Understanding the Units: Cubic Foot per Hour and Litre per Day
A cubic foot per hour (ft³/h) measures how many cubic feet of a fluid pass a point each hour. It is common in the United States for water‑flow, HVAC, and fuel‑delivery calculations.
A litre per day (l/d) measures how many litres flow in a 24‑hour period. The litre is the metric standard for volume, and the per‑day basis aligns with daily‑usage reporting in many industries.
Exact Conversion Factor
The relationship between the two units is fixed:
1 ft³/h = 679.6043 l/d
Conversion Formula
To move from cubic feet per hour to litres per day, multiply by the volume of one cubic foot in litres (28.316846592 L) and then by the number of hours in a day (24 h):
l/d = ft³/h × 28.316846592 × 24
Because 28.316846592 × 24 = 679.604318208, the formula simplifies to:
l/d = ft³/h × 679.6043
Step‑by‑Step Worked Example
Example: Converting 15 ft³/h to litres per day
- Identify the source value: 15 ft³/h.
- Apply the factor: 15 × 679.6043 = 10,194.0645 l/d.
- Result: 15 ft³/h is equivalent to 10,194.0645 l/d.
This single calculation shows how quickly a modest flow rate can become a large daily volume when expressed in metric units.
Practical Applications
- Water‑treatment plants: Engineers often receive pump specifications in ft³/h but need daily output in litres for reporting to regulatory bodies.
- HVAC design: Air‑handling units are sized in ft³/h, yet energy‑consumption models use l/d for water‑based cooling loops.
- Fuel logistics: Diesel delivery trucks in North America quote flow in ft³/h, while fleet managers track consumption in litres per day.
- Scientific research: Laboratory setups may use imperial flow meters, but data analysis software expects metric daily totals.
Cubic Foot Per Hour to Litre Per Day Conversion Table
Each row applies the same rule: multiply cubic feet per hour by 679.6043.
| Cubic Feet per Hour (ft³/h) | Litres per Day (l/d) |
|---|---|
| 1 ft³/h | 679.6043 l/d |
| 2 ft³/h | 1,359.2086 l/d |
| 5 ft³/h | 3,398.0215 l/d |
| 10 ft³/h | 6,796.0432 l/d |
| 20 ft³/h | 13,592.0864 l/d |
| 50 ft³/h | 33,980.2150 l/d |
| 100 ft³/h | 67,960.4318 l/d |
| 500 ft³/h | 339,802.1500 l/d |
Key Takeaways
Converting between cubic feet per hour and litres per day is a simple multiplication by 679.6043. This factor bridges the imperial‑to‑metric gap for any volume‑flow‑rate calculation, whether you’re sizing a pump, planning daily water usage, or translating specifications for an international project.
Ready to apply the conversion? Plug your own ft³/h value into the formula and watch the metric result appear instantly.