{"chart":"heat-transfer-conversion-chart","generatedFrom":"All Unit Conversions shared conversion library","tables":[{"title":"Multiply-by factors","headers":["Quantity","From","To","Multiply by"],"rows":[["Thermal conductivity k","BTU/(h·ft·°F)","W/(m·K)","1.730735"],["Thermal conductivity k","W/(m·K)","BTU/(h·ft·°F)","0.5777893"],["Thermal conductivity k","BTU·in/(h·ft²·°F)","W/(m·K)","0.1442279"],["Thermal conductivity k","W/(m·K)","BTU·in/(h·ft²·°F)","6.933472"],["Thermal conductivity k","kcal/(h·m·°C)","W/(m·K)","1.163"],["U-value, heat transfer coefficient","BTU/(h·ft²·°F)","W/(m²·K)","5.678263"],["U-value, heat transfer coefficient","W/(m²·K)","BTU/(h·ft²·°F)","0.1761102"],["U-value, heat transfer coefficient","kcal/(h·m²·°C)","W/(m²·K)","1.163"],["Thermal resistance R","h·ft²·°F/BTU (R-value)","m²·K/W (RSI)","0.1761102"],["Thermal resistance R","m²·K/W (RSI)","h·ft²·°F/BTU (R-value)","5.678263"],["Heat flux","BTU/(h·ft²)","W/m²","3.154591"],["Heat flux","W/m²","BTU/(h·ft²)","0.3169983"],["Specific heat capacity","BTU/(lb·°F)","kJ/(kg·K)","4.1868"],["Specific heat capacity","kcal/(kg·°C)","kJ/(kg·K)","4.1868"],["Specific heat capacity","kJ/(kg·K)","BTU/(lb·°F)","0.2388459"]]},{"title":"Insulation R-value to RSI and U-value","headers":["R-value (h·ft²·°F/BTU)","RSI (m²·K/W)","U (W/m²·K)","U (BTU/h·ft²·°F)"],"rows":[["1","0.18","5.678","1.0000"],["2","0.35","2.839","0.5000"],["3","0.53","1.893","0.3333"],["4","0.70","1.420","0.2500"],["5","0.88","1.136","0.2000"],["6","1.06","0.946","0.1667"],["8","1.41","0.710","0.1250"],["10","1.76","0.568","0.1000"],["11","1.94","0.516","0.0909"],["13","2.29","0.437","0.0769"],["15","2.64","0.379","0.0667"],["19","3.35","0.299","0.0526"],["21","3.70","0.270","0.0476"],["25","4.40","0.227","0.0400"],["30","5.28","0.189","0.0333"],["38","6.69","0.149","0.0263"],["40","7.04","0.142","0.0250"],["49","8.63","0.116","0.0204"],["50","8.81","0.114","0.0200"],["60","10.57","0.095","0.0167"]]},{"title":"U-value (W/m²·K) to imperial U and R-value","headers":["U (W/m²·K)","U (BTU/h·ft²·°F)","R-value (IP)","RSI (m²·K/W)"],"rows":[["0.1","0.0176","56.8","10.00"],["0.11","0.0194","51.6","9.09"],["0.13","0.0229","43.7","7.69"],["0.15","0.0264","37.9","6.67"],["0.16","0.0282","35.5","6.25"],["0.18","0.0317","31.5","5.56"],["0.2","0.0352","28.4","5.00"],["0.25","0.0440","22.7","4.00"],["0.28","0.0493","20.3","3.57"],["0.3","0.0528","18.9","3.33"],["0.35","0.0616","16.2","2.86"],["0.45","0.0792","12.6","2.22"],["0.5","0.0881","11.4","2.00"],["0.7","0.1233","8.1","1.43"],["1","0.1761","5.7","1.00"],["1.4","0.2466","4.1","0.71"],["1.6","0.2818","3.5","0.63"],["2","0.3522","2.8","0.50"],["2.8","0.4931","2.0","0.36"],["4.8","0.8453","1.2","0.21"],["5.7","1.0038","1.0","0.18"]]},{"title":"Thermal conductivity","headers":["k (W/m·K)","BTU/(h·ft·°F)","BTU·in/(h·ft²·°F)","kcal/(h·m·°C)"],"rows":[["0.02","0.011556","0.13867","0.017197"],["0.025","0.014445","0.17334","0.021496"],["0.03","0.017334","0.208","0.025795"],["0.035","0.020223","0.24267","0.030095"],["0.04","0.023112","0.27734","0.034394"],["0.05","0.028889","0.34667","0.042992"],["0.1","0.057779","0.69335","0.085985"],["0.15","0.086668","1.04","0.12898"],["0.2","0.11556","1.3867","0.17197"],["0.5","0.28889","3.4667","0.42992"],["1","0.57779","6.9335","0.85985"],["2","1.1556","13.867","1.7197"],["5","2.8889","34.667","4.2992"],["10","5.7779","69.335","8.5985"],["16","9.2446","110.94","13.758"],["50","28.889","346.67","42.992"],["100","57.779","693.35","85.985"],["200","115.56","1,386.7","171.97"],["237","136.94","1,643.2","203.78"],["401","231.69","2,780.3","344.8"]]},{"title":"Heat transfer coefficient h","headers":["h (W/m²·K)","BTU/(h·ft²·°F)","kcal/(h·m²·°C)"],"rows":[["2","0.35222","1.7197"],["5","0.88055","4.2992"],["10","1.7611","8.5985"],["25","4.4028","21.496"],["50","8.8055","42.992"],["100","17.611","85.985"],["250","44.028","214.96"],["500","88.055","429.92"],["1,000","176.11","859.85"],["2,500","440.28","2,149.6"],["5,000","880.55","4,299.2"],["10,000","1,761.1","8,598.5"],["20,000","3,522.2","17,197"],["100,000","17,611","85,985"]]},{"title":"Typical convection heat transfer coefficients","headers":["Process","h (W/m²·K)","h (BTU/h·ft²·°F)"],"rows":[["Free convection, gases","2–25","0.35–4.4"],["Free convection, liquids","50–1,000","8.8–176"],["Forced convection, gases","25–250","4.4–44"],["Forced convection, liquids","100–20,000","17.6–3,522"],["Boiling or condensation","2,500–100,000","440–17,611"]]},{"title":"Heat flux","headers":["W/m²","BTU/(h·ft²)","kW/m²"],"rows":[["1","0.317","0.001"],["10","3.17","0.01"],["50","15.85","0.05"],["100","31.7","0.1"],["500","158.5","0.5"],["1,000","317","1"],["1,361","431.43","1.361"],["5,000","1,585","5"],["10,000","3,170","10"],["100,000","31,700","100"]]},{"title":"Specific heat of liquid water at 1 atm (IAPWS-IF97)","headers":["T (°C)","T (°F)","cp (kJ/kg·K)","cp (BTU/lb·°F)"],"rows":[["0.01","32.02","4.2194","1.0078"],["10","50","4.1954","1.0021"],["20","68","4.1848","0.9995"],["25","77","4.1819","0.9988"],["30","86","4.1800","0.9984"],["40","104","4.1786","0.9980"],["50","122","4.1796","0.9983"],["60","140","4.1828","0.9990"],["70","158","4.1881","1.0003"],["80","176","4.1955","1.0021"],["90","194","4.2050","1.0043"],["99","210.2","4.2154","1.0068"]]},{"title":"Heat transfer formulas","headers":["Formula","Meaning","Worked example"],"rows":[["Q = m × c × ΔT","Heat to change the temperature of a mass","Heating 10 kg of water by 50 K: 10 × 4.18 × 50 = 2,090 kJ (0.58 kWh)"],["q = k × A × ΔT ÷ L","Conduction through a slab","k 0.04, 10 m², 20 K, 0.1 m: q = 80 W"],["q = U × A × ΔT","Heat loss through a wall or window","U 0.3, 50 m², 20 K: q = 300 W"],["U = 1 ÷ ΣR","U-value from the layer resistances (including surfaces)","R total 3.33 m²·K/W: U = 0.30 W/m²·K"],["R = L ÷ k","Resistance of one layer","100 mm at k 0.035: R = 2.86 m²·K/W"]]}]}