Convert BTU per Hour-Square Foot-Fahrenheit to Watts per Square Meter-Kelvin
Instantly convert BTU per Hour-Square Foot-Fahrenheit (BTU/(hr·ft²·°F)) to Watts per Square Meter-Kelvin (W/(m²·K)) with our free online calculator.
Formula: BTU/(hr·ft²·°F) to W/(m²·K) — multiply by 5.67826
Reference Table
| BTU per Hour-Square Foot-Fahrenheit (BTU/(hr·ft²·°F)) | Watts per Square Meter-Kelvin (W/(m²·K)) |
|---|---|
| 1 | 5.67826 |
| 5 | 28.3913 |
| 10 | 56.7826 |
| 25 | 141.957 |
| 50 | 283.913 |
| 100 | 567.826 |
How to Convert BTU per Hour-Square Foot-Fahrenheit to Watts per Square Meter-Kelvin
Formula
To convert BTU per Hour-Square Foot-Fahrenheit (BTU/(hr·ft²·°F)) to Watts per Square Meter-Kelvin (W/(m²·K)): multiply by 5.67826
Step-by-Step
- Start with your value in BTU per Hour-Square Foot-Fahrenheit (BTU/(hr·ft²·°F)).
- Multiply by 5.67826 to perform the conversion.
- The result is your value expressed in Watts per Square Meter-Kelvin (W/(m²·K)).
Conversion Factor
1 BTU/(hr·ft²·°F) = 5.67826 W/(m²·K)
Reverse Factor
1 W/(m²·K) = 0.17611 BTU/(hr·ft²·°F)
Worked Example
Convert 25 BTU per Hour-Square Foot-Fahrenheit to Watts per Square Meter-Kelvin: 25 BTU/(hr·ft²·°F) = 141.957 W/(m²·K)
About BTU per Hour-Square Foot-Fahrenheit (BTU/(hr·ft²·°F))
An imperial heat-transfer-coefficient unit (≈ 5.6783 W/(m²·K) per NIST SP 811). Dominant in US HVAC design, building-envelope U-factor calculations per ASHRAE 90.1, refrigeration system design, and petroleum-industry / chemical-process heat-exchanger specifications per TEMA. ASHRAE Handbook fundamentals tables list film coefficients for building surfaces in BTU/(hr·ft²·°F): indoor air still-film 1.47 BTU/(hr·ft²·°F) (the universally-cited value for interior-wall winter heating-load calculations); exterior with 15 mph wind 6.0; exterior with 7.5 mph summer wind 4.0; roof underside ~1.47-1.61 depending on emissivity. US heat-exchanger overall heat-transfer coefficients (U-values) per Perry's: water-water shell-tube 150-300 BTU/(hr·ft²·°F); steam-condensing-to-water condenser 200-1,500; refrigerant-to-air finned coil 5-15 (air-side dominant); fuel-fired furnace radiation section 1-3 (radiation-dominated). Convert BTU/(hr·ft²·°F) to W/(m²·K) by multiplying by 5.6783; to kW/(m²·K) by multiplying by 5.6783 × 10⁻³.
About Watt per Square Meter-Kelvin (W/(m²·K))
The SI unit of convective heat-transfer coefficient h (ISO 80000-5 §5-11) — the constant of proportionality between surface heat flux and the fluid-to-surface temperature difference in Newton's law of cooling (q = h·ΔT). W/(m²·K) is the universal working unit in heat-exchanger thermal design (shell-and-tube per TEMA standards, plate-frame per ALPEMA, brazed-aluminum-plate-fin per ALPEMA), HVAC system design (per ASHRAE Handbook fundamentals chapters), boiler and condenser sizing per ASME Section VIII, refrigeration evaporator and condenser design, and electronics-cooling thermal analysis. Reference values from Incropera-DeWitt 'Fundamentals of Heat and Mass Transfer' Table 1.1: natural convection in air 2-25 W/(m²·K) (dominant resistance in building envelopes); forced-convection air 25-250 W/(m²·K) (HVAC ducts, cooling fans); natural convection water 50-1,000 W/(m²·K); forced-convection water 100-20,000 W/(m²·K); boiling water 2,500-100,000 W/(m²·K) (nucleate-boiling regime, with critical heat flux at ~1 MW/m²); filmwise condensation 5,000-15,000 W/(m²·K); dropwise condensation 30,000-150,000 W/(m²·K) — 10× higher than filmwise, exploited in advanced condenser surface treatments. Also called the 'film coefficient' in older HVAC literature.
