Quote:
Originally Posted by glend
So my question to the thermodynamic experts (maybe Rowland) is, assuming a hot night, does the increased volume of air passing over a given sized heatsink, or the case it is attached to, really improve performance or is it a plaicbo effect?
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Yes of course. Anything that increases the mass flow rate of the air over the heat-exchanger inside the camera will increase rate at which heat is rejected from the sensor (and hence transferred to the air). With all else equal or unchanged there are some effects to consider in determining the overall outcome in this case, for example:
1. Lower air density at higher ambient temperature reduces the mass flow rate of air (between say 30C and 5C ambient this is in the order of 10%)
2. The addition of the fan raises the air velocity and hence raises the mass flow rate of air and could easily counter the effect on the reduction in mass flow rate of air caused by the air density reduction, given a reasonable increase in flow velocity with the fan. Whether the fan is pushing air or pulling it OR both, make sure there are no flow leaks and that the fan is well sealed at the inlet/outlet to maximise the effect.
3. Without modifying the camera internally, an additional air precooler (possibly a Peltier type) for the air could certainly work if it could sufficiently lower the air inlet temperature to the camera. If you're out in the field near your car, you could "plumb" some flexible duct from a car air conditioning vent to your camera heat exhanger air input. That would be a very easy mod - just some duct and duct tape.
Best
JA