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Replacing Worcester oil boiler with an ASHP

JulianC · 2021-03-30T18:15:26Z

I am replacing my 25/32 Worcester oil boiler with an ASHP Had discussions with many suppliers, a lot of whom wouldn't quote because we have 10mm pipe drops to each radiator, from 28mm loft pipes. Anyway: 201m2 bungalow. Built 2001. EPC rating of B after triple glazing, 300mm of loft insulation. We currently use between 1220-1500L of oil per annum. 100A incoming circuit. ASHP approved by DNO (Western Power). 20,500kWh of heating energy required. 3000kWh of hot water demand from the EPC. An energy loss calc and room by room heat demand has been undertaken. This has lead me to select Ecobubl from Winchester to undertake the work. They have proposed a Daikin Altherma 3H HT 18kW ASHP. Also a Mixergy 150L H/W tank - but we are also considering a standard cylinder with a large internal coil, to maximise the ASHP. And a 3kW immersion to use my 4kW of PV and Solic 200 electric diverter. Simple control system, using my current Nest. Had wondered about the Homely Energy control system, but I wonder if this adds complexity. Price is £13,700 for ASHP + Mixergy + buffer tank + installation and support for RHI. I should get back about £10k through RHI. I will take photos before, during and after installation which should be 12 April

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Air Source Heat Pumps (ASHPs)

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JulianC

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Topic starter 14/06/2021 10:08 pm

Update: so my ASHP is effectively off through the summer. H/w is via solar PV and Solic 200 diverter mentioned elsewhere.
But the Daikin in standby mode uses 1.5-2kWh of energy per day. To keep everything in shape I guess? This should be supplied by my solar PV. And matches what Daikin support said.
Has anyone found anything similar?

Daikin Altherma 3H HT 12kWh ASHP with Mixergy h/w cylinder; 4kW solar PV with Solic 200 electric diverter; Honda e and Volvo EX30 Ultra Twin Performance electric vehicles with Myenergi Zappi mk1 & Ohme chargers

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Jeff

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15/06/2021 6:31 am

@julianc good to know.

Does anyone turn their ashp off in the summer or if they are away from home for several weeks?

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Mars

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15/06/2021 8:54 am

Posted by: @jeff

@julianc good to know.

Does anyone turn their ashp off in the summer or if they are away from home for several weeks?

We turned our heat pump off a few weeks ago. Our hot water is heated using our iBoost (connected to our solar PV array) and I'm hoping that it will remain turned off well into August/September.

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Mike Patrick

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15/06/2021 9:53 am

This seems like a variation on the Four Yorkshiremen sketch.

I'm completely out of the running - but I guess the winner will be whoever puts the most back into the grid.

Mike

Grant Aerona HPID10 10kWh ASHP

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JulianC

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Topic starter 15/06/2021 1:11 pm

@mike-patrick “we were so poor…” 😂

For me, it is always trying to use as much of the electric I’ve generated via PV as possible. So reducing draw from the grid and keeping costs down. Very Yorkshire 👍

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JulianC

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Topic starter 16/07/2021 10:17 pm

Solar PV and diverter (Solic) continue to heat hot water in Mixergy tank. Daikin ASHP using about 1.5kWh per day in standby. I need to contact Daikin to ask if this can be scheduled at night when my octopus energy tariff is cheap.

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Derek M

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17/07/2021 3:38 pm

Julian,

Why would you want your ASHP scheduled at night if you have free solar during the day?

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JulianC

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Topic starter 17/07/2021 3:47 pm

Hmmm. Bloody good point @derek-m. I obviously didn’t have my thinking head on 😊

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JulianC

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Topic starter 14/10/2021 6:05 pm

Six month update.
With the system fitted 20th April, thought I’d report.
We have nominally consumed 489kWh of electric for the ASHP. I say nominally because over the summer, we generate quite a lot via solar PV, and I’m only measuring input electric, not where it’s coming from. Also, cost is a little bit difficult to determine, as I have a different day and 4hr night rate with Octopus.
The maximum cost would be £73 at current rates. Which is good.
I have been consuming about 2kWh/day with the system just ticking over. As hot water mostly heated by solar PV electric diverter.
My original MCs estimate was 7500kWh/annum. So the big spend, as you all know, will come in the deep mid-winter.

Any questions, just ask

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Jeff

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14/10/2021 8:17 pm

Just an observation really. 2kw to keep the heat pump ticking over is a shame.

That's more than a fridge freezer running normally.

Feels like heat pump manufacturers need to work on that. Not great to potentially increase the base load of every home by 2kw a day. That's a big increase on the average usage per home.

Good to hear things are uneventful.

Did the installers attempt to profile the 7500 over a year?

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JulianC

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Topic starter 14/10/2021 10:43 pm

I didn’t think 2kWh was too bad. In the summer my solar PV will be providing the electricity and in the winter it will contribute to heating the home.
Yes the MCS installer, Ecobubl profiled the demand and the estimate was 530kWh. So we are a small amount below 👍

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Jeff

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15/10/2021 7:22 am

Posted by: @julianc

I didn’t think 2kWh was too bad. In the summer my solar PV will be providing the electricity and in the winter it will contribute to heating the home.
Yes the MCS installer, Ecobubl profiled the demand and the estimate was 530kWh. So we are a small amount below 👍

Good to know.

Yep, having solar helps, but the majority of homes aren't expected to have solar. That is quite a big leap in the average 8kw a day average load of a home that ofgem use. 25% more electricity just to have the heat pump ticking over. That is a lot of wind turbines. I was just surprised.

Those that are able to use solar won't really notice as you say.

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