Terminal temperature difference, overall U and cleanliness factor of a surface condenser, the back-pressure you should be getting, and the turbine power and money lost to the excess.
USD 49 one-time purchase
Need it once? Use it online: check your data free, unlock results from USD 9 for 3 runs.
What it does
Heat balance and temperatures
Cooling-water and steam duty with closure shown, saturation temperature, TTD, LMTD and condensate subcooling.
Cleanliness factor
Overall U and cleanliness against a clean-tube U estimated from tube material, gauge and water velocity, or against your own design value.
Expected back-pressure
What the vacuum should be for your cooling water and load, and the excess over it.
Air in-leakage indicators
Air-vapour depression at the off-take, air partial pressure and subcooling, each with a typical limit.
Cost of the excess
Turbine power lost per kPa, energy per year and its value at your price.
What-if tables
Cooling water inlet temperature and flow (net of pump power), cleanliness and plugged tubes.
Built for engineers
- Visible formulas — nothing hidden, so you can check every step.
- Fully referenced — methods from the standard references, checked against their published worked examples.
- Safe to share — sheets are protected against accidental edits, with an open password so you can still customise.
- Built-in input checks — clear warnings for impossible inputs and values outside typical ranges.
For engineering estimates; verify against site data. Code-based methods are aligned with the publicly documented procedure; they are not a licensed reproduction or a certification.
Preview the workbook
An illustration of the sheet layout of this workbook, not a screenshot of calculated results. Select the image to enlarge it. For questions before you buy, email [email protected].
Specification and checks
| Format | Excel workbook (.xlsx), no macros |
| Version | v1.0 |
| Works in | Excel 2010 or later, Windows and Mac |
| Units | SI, US and British, mixed freely |
| Includes | Guide tab with method and references, calculator, print-ready report |
| Checked against | 294 recalculated runs against an independent Python model (CoolProp steam and water, numerical solver): largest deviation 0.07 %, results otherwise within 0.03 %. |
| Free version | Try the free LMTD calculator |
Online tool or Excel workbook?
| Online tool | Excel workbook (this page) | |
|---|---|---|
| What it does | The same sheet as the Excel workbook, run in your browser | Terminal temperature difference, overall U and cleanliness factor of a surface condenser, the back-pressure you should be getting, and the turbine power and money lost to the excess. |
| Cost | Check your inputs free. Results: 3 runs for USD 9, or every online tool for USD 15 a month (USD 99 a year) | USD 49 once, yours to keep |
| Input checks and findings | Every input checked; findings with the unlocked results | Every input checked, with findings and recommendations |
| Report for your calculation file | Printable results sheet | Print-ready report with your plant, tag, document number, revision and sign-off |
| Formulas | Method described in the guide | Every formula visible in its cell |
| Save, edit and rerun your cases | Each run separately | Yes: keep and edit your own file |
| Works offline, on a plant PC | No, needs the internet | Yes: Excel 2010 or later, Windows and Mac |
Online access and the Excel workbook are separate licences: one does not include the other.
Compatibility, licence and support
| File | Excel workbook (.xlsx), no macros, version v1.0; works in Excel 2010 or later on Windows and Mac. Sheets are protected against accidental edits, with an open password so you can customise. |
| Licence | Single user. A team licence (up to 5 named users) is 3 × the shop price; site licences on request — licence terms. |
| Updates | Updates to this major version are included; download them again from the link in your receipt. |
| Support | Email [email protected] with your order number — questions on the method, your inputs or your results are welcome. |
| Refunds | If the tool does not work as described, or has an error we cannot fix, email [email protected] with your order number within 14 days of purchase and we will refund you in full. Refunds are not offered for a change of mind once a file has been downloaded. Read the full refund policy. |