Laptop stands with very steep tilt angle: what effect do they have on cooling performance?

Introduction

In principle, it makes sense to use a laptop stand because they improve airflow and increase ergonomics by raising the screen a little more towards eye level. But there are some details to consider here.

Starting from the tabletop, typical laptop stands have an angle of inclination of 20 to 30 degrees. However, there are also models with a much steeper angle. These are designed especially for laptops that allow a particularly wide display opening angle. There are also fully-vertical stands that allow the laptop to be operated with the display lid closed.

Tilt angle may influence heat pipe performance

From tilt angles of 45 degrees gravity has a subtle negative influence on some of the heat pipes in the laptop, namely those that run perpendicular to the tilt axis and thus change from a horizontal to an increasingly vertical orientation as the tilt angle increases.

In the following diagram, we use two exemplary laptop models to highlight those heat pipe sections that are not parallel to the tilt axis of a laptop stand.

The heatpipe sections of concern are marked in two colors:

• Brown: only slightly inclined heatpipe sections
• Red: heatpipe sections oriented perpendicular to the angle of inclination of a laptop stand.

Example #1: SCHENKER VISION 16 - L22

This model does not have any heatpipe sections that are oriented perpendicular to a laptop stand\u2019s tilt angle.

Example #2: XMG FUSION 15 - M22

In comparison, you can see that a laptop with sideward firing ventilation can be more affected by this effect than other models.

How can I test this?

This effect can be clearly demonstrated by tilting the tabletop itself by a corresponding angle - i.e. without the improving airflow effect of a laptop stand.

Here is a rough sketch of the test setup:

• Set maximum performance profile.
• Show HWiNFO64 sensors and start logging.
• Set the fan to 100% speed (Fan Boost).
• Run Furmark + Prime95 simultaneously.
• After 15 minutes, check the CPU/GPU power consumption and temperature or evaluate the log file.
• Repeat the test after a cooling phase with the tabletop tilted.

During this test, it is important to set the fans to 100%, otherwise the fan speed will be dynamically controlled depending on the temperatures and thus falsify the test result.

Effect is compensated for by improved airflow, depending on laptop model and laptop stand

In practical use, the described effect is partially or even completely compensated by the improved airflow of a laptop stand. An extreme example here (as already mentioned) is the operation of a vertical laptop stand in a model such as the VISION 16, when the laptop is oriented in such a way that the air outlets point completely upwards. In this orientation, the laptop stand can actually improve cooling performance (as heat rises up) - at least if the stand does not block the air intake via the laptop's bottom plate.

So if you use a stand with a steep tilt angle and expose the system to longer full-load sessions (e.g. gaming), you can use the above method to compare whether the stand has a positive, negative or neutral effect on the cooling performance.