About This Boiler Steam Unit Calculator
Use this boiler steam unit calculator to convert a spec-sheet reading into the number you actually need. For example, enter a PSI value below and instantly see the equivalent total dynamic head, or convert boiler horsepower into pounds of steam per hour.
The formulas reflect generally accepted engineering rules of thumb. However, because designs vary between manufacturers, you should always verify results against the original equipment specifications, or check with a system engineer, before finalizing a design. Roth Pump is not responsible for errors arising from use of the calculations below.
Why Proper Pump and Condensate Sizing Matters
Proper sizing of pumps, condensate units, and boiler feed water can meaningfully lower installed costs and improve overall system energy efficiency. In fact, most condensate return pump manufacturers triple the rated condensate rate of their pumps simply to offset flow loss at higher temperatures.
Roth Pump, by contrast, doubles the actual condensate rate, because our regenerative pumps handle hotter water more reliably than a typical centrifugal pump. As a result, condensate can return to the boiler at higher temperatures, which shortens the payback period on your initial investment. For related background, see our steam condensate return systems overview, or reference The Engineering Toolbox’s boiler horsepower guide for the underlying unit definitions. Bookmark this boiler steam unit calculator so it is ready the next time you need a quick conversion.
Pressure, Steam, and Boiler Horsepower Conversions
First, use this boiler steam unit calculator to convert pressure, steam, and boiler horsepower readings into the units you need.
| Convert Units | From | To | Formula |
|---|---|---|---|
| PSI to TDH | PSI | 0.00 TDH | PSI x 2.31 = TDH (FEET OF WATER) |
| TDH to PSI | TDH | 0.00 PSI | TDH (FEET OF WATER) / 2.31 = PSI |
| EDR to GPM | EDR | 0.00 GPM | EDR x 0.000496 = GPM |
| BHP to LB / HR | BHP | 0.00 LB / HR | BHP (Boiler HP Power) x 34.5 = LB / HR |
| BHP to BTU / HR | BHP | 0.00 BTU / HR | BHP (Boiler HP Power) x 33479 = BTU / HR |
| BHP to GPM | BHP | 0.00 GPM | BHP (Boiler HP Power) x 0.069 = GPM |
| BHP to EDR | BHP | 0.00 EDR | BHP (Boiler HP Power) x 139 = EDR |
| MBH to BTU | MBH | 0.00 BTU | MBH x 1000 = BTU of Boiler |
| BTU to BHP | BTU | 0.00 BHP | BTU (Of Boiler) / 33479 = BHP (Of Boiler) |
| BTU to EDR | BTU | 0.00 EDR | BTU (Of Boiler) / 240 = EDR (Of Boiler) |
Condensate, Feed Water, and Other Unit Conversions
Next, use the same boiler steam unit calculator for condensate return, feed water, and other common unit measurements.
| Convert Units | From | To | Formula |
|---|---|---|---|
| BHP to EVAP GPM | BHP | 0.00 EVAP GPM | BHP (Boiler HP) x 0.069 = EVAP GPM |
| EVAP GPM to Pump GPM (Boiler Feed) | EVAP GPM | 0.00 Pump GPM | EVAP GPM x 1.5 = Pump GPM (Boiler Feed) |
| EVAP GPM to Pump GPM (Condensate) | EVAP GPM | 0.00 Pump GPM | EVAP GPM x 2 = Pump GPM (Condensate Return) |
| LB / HR Condensate to BTU / HR | LB / HR | 0.00 BTU / HR | LB / HR Condensate x 960 = BTU / HR |
| LB / HR Condensate to EDR | LB / HR | 0.00 EDR | LB / HR Condensate x 4 = EDR |
| LB / HR Steam to GPM | LB / HR | 0.00 GPM | LB / HR Steam x 0.002 = GPM |
| Gallons of Water to LBS. of Water | Gal. | 0.00 LBS. | Gal. of Water x 8.345 = Lbs. of Water |
| Bar to PSI | BAR | 0.00 PSI | Bar x 14.5038 = PSI |
| M3/H to GPM | M3/H | 0.00 GPM | M3/H x 4.402868 = GPM |
| FT³ of Water to Gallons | FT³ of H₂0 | 0.00 Gal. | FT³ of Water x 7.48 = Gal. |
Boiler and Steam Unit Definitions
For quick reference, the abbreviations below explain every unit used throughout this calculator.
- PSI = Pounds per square inch - The pressure resulting from a force of one pound-force applied to an area of one square inch.
- TDH = Total dynamic head - The total equivalent height that a fluid is to be pumped, taking into account friction losses in the pipe.
- EDR = Equivalent Direct Radiation - EDR was originally a measure of the actual surface area of radiators. As radiator (and later convector) design became more complicated and compact, the relationship of actual surface area to EDR became arbitrary. Laboratory methods based on the condensation of steam allowed for very accurate measurements.
- GPM = Gallons Per Minute - GPM is a measure of how many gallons of water flow out of your system each minute.
- BHP = Boiler Horsepower - The boiler's capacity to deliver steam to a system.
- LB / HR = Pound per hour - Mass flow rate. It is particularly useful when dealing with gases or liquids, as volume flow varies more with temperature and pressure.
- BTU / HR = measuring energy per unit time - Equal to 1 BTU being output in an hour.
- MBH = Thousand BTU's per hour.
- BTU = British thermal unit -The amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit.
- Bar = Metric unit of pressure.
- M3/H = Cubic millimeters per hour - flow rate measuring unit.
- FT3 = Cubic foot - The volume of a cube with sides of one foot (0.3048 m) in length.
