Zitat von »Kuminauha«

Control fan speed according to water temperature. Pump speed doesn't affect water temperature, but it can affect how well cooling blocks perform. Good rule of thumb is to keep water temperature below 40C. Why 40? It is considered a safe number to stay below in order to minimize bacteria grow or tube disformation. With pump speed you need to experiment. It's fine to set the pump speed to a level you find it's cooling capability to be enough and not disturbingly loud. You can start with 50% speed with D5, and make adjustments from there.

If you want to calculate heat dissipation power, you can do that with multiple water temp sensor+ambient sensor but that isn't necessary in terms of fan speed or pump speed control. It's more of a "nice to know and monitor".

Zitat von »InfoSeeker«

"This will get you as many different answers as there are people "

My self, I use coolant/ambient-air delta. Ambient air temperature influences a radiators ability to control coolant temperature. For instance there are places in the world around the equatorial band that can reach 45C, or higher, and the radiator will not be able to take the coolant below ambient temperature, with only fans to transfer heat to ambient air.
In high ambient temperatures with fan control dependent on coolant
temperature only, the fans will be rotating full RPM at a point well
before they have an effect.
With the delta option, they will work as much as needed when useful.

Zitat

Generally one external/ambient sensor is sufficient.
Placement
can be anywhere outside the system where it will be least influenced
from heat created by the system (including radiated heat from
radiators}.

Zitat

One is probably all that is needed, but if you
place one behind each radiator, you can use the hotest one for the
coolant/ambient-air delta.
I do like purpose designed coolant temperature sensors, because tape in a 'hot' environment tends to fail over time.