Frequently Asked Questions
- What is the pricing for access to the HeatSinkCalculator?
- Do I need any special training to use the HeatSinkCalculator?
- Why can't I simply use the thermal resistance value provided by the heat sink manufacturer to calculate the heat source temperature?
- I already use CFD software. Why should I use the HeatSinkCalculator?
- What methodology is used by the HeatSinkCalculator to calculate the results?
- How accurate are the HeatSinkCalculator results?
- Does the HeatSinkCalculator account for laminar and turbulent flow?
- Will the HeatSinkCalculator allow me to compare several heat sink designs at once?
- Can I optimize the heat sink dimensions with a fixed approach velocity or flow rate?
- What can the dimensional optimization find?
- Can the HeatSinkCalculator analyse liquid-cooled heat sinks?
What is the pricing for access to the HeatSinkCalculator?
Go to the sign up page to see the current pricing for access to the calculator.
Do I need any special training to use the HeatSinkCalculator?
No special training is needed to use the HeatSinkCalculator. You just need to know the physical dimensions, material and flow conditions of the heat sink. No advanced thermal analysis knowledge is required.
Why can't I simply use the thermal resistance value provided by the heat sink manufacturer to calculate the heat source temperature?
The thermal resistance value provided by the manufacturer is only valid for the heat source size used by the manufacturer to determine the thermal resistance. As the heat source dimensions are varied the thermal resistance will change. Also in the case of natural convection cooled heat sinks the manufacturer's thermal resistance value is again only valid for the heat source size and power dissipation used by the manufacturer when calculating this value. The natural convection thermal resistance is highly dependent on the temperature of the heat sink and hence the power dissipation of the heat source. If your design has a different heat source size and/or power dissipation the natural convection thermal resistance can be significantly different from the manufacturer's stated value.
I already use CFD software. Why should I use the HeatSinkCalculator?
CFD analysis is an excellent tool that can be used to accurately analyse heat sinks in various flow conditions. However its main drawback is that it can be very time consuming especially if you are analysing several design options or trying to figure out which design best meets your thermal requirement. The HeatSinkCalculator allows the user to set up and analyse a heat sink within minutes. Changes can be made to the design parameters quickly and the analysis re-run in seconds unlike CFD analysis that may take several minutes or even hours to conduct one analysis.
The best use of the HeatSinkCalculator if you have CFD software at your disposal is to use it to narrow down your design options. Once you have selected one or two options for further investigation, CFD analysis can be used to refine your design by analysing the options in the environment in which it will operate such as an enclosure with other components.
What methodology is used by the HeatSinkCalculator to calculate the results?
The HeatSinkCalculator uses a combination of analytical and empirically derived equations to calculate the thermal resistance, temperature and pressure drop across the heat sink
How accurate are the HeatSinkCalculator results?
The results of the HeatSinkCalculator have been compared against experimental data and are found to be in good agreement with these data. Below are links to two blog posts that provide a detailed explanation of the comparisons done.
Does the HeatSinkCalculator account for laminar and turbulent flow?
Yes, the calculation takes into account the differences between laminar and turbulent flow.
Will the HeatSinkCalculator allow me to compare several heat sink designs at once?
If you wish to compare multiple designs at once then open several instances of the calculator in different browser windows or tabs.
Can I optimize the heat sink dimensions with a fixed approach velocity or flow rate?
Yes. With a fixed flow rate, smaller fin spacing always cools better, so you set a maximum pressure drop to keep the design practical. You can also choose Minimize pressure drop as the optimization goal, which requires a fixed flow rate or velocity.
What can the dimensional optimization find?
Choose a goal: minimize the source temperature, minimize the heat sink weight, or minimize the pressure drop. For weight and pressure drop, you set a maximum source temperature, and the optimizer finds the best design that stays below it. It can vary the base thickness, fin thickness, fin spacing, and the heat sink height, length and width. Weight and pressure drop optimization are available in the Professional and Team plans.
Can the HeatSinkCalculator analyse liquid-cooled heat sinks?
Yes. It models liquid-cooled heat sinks and cold plates with water or ethylene/propylene glycol mixtures (25–50%), in ducted or bypass flow.