Quick Facts
- 1 BTU per Hour-Square Foot-Fahrenheit equals 5.67826 Watts per Square Meter-Kelvin
- 1 Watt per Square Meter-Kelvin equals 0.17611 BTU per Hour-Square Foot-Fahrenheit
- BTU per Hour-Square Foot-Fahrenheit is a unit of heat transfer coefficient
- Watt per Square Meter-Kelvin is a unit of heat transfer coefficient
- This conversion is commonly used in heat exchanger design, HVAC engineering, and process optimization
- The BTU per Hour-Square Foot-Fahrenheit belongs to the imperial system
- The Watt per Square Meter-Kelvin belongs to the metric system
Common BTU per Hour-Square Foot-Fahrenheit to Watt per Square Meter-Kelvin Conversions
| BTU per Hour-Square Foot-Fahrenheit (BTU/(hr·ft²·°F)) | Watts per Square Meter-Kelvin (W/(m²·K)) |
|---|---|
| 0.01 | 0.0567826 |
| 0.1 | 0.567826 |
| 0.25 | 1.41956 |
| 0.5 | 2.83913 |
| 1 | 5.67826 |
| 2 | 11.3565 |
| 3 | 17.0348 |
| 5 | 28.3913 |
| 10 | 56.7826 |
| 15 | 85.1739 |
| 20 | 113.565 |
| 25 | 141.957 |
| 50 | 283.913 |
| 75 | 425.87 |
| 100 | 567.826 |
| 250 | 1419.57 |
| 500 | 2839.13 |
| 1000 | 5678.26 |
| 5000 | 28391.3 |
| 10000 | 56782.6 |
Understanding BTU per Hour-Square Foot-Fahrenheit
The BTU per Hour-Square Foot-Fahrenheit (symbol: BTU/(hr·ft²·°F)) is a unit of heat transfer coefficient. An imperial heat-transfer-coefficient unit (≈ 5.6783 W/(m²·K) per NIST SP 811). Dominant in US HVAC design, building-envelope U-factor calculations per ASHRAE 90.1, refrigeration system design, and petroleum-industry / chemical-process heat-exchanger specifications per TEMA. ASHRAE Handbook fundamentals tables list film coefficients for building surfaces in BTU/(hr·ft²·°F): indoor air still-film 1.47 BTU/(hr·ft²·°F) (the universally-cited value for interior-wall winter heating-load calculations); exterior with 15 mph wind 6.0; exterior with 7.5 mph summer wind 4.0; roof underside ~1.47-1.61 depending on emissivity. US heat-exchanger overall heat-transfer coefficients (U-values) per Perry's: water-water shell-tube 150-300 BTU/(hr·ft²·°F); steam-condensing-to-water condenser 200-1,500; refrigerant-to-air finned coil 5-15 (air-side dominant); fuel-fired furnace radiation section 1-3 (radiation-dominated). Convert BTU/(hr·ft²·°F) to W/(m²·K) by multiplying by 5.6783; to kW/(m²·K) by multiplying by 5.6783 × 10⁻³.
It belongs to the imperial measurement system.
BTU per Hour-Square Foot-Fahrenheit are commonly used in heat exchanger design, HVAC engineering, and process optimization.
