Convert Units
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📘 Overview: Convert Power & Heat Flow Units Instantly
Power and heat flow rate describe how fast energy is transferred or consumed. Depending on the industry, you might measure this in:
- Watts (W): Standard SI unit for power
- BTU/hour: Common in HVAC and heating systems
- Horsepower (hp): Used in engines and machinery (mechanical, electric, metric variants)
- Ton of refrigeration: Cooling capacity used in HVAC systems
- Atmosphere × volume flow units: Used in physics and thermodynamics (e.g., atm·cm³/min)
This tool allows you to seamlessly convert between these and many other power units. Enable Advanced Mode to access over 20 additional scientific and industrial units like erg/s, ft·lbf/min, cal/s, and BTU/s.
📐 Formula & Methodology
All units convert through the SI base unit watt (W). The formula is:
P(W) = Input × factor_from Result = P(W) ÷ factor_to
For example, to convert 5 kW to BTU/h: 5 × 3412.14 = 17,060.7 BTU/h
📊 Conversion Table (Unit → Watts)
| Unit | Symbol | →W | Note |
|---|---|---|---|
| Watt | W | 1 | SI base unit |
| BTU/hour | BTU/h | 0.293071 | Heating/Cooling systems |
| Horsepower (mechanical) | hp | 745.7 | 550 ft·lbf/s |
| Ton refrigeration (IT) | ton_Ref | 3516.85 | US HVAC cooling |
| atm·cm³/min | atm·ccm | 1.68875×10⁻³ | Used in thermodynamics |
| atm·cm³/s | atm·ccs | 0.101325 | …/s |
| atm·ft³/h | atm·cfh | 0.797001 | …/h |
| atm·ft³/min | atm·cfm | 47.82007 | …/min |
| atm·ft³/s | atm·cfs | 2869.204 | …/s |
| BTUIT/s | BTU_it_s | 1055.056 | High-intensity heating |
| calIT/s | cal_s | 4.1868 | Food or heating systems |
| erg/s | erg_s | 1×10⁻⁷ | CGS system |
| ft·lbf/s | ftlbf_s | 1.3558 | mech |
| ft·lbf/h | ftlbf_h | 3.766×10⁻⁴ | …/h |
| ft·lbf/min | ftlbf_min | 0.022597 | Mechanical energy per minute |
| hp (electric) | hp_elec | 746 | Used in electric motors |
| hp (metric) | hp_metric | 735.5 | 75 m·kgf/s |
| W·h | W_h | 3600 | energy unit |
🧪 Example Conversions
- 5 kW to BTU/h: 5 × 3412.14 = 17,060.7 BTU/h
- 100 hp (mech) to watts: 100 × 745.7 = 74,570 W
- 10 atm·ft³/min to kW: 10 × 47.82007 = 478.2 W → ÷ 1000 = 0.4782 kW
- 300 cal/s to BTU/h: 300 × 4.1868 = 1256.04 W → ÷ 0.293071 ≈ 4287.2 BTU/h
💡 Use Cases
- 💡 Convert horsepower to kilowatts when comparing machinery
- 🏠 Switch between BTU/h and tons of refrigeration in HVAC system sizing
- 📊 Analyze industrial gas flow with atm·cm³/min metrics
- 🔧 Compare mechanical energy (ft·lbf/min) to electrical power
- ⚗️ Use erg/s or cal/s in thermodynamics calculations
❓ Frequently Asked Questions
Why is watt the base unit?
The watt (W) is the SI base unit for power. It ensures accuracy and consistency across mechanical, thermal, and electrical energy flows.
What is a ton of refrigeration?
One ton of refrigeration equals the energy needed to freeze one ton of water in 24 hours. It’s equal to approximately 3.51685 kW or 12,000 BTU/h.
Are all horsepower units the same?
No. Mechanical hp = 745.7 W, electric hp = 746 W, and metric hp ≈ 735.5 W. Be sure to select the right one based on your application.
What is atm·cm³/min used for?
It represents the power of a gas flow under atmospheric pressure and is used in thermodynamics and fluid mechanics.
How accurate are these conversion factors?
All constants are derived from ISO, NIST, and engineering standards. Advanced mode values reflect scientific/industrial approximations.
Can this be used for HVAC load estimation?
Yes! It supports HVAC-specific units like BTU/h, tons of refrigeration, and cal/s, making it ideal for quick system comparisons.
Is this mobile-friendly?
Absolutely. The tool is fully responsive and supports Advanced Mode toggling for a clean mobile experience.