator spreadsheet - HERE

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Kev M

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29/04/2021 7:09 am

@batalto, that's very frustrating and Covid is beginning to wear a bit thin as an excuse. Western Power Distribution did ours all online in February, no visit required, in about 10 days.

I think you can get your GHG voucher extended if you ask.

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Mars

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29/04/2021 10:15 am

@batalto, I have to say that the Covid excuse is wearing a bit thin, so I empathise. Hopefully it'll approved soon. Just hang in there.

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batalto

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Topic starter 20/05/2021 9:40 am

They are coming tomorrow to do the load check - 6/7 weeks after the application. Once its done I can finally move forward

👍

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batalto

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Topic starter 05/06/2021 8:51 pm

Finally got approval back from SSE - install should be in a couple of weeks. Just waiting on confirmed dates

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Kev M

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06/06/2021 8:21 am

Great news, please keep us all updated!

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batalto

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Topic starter 15/06/2021 4:54 pm

Dates for install confirmed for the 29th and 30th of June

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Mars

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16/06/2021 9:54 am

@batalto, that's exciting. Keep us posted.

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batalto

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Topic starter 29/06/2021 10:24 am

Install is underway. Pump arrived fine, however they sent a hot water tank too wide to fit into the loft. Tank says 510mm on the box, but its 560mm when measured...

Hopefully be able to swap it easily - lets see.

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Mars

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29/06/2021 10:30 am

@batalto, good luck. I hope it all goes ahead without any issues.

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JulianC

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29/06/2021 11:29 am

Good luck @batatlo. I’m sure all will go well. I had the opposite problem - they sent a slimmer, but taller tank. Ended up fitting fine. Luckily. As the original wider one would not have fitted 😳

Did you go with a Mixergy tank or one by the ASHP manufacturer?

Daikin Altherma 3H HT 12kWh ASHP with Mixergy h/w cylinder; 4kW solar PV with Solic 200 electric diverter; Honda e and new Hyundai Ioniq 5 N electric vehicles with Myenergi Zappi mk1 charger

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