Understanding Watts per Square Meter-Kelvin
The Watt per Square Meter-Kelvin (symbol: W/(m²·K)) is a unit of heat transfer coefficient. The SI unit of convective heat-transfer coefficient h (ISO 80000-5 §5-11) — the constant of proportionality between surface heat flux and the fluid-to-surface temperature difference in Newton's law of cooling (q = h·ΔT). W/(m²·K) is the universal working unit in heat-exchanger thermal design (shell-and-tube per TEMA standards, plate-frame per ALPEMA, brazed-aluminum-plate-fin per ALPEMA), HVAC system design (per ASHRAE Handbook fundamentals chapters), boiler and condenser sizing per ASME Section VIII, refrigeration evaporator and condenser design, and electronics-cooling thermal analysis. Reference values from Incropera-DeWitt 'Fundamentals of Heat and Mass Transfer' Table 1.1: natural convection in air 2-25 W/(m²·K) (dominant resistance in building envelopes); forced-convection air 25-250 W/(m²·K) (HVAC ducts, cooling fans); natural convection water 50-1,000 W/(m²·K); forced-convection water 100-20,000 W/(m²·K); boiling water 2,500-100,000 W/(m²·K) (nucleate-boiling regime, with critical heat flux at ~1 MW/m²); filmwise condensation 5,000-15,000 W/(m²·K); dropwise condensation 30,000-150,000 W/(m²·K) — 10× higher than filmwise, exploited in advanced condenser surface treatments. Also called the 'film coefficient' in older HVAC literature.
It belongs to the metric measurement system.
Watts per Square Meter-Kelvin are commonly used in heat exchanger design, HVAC engineering, and process optimization.
Why Convert BTU per Hour-Square Foot-Fahrenheit to Watts per Square Meter-Kelvin?
Converting between BTU per Hour-Square Foot-Fahrenheit and Watts per Square Meter-Kelvin is a frequent requirement for engineers, scientists, and students working with heat transfer coefficient values. Different industries and regions favour different unit systems, so having a dependable conversion tool saves time and prevents errors in technical calculations. Whether you are verifying a specification sheet, cross-checking simulation results, or preparing a report for an international audience, accurate heat transfer coefficient conversion is essential.
Frequently Asked Questions
How do I convert BTU per Hour-Square Foot-Fahrenheit to Watts per Square Meter-Kelvin?
An imperial heat-transfer-coefficient unit (≈ 5. To convert BTU per Hour-Square Foot-Fahrenheit to Watts per Square Meter-Kelvin, multiply by 5.67826. For example, 25 BTU/(hr·ft²·°F) equals 141.957 W/(m²·K).
How many Watts per Square Meter-Kelvin are in 1 BTU per Hour-Square Foot-Fahrenheit?
There are 5.67826 Watts per Square Meter-Kelvin in 1 BTU per Hour-Square Foot-Fahrenheit.
How many BTU per Hour-Square Foot-Fahrenheit are in 1 Watt per Square Meter-Kelvin?
There are 0.17611 BTU per Hour-Square Foot-Fahrenheit in 1 Watt per Square Meter-Kelvin.
What is the formula for BTU per Hour-Square Foot-Fahrenheit to Watt per Square Meter-Kelvin conversion?
The formula is: multiply by 5.67826. This means 1 BTU/(hr·ft²·°F) = 5.67826 W/(m²·K).
Is a BTU per Hour-Square Foot-Fahrenheit bigger than a Watt per Square Meter-Kelvin?
No. One BTU per Hour-Square Foot-Fahrenheit is smaller than one Watt per Square Meter-Kelvin because 1 BTU/(hr·ft²·°F) equals 5.67826 W/(m²·K), which is greater than 1.
When do you need to convert between BTU per Hour-Square Foot-Fahrenheit and Watts per Square Meter-Kelvin?
The SI unit of convective heat-transfer coefficient h (ISO 80000-5 §5-11) — the constant of proportionality between surface heat flux and the fluid-to-surface temperature difference in Newton's law of cooling (q = h·ΔT). BTU per Hour-Square Foot-Fahrenheit and Watt per Square Meter-Kelvin are both heat transfer coeff units, so conversion comes up whenever one source of information uses one unit and another uses the other — a classic cross-reference challenge in engineering, trade, travel, and everyday life.