Cubic feet per hour (ft³/h) to Litres per hour (l/h) conversion

Understanding Cubic feet per hour to Litres per hour Conversion

Cubic feet per hour ($ft^3/h$) and litres per hour ($l/h$) are both units used to measure volumetric flow rate, which describes how much volume moves through a system in one hour. Cubic feet per hour is commonly associated with U.S. customary and imperial-style engineering contexts, while litres per hour is widely used in metric-based technical, industrial, and scientific applications.

Converting between these units is useful when comparing equipment specifications, interpreting international documentation, or standardizing measurements across different industries. It is especially relevant for ventilation systems, gas supply rates, water dosing systems, and fluid transfer equipment.

Conversion Formula

To convert from cubic feet per hour to litres per hour, use the verified relationship:

$$1 \, ft^3/h = 28.316831998815 \, l/h$$

So the general formula is:

$$l/h = ft^3/h \times 28.316831998815$$

For the reverse conversion, the verified relationship is:

$$1 \, l/h = 0.03531468492103 \, ft^3/h$$

So the reverse formula is:

$$ft^3/h = l/h \times 0.03531468492103$$

Step-by-Step Example

Suppose a ventilation device moves air at a rate of $18.5 \, ft^3/h$.

1. Write the formula

$$l/h = ft^3/h \times 28.316831998815$$

2. Substitute the value

$$l/h = 18.5 \times 28.316831998815$$

3. Calculate

$$l/h = 523.8613919780775$$

Therefore:

$$18.5 \, ft^3/h = 523.8613919780775 \, l/h$$

Real-World Examples

• A small laboratory gas flow setup rated at $2.4 \, ft^3/h$ corresponds to $67.960396797156 \, l/h$.
• A compact ventilation line carrying $15 \, ft^3/h$ is equal to $424.752479982225 \, l/h$.
• A fluid dosing or transfer system operating at $42 \, ft^3/h$ converts to $1189.30694395023 \, l/h$.
• An industrial blower with a low-flow specification of $75 \, ft^3/h$ corresponds to $2123.762399911125 \, l/h$.

Interesting Facts

• The cubic foot is a volume unit derived from the foot, a traditional length unit used in U.S. customary and some imperial measurement contexts. Background on the foot and related customary units is available from NIST: https://www.nist.gov/pml/owm/metric-si/si-units
• The litre is a metric unit of volume commonly used for liquids and gases, and it is accepted for use with the International System of Units. A general reference is available on Wikipedia: https://en.wikipedia.org/wiki/Litre

Notes on Using These Units

Cubic feet per hour is often seen in equipment catalogs, HVAC references, and gas handling specifications where imperial-style units are still standard. Litres per hour is more common in international product documentation, water treatment, chemical processing, and scientific reporting.

Because both units describe volume per unit time, the conversion does not change the physical flow itself; it only changes the numeric expression into a different measurement system. This makes the conversion important for accurate comparison of technical data sheets and operating ranges.

When reading a specification, it is also important to distinguish volume flow rate from mass flow rate. Units such as $ft^3/h$ and $l/h$ describe the space occupied by a fluid per hour, not its mass.

In practical settings, these units may be used for:

• air movement in ducts or enclosures
• natural gas or other gas delivery systems
• water pumping and metering
• chemical feed systems
• laboratory instrumentation

For quick reference, the key factor remains:

$$1 \, ft^3/h = 28.316831998815 \, l/h$$

and the reverse factor is:

$$1 \, l/h = 0.03531468492103 \, ft^3/h$$

These verified factors make it possible to convert values consistently between customary and metric flow-rate measurements.

How to Convert Cubic feet per hour to Litres per hour

To convert Cubic feet per hour (ft$^3$/h) to Litres per hour (l/h), multiply the flow rate by the conversion factor between cubic feet and litres. Since the time unit is already “per hour” on both sides, only the volume unit changes.

1. Write the conversion factor:
   Use the known relationship between cubic feet and litres:

   $$1\ \text{ft}^3/\text{h} = 28.316831998815\ \text{l/h}$$

2. Set up the conversion formula:
   Multiply the given value in ft$^3$/h by the conversion factor:

   $$\text{l/h} = \text{ft}^3/\text{h} \times 28.316831998815$$

3. Substitute the given value:
   For $25\ \text{ft}^3/\text{h}$:

   $$\text{l/h} = 25 \times 28.316831998815$$

4. Calculate the result:
   Perform the multiplication:

   $$25 \times 28.316831998815 = 707.92079997036$$

5. Result:

   $$25\ \text{ft}^3/\text{h} = 707.92079997036\ \text{l/h}$$

If you are converting many values, keep the factor $28.316831998815$ handy for quick multiplication. Always double-check that both rates use the same time unit before converting.

What is the formula to convert Cubic feet per hour to Litres per hour?

To convert Cubic feet per hour to Litres per hour, multiply the flow rate in ft$^3$/h by the verified factor $28.316831998815$. The formula is $l/h = ft^3/h \times 28.316831998815$. This gives the equivalent volume flow rate in litres per hour.

How many Litres per hour are in 1 Cubic foot per hour?

There are exactly $28.316831998815$ l/h in $1$ ft$^3$/h. This value comes directly from the verified conversion factor. It is useful as the base reference for all ft$^3$/h to l/h conversions.

Why would I convert Cubic feet per hour to Litres per hour?

This conversion is common when comparing flow rates across systems that use different measurement standards. For example, HVAC, gas flow, water treatment, and laboratory equipment may list capacity in either ft$^3$/h or l/h. Converting helps ensure specifications match correctly.

How do I convert a larger flow rate from ft3/h to l/h?

Multiply the number of Cubic feet per hour by $28.316831998815$. For example, if a device is rated in ft$^3$/h, applying $l/h = ft^3/h \times 28.316831998815$ gives the equivalent litre-per-hour value. This method works for any positive flow rate.

Is Cubic feet per hour the same as Litres per hour?

No, they are different units of volumetric flow rate. Cubic feet per hour is based on imperial or US customary volume units, while Litres per hour uses the metric system. They measure the same type of quantity, but with different unit sizes.

When should I use Litres per hour instead of Cubic feet per hour?

Litres per hour is often preferred in metric-based industries, product datasheets, and international technical documentation. It can also be easier to interpret for smaller liquid or gas flow rates. Using l/h improves consistency when working with other metric units.