ClueLuma

Heat-loss reduction and percentage calculator

Use the same boundary conditions and area before and after insulation.

Units
Savings %=100×(Qbefore−Qafter)Qbefore\text{Savings}\,\% = \frac{100 \times \left(Q_{\text{before}} - Q_{\text{after}}\right)}{Q_{\text{before}}}

Calculator

Enter the values you know and leave one box empty. Calculate finds the empty one, the result or any input.

Btu/h
Btu/h
%

Worked example

Given

  • QbeforeQ_{\text{before}} = 94,000 Btu/h
  • QafterQ_{\text{after}} = 18,000 Btu/h
Savings %=100×(94,000−18,000)94,000≈80.851\text{Savings}\,\% = \frac{100 \times \left(94{,}000 - 18{,}000\right)}{94{,}000} \approx 80.851

Symbols and units

SymbolMeaningUnit
Savings %\text{Savings}\,\%heat-loss reduction%
QbeforeQ_{\text{before}}heat rate before insulationBtu/h
QafterQ_{\text{after}}heat rate after insulationBtu/h

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Results are estimates for study and screening. Check the inputs, units and assumptions before you use them for design, billing or contract decisions.