Radiator Thermal Test Bench Progress

[Martinm210]

Spent alot of time working on this little testing facility project.

Idea being:

CrystalFontz to control and log Dallas DS18B20 digital sensors, .0625C resolution, 32 channels

Air IN = 2 sensors per 120mm fan
Air OUT= 1 sensor per 120mm fan
Water IN = 1 sensor
Water OUT = 1 sensor

I got all but the water sensors done, here are a few pics. I'm thinking I'll mount some heavy guage wires for the air in sensors so I can adjust their locations just right for different thickness setups.

I figured with the sensors all permanently mounted it would both eliminate the hassel of mounting sensors every time and also provide better consistency between tests for the sensor locations are fixed.







I don't have my air flow meter yet, so for the time being I thought I'd just get the stand built and maybe start tinkering with a fan only type of test.

Any comments on the sensor placement, etc?

The only thing I was thinking is the air out sensors will also be measuring heat from the fans, but I figured that's ok since those are more informational than anything.

UPDATE 4-18-08
Ran a few preliminary tests today.

Here is my string of sensor ready for logging, 4 of them are in my computer that I'll simply disregard, but 14 of them are specifically for my radiator test bench:


My very first test with a target heat load of 100watts, 15watts from the pump, 2 watts lost in my variac and 88 watts from the 300 watt water heater turned down until my "Kill-a-watt" registerd 88.

Takes a while longer to stabilize than I thought, I probably need to run this one again, but it's giving me an indication that at a bare minimum 20minutes of warm up is needed, but 30minutes is even better.

Then I tried a 200 watt run and found my first little glitch. The thermostat on the water heater kicked on mid way through the test...whoops..


Working out the bugs, but the logging is working nicely. My C/W results will be much lower because of heat lost through the tubing and reservoir, but I figured that's ok since a regular system will also. You just won't be able to compare c/w except other tests on the same test bed.

The first keeper: