The cubic metre per hour is a unit of volumetric flow rate equal to one cubic metre passing a point every hour. Its symbol is m³/h. It is the commercial unit of flow: the one that appears on water bills, gas meters, pump curves and ventilation schedules, because a cubic metre per hour multiplied by the hours of operation gives the volume that is actually paid for.
Domestic water and gas meters read in cubic metres, and the meter's rating is a flow in cubic metres per hour — typically 1.5 or 2.5 for a house, meaning the maximum continuous flow it can measure accurately. A gas meter marked G4 passes 6 cubic metres per hour, which at the calorific value of natural gas is roughly 63 kilowatts, comfortably more than a domestic boiler needs.
Pumps are sold by their curve, and the curve's horizontal axis is almost always cubic metres per hour. A domestic booster pump delivers 2 to 5, a swimming-pool pump 10 to 20, an irrigation pump 50 to 200, and a large water-supply pump thousands. Reading the curve at the required flow gives the head the pump can produce and the power it will draw.
Ventilation is scheduled in the same unit across much of Europe. A dwelling requires roughly 0.5 air changes an hour, so a 250 cubic metre flat needs about 125 cubic metres per hour of fresh air; a restaurant kitchen hood may need 3,000, and a laboratory fume cupboard around 1,000 each. Since the room volume is in cubic metres, using the hour as the time base makes the arithmetic immediate.
Industrial process flows are quoted here whether the fluid is liquid or gas. Cooling towers, boiler feedwater, effluent treatment and compressed-air dryers all carry ratings in cubic metres per hour, and district heating substations are sized from the flow needed to carry the heat at a given temperature difference.
Its relation to the SI unit is a division by 3,600. One cubic metre per second is 3,600 cubic metres per hour, which is why river flows look enormous in this unit and why hydrologists avoid it. The hour is the right base for equipment that runs continuously and is billed monthly.
One cubic metre per hour equals about 0.000278 cubic metres per second, 1,000 litres per hour, or about 4.403 US gallons per minute.
| Unit | Symbol | 1 Cubic meter per hour equals | 1 of these equals | Converter |
|---|---|---|---|---|
| Milliliter per second | mL/s | 277.777777778 mL/s | 0.0036 m³/h | Cubic meters per hour to Milliliters per second |
| Milliliter per minute | mL/min | 16666.6666667 mL/min | 0.00006 m³/h | Cubic meters per hour to Milliliters per minute |
| Milliliter per hour | mL/h | 1000000 mL/h | 0.000001 m³/h | Cubic meters per hour to Milliliters per hour |
| Liter per second | L/s | 0.277777777778 L/s | 3.6 m³/h | Cubic meters per hour to Liters per second |
| Liter per minute | L/min | 16.6666666667 L/min | 0.06 m³/h | Cubic meters per hour to Liters per minute |
| Liter per hour | L/hour | 1000 L/hour | 0.001 m³/h | Cubic meters per hour to Liters per hour |
| Cubic millimeter per second | mm³/s | 277777.777778 mm³/s | 0.0000036 m³/h | Cubic meters per hour to Cubic millimeters per second |
| Cubic millimeter per minute | mm³/min | 16666666.6667 mm³/min | 0.00000006 m³/h | Cubic meters per hour to Cubic millimeters per minute |
| Cubic millimeter per hour | mm³/hour | 1000000000 mm³/hour | 0.000000001 m³/h | Cubic meters per hour to Cubic millimeters per hour |
| Cubic centimeter per second | cm³/s | 277.777777778 cm³/s | 0.0036 m³/h | Cubic meters per hour to Cubic centimeters per second |
| Cubic centimeter per minute | cm³/min | 16666.6666667 cm³/min | 0.00006 m³/h | Cubic meters per hour to Cubic centimeters per minute |
| Cubic centimeter per hour | cm³/h | 1000000 cm³/h | 0.000001 m³/h | Cubic meters per hour to Cubic centimeters per hour |
| Cubic meter per second | m³/s | 0.000277777777778 m³/s | 3600 m³/h | Cubic meters per hour to Cubic meters per second |
| Cubic meter per minute | m³/min | 0.0166666666667 m³/min | 60 m³/h | Cubic meters per hour to Cubic meters per minute |
| Cubic inch per second | in³/s | 16.9510400263 in³/s | 0.0589934304 m³/h | Cubic meters per hour to Cubic inches per second |
| Cubic inch per minute | in³/min | 1017.06240158 in³/min | 0.00098322384 m³/h | Cubic meters per hour to Cubic inches per minute |
| Cubic inch per hour | in³/h | 61023.7440947 in³/h | 0.000016387064 m³/h | Cubic meters per hour to Cubic inches per hour |
| Cubic foot per second | ft³/s | 0.00980962964555 ft³/s | 101.940647724 m³/h | Cubic meters per hour to Cubic feet per second |
| Cubic foot per minute | ft³/min | 0.588577778733 ft³/min | 1.6990107954 m³/h | Cubic meters per hour to Cubic feet per minute |
| Cubic foot per hour | ft³/h | 35.314666724 ft³/h | 0.02831684659 m³/h | Cubic meters per hour to Cubic feet per hour |
| Fluid ounce per second | fl oz/s | 9.77641103552 fl oz/s | 0.102287025 m³/h | Cubic meters per hour to Fluid ounces per second |
| Fluid ounce per minute | fl oz/min | 586.584662131 fl oz/min | 0.00170478375 m³/h | Cubic meters per hour to Fluid ounces per minute |
| Fluid ounce per hour | fl oz/h | 35195.0797279 fl oz/h | 0.0000284130625 m³/h | Cubic meters per hour to Fluid ounces per hour |
| Gallon per second | gal/s | 0.061102568972 gal/s | 16.365924 m³/h | Cubic meters per hour to Gallons per second |
| Gallon per minute | gal/min | 3.66615413832 gal/min | 0.2727654 m³/h | Cubic meters per hour to Gallons per minute |
| Gallon per hour | gal/h | 219.969248299 gal/h | 0.00454609 m³/h | Cubic meters per hour to Gallons per hour |
| US Gallon per second | gal US/s | 0.073381125655 gal US/s | 13.6274824224 m³/h | Cubic meters per hour to US Gallons per second |
| US Gallon per minute | gal US/min | 4.4028675393 gal US/min | 0.22712470704 m³/h | Cubic meters per hour to US Gallons per minute |
| US Gallon per hour | gal US/h | 264.172052358 gal US/h | 0.003785411784 m³/h | Cubic meters per hour to US Gallons per hour |