Convert Second-degree Fahrenheit per BTU to Hour-degree Fahrenheit per BTU

Convert Second-degree Fahrenheit per BTU (s·°F/BTU) to Hour-degree Fahrenheit per BTU (h·°F/BTU) instantly and accurately.

Conversion Formula

h·°F/BTU = s·°F/BTU × 0.0002777777778

About Second-degree Fahrenheit per BTU

The second-degree Fahrenheit per BTU (s·°F/BTU) equals (5/9)/1055.05585262 K/W ≈ 5.265 × 10⁻⁴ K/W. Used in US aerospace and nuclear engineering where thermal transient analyses express power as BTU/s and temperature in °F, e.g. rocket engine heat rejection and reactor coolant loop calculations. 1 s·°F/BTU ≈ 5.265 × 10⁻⁴ K/W.

About Hour-degree Fahrenheit per BTU

The h·°F/BTU equals (5/9 × 3600)/1055.05585262 K/W ≈ 1.8956 K/W. It is the traditional US unit for thermal resistance in HVAC, building science, and insulation engineering. A pipe fitting with R = 1 h·°F/BTU passes 1 BTU/h per °F driving difference. Appears in ASHRAE handbooks, ASTM C177, and older US plumbing codes. 1 h·°F/BTU ≈ 1.8956 K/W.

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