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Insulation heat saving: practical guide
This guide explains how to use the Count.ie insulation heat saving. Estimate fabric heat loss avoided by improving a U-value. Follow the inputs, method and worked example below, then compare your own scenario.
Guide written .
Open the Insulation heat saving calculatorWhat to prepare
- Use meter readings, bills, equipment specifications and actual tariff periods where possible.
- Separate power in kW from energy in kWh and daily use from annual use.
- Identify whether efficiency, standing charges and losses are included in the chosen model.
Understand the inputs
The calculation method
Annual heat saving = area × U-value improvement × degree-days × 24 ÷ 1,000. Fuel saving divides by efficiency.
Worked example
Illustrative inputs and their result.
Example inputs
- Insulated area (m²)
- 100
- Existing U-value (W/m²K)
- 1.5
- Improved U-value (W/m²K)
- 0.2
- Annual heating degree-days (K·days)
- 2200
- Heating efficiency (%)
- 85
- Fuel price (€/input kWh)
- 0.1
- Project cost (€)
- 5000
Calculated example result
- Annual Saving
- €807.53
- Heat Saving KWh
- 6,864 kWh
How to interpret the result
Energy consumption and money saved are different outputs. Results based on entered prices or efficiencies are scenarios, not a performance guarantee, installer quote or measured emissions assessment.
Use the same demand and time horizon for each option. Test a less favourable tariff, lower efficiency or lower use to see how sensitive the estimated saving is.
Common mistakes to avoid
- Do not count the same efficiency loss twice.
- Keep standing charges and unit charges separate when the model distinguishes them.
- Check seasonal demand, export restrictions and tariff assumptions before extrapolating.
Assumptions and sources
Degree-days must match the location and base temperature. Ignores thermal bridges, solar gains, occupancy and ventilation. A worse U-value produces a negative saving.
If your case falls outside this scope, use a more suitable calculator or contact us about an unclear method.