Heat loss calculators and spread sheets

Mars · 2023-01-21T21:04:35Z

Please can you post your favoured heat loss calculators and spreadsheets in this thread so that we can build up a repository for those homeowners that want to undertake their own calculations?

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JamesPa

(@jamespa)

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17/02/2025 12:22 pm

Posted by: @lakey

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How did they adjust the fabric sheet, by just ensuring the total output from the radiators in the house balanced the total heat loss/energy usage even if room by room it didn't match?

Pretty much that, basically (1) make sure that the fabric model represents the actual fabric and (2) adjust the ACH to fit measured loss.

Here is the data I used. This is 2 years worth but 1 would have sufficed

Measured consumption - Copy.pdf

4kW peak of solar PV since 2011; EV and a 1930s house which has been partially renovated to improve its efficiency. 7kW Vaillant heat pump.

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downfield

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17/02/2025 12:39 pm

Posted by: @lakey

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I'll dig deeper into a fan coil radiator.

Have a look at Jaga Strada units. We have them everywhere and they work well.

You can set low medium or high fan speeds at a given flow rate, which changes the heat output (and presumably the DT) without changing the flow rate. We leave ours set to the lowest speed, which is very quiet.

Mitsubishi Zubadan 14kW with Mixergy 210l DHW in 220m2 barn property. 24 solar panels = 9kWp with GivEnergy 5.0kW Hybrid inverter and 19kWh GivE batteries. Jaga Strada fan-assisted rads throughout. Landvac vacuum glazing/triple glazed windows.

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Transparent

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17/02/2025 12:46 pm

Posted by: @lakey

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I've downloaded half hourly from Octopus, I think they gave it in gas m3 though

Yes, most meters (including all Smart Meters) record gas consumption in cubic metres (m³)

To convert to kWh...

Cubic meters (m³) used x calorific value x Gas Correction factor (1.02264) ÷ conversion factor (3.6) = kWh

The calorific value (CV) of gas varies slowly across the UK daily, and there are 69 daily sample points on the network.
The CV used by your energy supplier is printed on your bill.

It will be figure around 39 MJ/m³ (MegaJoules per cubic metre)

You can obtain the CV for all sample points across any range of dates via the Gas Data Portal.

CV data comes under Supplies - Daily Actuals (physical) - Calorific Value
then choose the date range before selecting View Data at the foot of the page.

Save energy... recycle electrons!

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