# Heat Transfer Browse 7 online Heat Transfer tools for working with heat transfer data and operations in your browser. > Canonical page: https://elysiatools.com/en/tags/heat-transfer ## Overview Explore 7 Heat Transfer tools for working with heat transfer-related data and operations through a browser interface, with no software installation required. ## Frequently asked questions ### What can I do with Heat Transfer tools? You can use the available tools to work with heat transfer-related data and operations through your browser. ### Do I need to install software? No software installation is required. You can access the Heat Transfer tools through the browser interface. ### How is my data handled? Your browser submits operations for processing on Elysia Tools servers. Text inputs are not stored, and uploaded files are automatically deleted after 6 hours. ## Tools - [Cylinder Radial Heat Conduction (Q=2πkL·ΔT/ln(r₂/r₁))](https://elysiatools.com/en/tools/cylinder-radial-conduction): Compute radial steady-state heat conduction through a single-layer cylindrical wall (Fourier's law in cylindrical coordinates): radial heat flow rate Q = 2π·k·L·ΔT/ln(r₂/r₁) (W), inner-surface heat flux q_inner = Q/(2π·r₁·L) (W/m²), outer-surface heat flux q_outer = Q/(2π·r₂·L) (W/m²), and cylindrical thermal resistance R = ln(r₂/r₁)/(2π·k·L) (K/W). k is the thermal conductivity (W/(m·K)); L the cylinder length; r₁ the inner radius, r₂ the outer radius (must have r₂ > r₁ > 0); ΔT the temperature difference (K; a °C difference equals a K difference, a °F difference is converted by ×5/9). ΔT may be negative (indicating reverse heat flow), but k, L, r₁ and r₂ must be positive. Length and radius in m/cm/mm. - [Heat Conduction Calculator (Fourier's Law, q=kΔT/d)](https://elysiatools.com/en/tools/heat-conduction-calculator): Compute 1-D steady-state heat conduction through a flat slab (Fourier's law): heat flux q = k·ΔT/d (W/m²), heat flow rate Q = k·A·ΔT/d (W), and thermal resistance R = d/(k·A) (K/W). k is the thermal conductivity (W/(m·K)); ΔT is the temperature difference (K; a °C difference equals a K difference, a °F difference is converted by ×5/9); d the slab thickness; A the cross-section area. ΔT may be negative (indicating reverse heat flow), but k, d and A must be positive. Thickness in m/cm/mm, area in m²/cm². - [Heat Convection Calculator (Newton's Law, q=hΔT)](https://elysiatools.com/en/tools/heat-convection-calculator): Compute convective heat transfer (Newton's law of cooling): heat flux q = h·ΔT (W/m²), heat flow rate Q = h·A·ΔT (W), and convective thermal resistance R_conv = 1/(h·A) (K/W). h is the convective heat-transfer coefficient (W/(m²·K)); ΔT is the temperature difference between the surface and the fluid (K; a °C difference equals a K difference, a °F difference is converted by ×5/9); A the heat-transfer area. ΔT may be negative (indicating reverse heat flow), but h and A must be positive. Area in m²/cm². - [Heat Exchanger LMTD Calculator (Log Mean Temperature Difference)](https://elysiatools.com/en/tools/heat-exchanger-lmtd): Compute the Log Mean Temperature Difference (LMTD) of a heat exchanger for parallel or counter flow. Parallel flow: ΔT₁ = T_h,in - T_c,in and ΔT₂ = T_h,out - T_c,out; counter flow: ΔT₁ = T_h,in - T_c,out and ΔT₂ = T_h,out - T_c,in. LMTD = (ΔT₁ - ΔT₂)/ln(ΔT₁/ΔT₂), or ΔT₁ when ΔT₁ = ΔT₂. A non-positive terminal difference (temperature cross) is physically impossible and is rejected. Optionally, with the overall heat transfer coefficient U (W/(m²·K)) and the heat transfer area A (m²), the heat transfer rate Q = U·A·LMTD (W) is returned. Temperatures are used only as differences: Δ°C = ΔK and Δ°F ×5/9 = ΔK; the LMTD is reported in K. - [Heat Exchanger ε-NTU Calculator (Effectiveness-NTU Method)](https://elysiatools.com/en/tools/heat-exchanger-ntu): Compute the effectiveness (ε) of a heat exchanger by the ε-NTU method. C*=C_min/C_max (0..1), NTU=U·A/C_min, q_max=C_min·(T_h,in-T_c,in), and ε=q_actual/q_max. Supports four arrangements: Parallel flow ε=\[1-exp(-NTU(1+C*))\]/(1+C*); Counter flow ε=\[1-exp(-NTU(1-C*))\]/\[1-C*·exp(-NTU(1-C*))\], or NTU/(1+NTU) when C*=1; Shell-and-tube 1-2 ε=2/\[1+C*+√(1+C*²)·(1+exp(-NTU√(1+C*²)))/(1-exp(-NTU√(1+C*²)))\]; Crossflow (both unmixed) ε=1-exp{(NTU^0.22/C*)·\[exp(-C*·NTU^0.78)-1\]}. When C*=0 (phase change on one side, boiler/condenser) every arrangement gives ε=1-exp(-NTU). Optionally supply T_h,in and T_c,in to recover the actual heat-transfer rate q=ε·q_max and both outlet temperatures. Temperatures are used only as differences: Δ°C=ΔK and Δ°F×5/9=ΔK. - [Heat Radiation Calculator (Stefan-Boltzmann Law, Q=εσA·T⁴)](https://elysiatools.com/en/tools/heat-radiation-calculator): Compute thermal radiation from a blackbody/grey body (Stefan-Boltzmann law): blackbody emissive power E_b = σ·T⁴ (W/m²), total radiated power Q_rad = ε·σ·A·T⁴ (W); with an optional surrounding temperature T₀ it also computes the net radiative exchange Q_net = ε·σ·A·(T⁴-T₀⁴) (W). σ = 5.670374419e-8 W/(m²·K⁴); ε is the emissivity (0 < ε ≤ 1, blackbody ε=1); T is the ABSOLUTE temperature (K) — °C and °F are first converted to K (this is an absolute temperature, not a difference); A is the radiating area. Area in m²/cm². - [Overall Heat Transfer Coefficient (1/U=ΣR)](https://elysiatools.com/en/tools/overall-heat-transfer-coefficient): Compute the overall heat transfer coefficient for series thermal resistances (flat-wall model): total resistance R_total = Σ R_i (K/W), thermal conductance G = 1/R_total (W/K), area-based coefficient U = 1/(R_total·A) (W/(m²·K)), and if a temperature difference is given the heat flow rate Q = ΔT/R_total (W). Each R_i is a layer resistance already containing the area factor (e.g. convection R_conv=1/(h·A), conduction R_cond=d/(k·A), fouling R_foul=R_f''/A). Enter one resistance (K/W) per line, at least one, all positive. ΔT may be negative (reverse heat flow); a °C difference equals a K difference, a °F difference is converted by ×5/9. ## Related content - [Math](https://elysiatools.com/en/tags/math): Browse 502 online math tools for working with math operations, data, and files in your browser. 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