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nod

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I needed to get some idea of sizing for our sap 

I didn’t really want a quote Though seems quite high 

They are a local company supplying what they say are UK made ASHPs 

Has anyone heard of this type of pump 

If so are they inferior to Mitsubishi or German made 

B6D25946-118B-4BD2-A494-12FE2CF9014D.png

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Looks expensive to me.

 

I paid £11K excl. in 2017 for a 12kW Nibe + Cooling module, with a 500l Nibe UVC, 200l buffer, Modbus module and controller, installed.

 

Nibe seemed more expensive than most, but offered the cooling module, which few others did at the time.

Edited by IanR
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17 minutes ago, IanR said:

Looks expensive to me.

 

I paid £11K excl. in 2017 for a 12kW Nibe + Cooling module, with a 500l Nibe UVC, 200l buffer, Modbus module and controller, installed.

 

Nibe seemed more expensive than most, but offered the cooling module, which few others did at the time.

I’ve just asked that question regarding cooling 

He said no it would effect The efficiency with there unit and disqualify the RHI

Does your cooling work in these temperatures ?

Did it effect RHI?

 

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The cooling has no effect on the efficiency of the ASHP

 

Cooling wasn't initially allowed with RHI, but is now. It changed in 2017 I believe.

 

image.png.8d133666807e2186d93aacbc2828c4a2.png

Ref. https://www.ofgem.gov.uk/environmental-and-social-schemes/domestic-renewable-heat-incentive-domestic-rhi/applicants/eligible-heating-systems


Yes, cooling is effective, but since mine is via the slab, is slow to react, ie. it will take 2-3 hours to lower the slab temp before the cooling effect is felt. I also have cooling available via MVHR, from the same buffer that supplies the UFH, but as I don't cool the buffer below 12°C, it's not that effective via MVHR.

No effect on RHI - COP on ASHP and low flow temp is unchanged, so max RHI allowed on the Nibe I have (F2040-12)

Edited by IanR
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That is a big ASHP and price tag, is it a big house?

 

I have just had a quote back for 9kw R32 Monobloc (£2.1k) and 250 litre pre plumbed cylinder and 50 litre buffer for £4.5k supplied, and £1.5k for the under floor heating parts, at trade prices (No RHI scheme required or MCS20)

 

Beats the £12k quote i got from another supplier just for supply.

 

Now i need to find someone to install it! (any ideas how to track someone down?)

 

 

Edited by Moonshine
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16k and 18kW, jeez that is a hell of a price tag and a huge heat pump.

 

If you want to size your pump the easiest way is to use the heat loss calculator.

 

You know this. You've been knocking around on this forum since day dot so all the discussions r.e. heat loss, ASHP sizing, cooling mode via the slab etc have all been covered at great length whilst you've been here. You're not new to self build either, so you know that RHI is crap if your house is built to a high spec. Surely you are building to a high spec so why bother with RHI? 

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2 hours ago, LA3222 said:

...

You know this. You've been knocking around on this forum since day dot so all the discussions r.e. ....have all been covered at great length whilst you've been here. You're not new to self build either, so you know that ...

 

Members take from BH  content what they will. We cannot make assumptions about content not read. Or read but not remembered.

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48 minutes ago, ToughButterCup said:

 

Members take from BH  content what they will. We cannot make assumptions about content not read. Or read but not remembered.

As Ian says 

Most cherry pick the bits that are most relevant to them 

On our first build we had gas so a Heat pump was never considered 

To be fair if we had access to gas on these plots we would have gone down The gas route again 

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Do you really need such a large ASHP
 

DHW reheat time seems to be the default excuse for sizing such a large unit. My take away from this is that on those rare occasions when I need additional HW quickly, I will just use the immersion. The advice from @PeterW is to also have a slightly larger UVC tank. I was originally thinking of a 300L UVC, but will now get a 400L Telford with twin immersions. 
 

The Heat Loss spreadsheet and LoopCAD calculated that on the coldest winter days I’d need 3kW of heating. I’m thinking of the 9kW unit from Panasonic when it comes time to get this kit. You could also add a heating coil to the MVHR if you wanted some additional heating. I’m going for separate electric heated towel rails in the bathroom because in my current house towels don’t dry for 6 months of the year. MVHR supposedly fixes this too. 
 

The Heat Loss spreadsheet and LoopCAD allow you to enter the air tightness figure, this is really the most important data in the spreadsheet after external outside temperature. It is easy to spec high U-value insulation, but a little trickier to nail an air tightness target. Your final heating requirements could differ quite drastically depending on this. 

Edited by Nick Laslett
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I'm trying to work out my ASHP size requirement too, but unlike nod I've been planning one from the start so have no excuses for not knowing the detail here, especially after reading this forum almost daily for the last 3 years...?. Anywho, I've put my figures into Jeremey's spreadsheet and it comes out with the highest monthly energy input (January) for the average OAT at 1807kWh. Where do I go from here? Thank you in advance

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5 hours ago, Tom said:

I've put my figures into Jeremey's spreadsheet and it comes out with the highest monthly energy input (January) for the average OAT at 1807kWh. Where do I go from here

Is that 1807 kWh the monthly heat load figure, or does it include DHW?

Assuming just the heat load, divide it by the number of hours in January (31 x 24 = 744 [hours]).

Divide the kWh by the January hours and that will be the power needed.

1807 / 744 = 2.43 [kW]

 

So about 3 kW is needed to keep your house warm and allow a little bit of headroom temperature changing and improved efficiency for the ASHP.

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Thanks both, v helpful. So about 5.5kW all in. Does that sound in the right sort of ballpark for a 280m2 single story, ICF build with 3g glazing and MVHR? All depends on the detail I suppose, airtightness etc. Guess I would go for the 8.5kW Ecodan to be on the safe side.

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13 minutes ago, Tom said:

Thanks both, v helpful. So about 5.5kW all in. Does that sound in the right sort of ballpark for a 280m2 single story, ICF build with 3g glazing and MVHR? All depends on the detail I suppose, airtightness etc. Guess I would go for the 8.5kW Ecodan to be on the safe side.

I have a similar size build, high insulation levels, 0.2ACH and have bought a 8.5kW Ecodan with a 300l pre plumbed cylinder.

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1 hour ago, Tom said:

Thanks both, v helpful. So about 5.5kW all in. Does that sound in the right sort of ballpark for a 280m2 single story, ICF build with 3g glazing and MVHR? All depends on the detail I suppose, airtightness etc. Guess I would go for the 8.5kW Ecodan to be on the safe side.

Similar build to yours, 275m2, 3G, MVHR etc and 8.5kW, Ecodan, 300l pre plumber cylinder. Works perfectly for our family of 5.

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44 minutes ago, SteamyTea said:

@joe90 has about 200 m2 I think and his ASHP is 4 or 5 kW.

His DHW demand is lower than most (2 of them) and he is in a mild part of the country.

I think his ACH number was around 1.5.

Yup 5KW ASHP, I do have a woodburner as well but mostly for very cold weather (cave man effect?).

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