Buying Process Heat from a Catalogue Written in kcal/h
Ask three suppliers to quote a thermal oil heater and one of them will answer in kilocalories per hour. Chinese, Korean, Turkish and Italian process-heating catalogues have printed six-figure kcal/h ratings for decades, and plenty still do. When the rest of your specification, your pipework calculations and your energy budget are in kilowatts, that rating has to be translated before anything can be compared or signed off.
Where the Kilocalorie Rating Still Turns Up
Thermal oil heater ranges
Hot-air generators and dryers
Gigacalories in district energy tenders
Legacy asset lists and bid documents
Putting a kcal/h Quotation Beside a kW Specification
Two offers, two unit systems, one shortlist. The conversion is the easy half; knowing which rating you were handed is the half that costs money.
Type the catalogue rating exactly as printed
Six- and seven-figure numbers go in without trouble: spaces are ignored, a comma is accepted as a decimal mark, and the kilowatt value appears as you type. For a Gcal/h figure, add six zeros first.
Establish whether it is output or fuel input
A supplier may be quoting the heat delivered to the oil or the steam, or the energy content of the fuel burned to produce it. The two differ by the efficiency on the nameplate, so settle it before comparing two offers.
Reverse it to state your duty in their units
The swap button (↔) runs kW → kcal/h, which is what you want when your process needs 350 kW and the supplier's range is listed in kcal/h steps — that duty lands just above their 300 000 model.
Move the value into the tender comparison
Copy hands over the plain number, so the kW column of your evaluation sheet stays numeric and the totals at the bottom keep working.
Industrial Heating Equipment Rated in Kilocalories per Hour
Catalogue sizes you are likely to meet, with the kilowatt duty behind each. Every kW value is the kcal/h rating multiplied by 0.001163.
| Equipment | Catalogue rating | Heat output (kW) | Typical duty |
|---|---|---|---|
| Package burner, small | 50 000 kcal/h | 58.15 kW | Small dryer or wash tank |
| Thermal oil heater, entry size | 100 000 kcal/h | 116.3 kW | Single press or reactor jacket |
| Industrial baking oven | 150 000 kcal/h | 174.45 kW | Continuous tunnel oven |
| Hot-air generator | 200 000 kcal/h | 232.6 kW | Paint line or timber kiln |
| Thermal oil heater, mid range | 300 000 kcal/h | 348.9 kW | Laminating or calender line |
| Package steam generator | 500 000 kcal/h | 581.5 kW | Process steam for a small plant |
| Rotary dryer burner | 1 000 000 kcal/h | 1 163 kW | Aggregate or mineral drying, 1 Gcal/h |
| Thermal oil heater, large | 2 000 000 kcal/h | 2 326 kW | Multi-user hot-oil ring main |
The pattern is worth memorising: a million kcal/h is 1 163 kW, so every extra 100 000 on the catalogue label adds 116.3 kW of duty. With that anchor in your head you can size a shortlist mentally and reach for the converter only for the figure that ends up on the requisition.
What Speeds Up a Catalogue Comparison
A whole model range converted in one sitting
Enter each catalogue size in turn and the kW duty follows immediately, so a supplier's ten-model range becomes a kilowatt column in under a minute.
Seven-figure ratings stay readable
Thousands are spaced out in the result, so 2 000 000 kcal/h reads back as 2 326 kW rather than a wall of digits you have to count with a fingertip.
State your duty in the supplier's units
One press of ↔ turns a kW requirement into the kcal/h number their sales office recognises, which shortens the email exchange considerably.
Megawatts and BTU/h on the same unit list
Searchable selectors on both sides reach MW for network-scale duties and BTU/h for North American equipment, all from the same kcal/h entry.
Process Heating Rating Questions
Why do Asian and older European heater catalogues rate output in kcal/h?
Process heat calculations were done in calorie units long before SI became mandatory, and manufacturers built whole model families around round kcal/h numbers. Renaming a 300 000 model would break part numbers, spare-part lists and the sales team's shorthand, so the label survived even as the technical annexes switched to kilowatts.
Is the plate figure the fuel fired or the heat delivered to the process?
It depends on the maker, which is precisely why it has to be asked. Burner manufacturers usually publish firing rate — the energy in the fuel — while heater and generator makers usually publish useful output. Between the two sits thermal efficiency, so a 500 000 kcal/h output claim and a 500 000 kcal/h input claim describe machines around 10 % apart in real duty.
Do a thermal oil heater and a steam generator of the same kcal/h behave alike?
They move the same heat per hour, but not in the same manner. Thermal oil carries sensible heat, so the duty depends on flow rate and the temperature drop across the user, and it reaches 300 °C without pressurising the circuit. Steam delivers latent heat at a fixed temperature for a given pressure and transfers it far faster at the surface. Matching the kW figure is where the comparison starts, not where it ends.
A tender is written in Gcal/h — how does that relate to my kW figure?
A gigacalorie per hour is a million kcal/h, so it works out at 1 163 kW, or 1.163 MW. District heating substations, refinery duties and large network exchangers are routinely written this way: 5 Gcal/h is 5.815 MW and 20 Gcal/h is 23.26 MW. Add the six zeros and convert as normal.
What does the efficiency percentage on the plate change in my sums?
It sets the size of the fuel connection and the running cost, not the heat your process receives. Divide the output duty by the efficiency to get the firing rate: 348.9 kW of output at 88 % calls for about 396 kW of fuel. That input figure is what sizes the gas train, the oil line and the flue, and what the annual energy bill is built on.
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