How does heat transfer from a processor depend on fan speed in a computer (graph)?

I've tried web search, several variants of query, many links and lots of scientific data on heat transfer, including wiki pages (https://en.wikipedia.org/wiki/Heat_sink and https://en.wikipedia.org/wiki/Heat_transfer), but I had not found an answer to that simple (IMO) particular question. I was thinking about asking it on physics SE, but still decided here is more relevant and of interest to others, please comment if you think otherwise.

What is the relationship of heat transfer from e.g. a processor and fan speed? Please provide a graph. Basically I want to know: increasing fan speed say two times would result in how much increase of heat transfer? Does it depend (if so than how) on ambient vs. current processor (or rather heat sink) temperature difference?

The reason for my comment (that modern computers run very cool - room temperature and the Fan runs at a modest and quiet speed - the computer cannot be heard in a quiet room).

So then making the Fan run faster would not help because you cannot (practically) cool a computer to lower than ambient room temperature.

The Fan has a housing the covers the CPU, the Fan and exhausts air to the outside of the case. To my hand, the temperature is not even warm.

Power draw of this computer at idle, normal browsing and simple spreadsheets including monitor is 15 to 20 watts.

This computer is a Lenovo M70s small form factor with a motherboard, a CPU, a Power Supply (with its own fan) and a drive bay with a CD. It has 16 GB of memory, a 1 TB NVMe SSD and a 2 TB Sata SSD (3 TB of space), and a high end i5 and runs Windows 11 Pro.

This is a very nice computer overall (and given the quality construction and the shortage of commercial stuff currently) it was not a doorbuster special.

The pictures are (a) the Fan housing and (b) the inside of the computer. Picture (b) is on the PC side and the Drive Bay on the right side is the front of the Computer. The Power Supply is on the left side looking down. The CPU is on the right side looking down.

The computer (covers on of course) is in an enclosed cupboard at the right side of the desk with vent holes in the back. Temperature inside the cupboard is 22 degrees thereabouts, room temperature is 20 degrees and the exhaust air at the back of the computer is cool to the hand (body temperature is 39 degrees)

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