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Derek’s heat pump modelling tool

Air Source Heat Pumps (ASHPs)

Last Post by Derek M 4 years ago

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Derek M

(@derek-m)

Illustrious Member Member

Joined: 5 years ago

Posts: 4425

Topic starter 23/11/2021 8:28 pm

@kev-m

Hi Kev,

I have eventually completed the modelling tool, so please feel free to take it for a test drive to see if any of the wheels fall off. I have set the initial operating parameters to those you supplied, along with the 15% increase in heat demand that you thought applicable. I would suggest that you read the notes on the first sheet, which explains how to initially set the operating parameters and what scenarios it may be possible to investigate.

For those of you who have a 14kW Ecodan of the same model, but are not Kev, you will need to set the initial parameters for your particular system before using the modelling tool.

For those of you who have an Ecodan, but not the 14kW model, but are conversant with Excel Spreadsheets, it will be necessary to change the manufacturers data for the 14kW unit, to that for your particular model.

For those of you who do not have an Ecodan ASHP, you should still be able to see the possible effects that changes to desired indoor air temperature setting, extra insulation, or larger heat emitters may have on your system.

Please provide feedback, good or bad, should you deem it appropriate. All donations to the 'help make Derek M a rich gentleman fund' gratefully accepted. 😀

Ecodan 14kW ASHP Data.xlsx

👍

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Kev M

(@kev-m)

Famed Member Member

Joined: 5 years ago

Posts: 1276

23/11/2021 9:47 pm

@derek-m,

I'll have look tomorrow; very interested in this!

Kev

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Justin

(@justinsb)

Reputable Member Member

Joined: 4 years ago

Posts: 100

24/11/2021 10:31 pm

@derek-m I'm also very interested in this, so I'll have a good look through it as soon as I get a moment, with my own initial parameters.

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Kev M

(@kev-m)

Famed Member Member

Joined: 5 years ago

Posts: 1276

24/11/2021 10:59 pm

post moved

Derek,

I think that the model represents my system very well. At an outside temp of 2C, your model says my ASHP will use about 1.8kW to heat my house to 23C at a flow temp of 35C. That's very close to what I'm seeing. I'll post some graphs in a bit.

Using the playroom and my house and outside temps for 21/11/21, the model predicts I'll use 41.3kWh using the radiators and heat loss figures I told you. I actually used 42.2.

The house was too hot at 23.5 so I dropped the flow temps. On 22/11, again, the model is very close at 32 predicted/33 actual. Interestingly, the ambient temps were very close on both days and dropping from 23.5C to 21.5C made a big difference to the energy used.

I'll try some other days. It would be interesting if the other Ecodan owners had a go.

Good work!

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HJD

(@hjd)

Estimable Member Member

Joined: 4 years ago

Posts: 43

25/11/2021 6:47 am

I will give it a go as we have a very similar system....just need to get my head around Derek's sophisticated spreadsheet!

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Derek M

(@derek-m)

Illustrious Member Member

Joined: 5 years ago

Posts: 4425

Topic starter 25/11/2021 11:10 am

Posted by: @hjd

I will give it a go as we have a very similar system....just need to get my head around Derek's sophisticated spreadsheet!

Hi HJD,

It is fairly simple to use, if you read the instructions under 'Notes', anything that you don't fully understand then just ask. The main thing is try to get your heat demand and heat emitter sizing as accurate as possible.

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