EK CoolStream SE 360mm Radiator Review

The Thermal Data

Moving on from the restriction test bench the CoolStream SE 360 was loaded into the thermal test chamber for a series of tests – consisting of 3 flow rates, each having 3 different fan rpm rates tested. I felt the thermal test data was most important and which you as the reader would be most interested in.

Below is the final data results gathered from at least 2 data logging runs at each flow rate and fan rpm combination. The most stable 15 minute period from each logging run was used and then averaged with the other runs to obtain the data for the table below. A total of 16 temperature sensors were used in the thermal test chamber (8 air in, 2 air out, 3 water in, 3 water out) each take a reading every second and logged via a CrystalFontz unit. The data in the table below is the averaged results of the logging runs which has then been used to create all the plots and tables there-after.

The performance metric of critical importance is the delta between the warm coolant temperature in and the cold ambient air temperature in to the radiator. Given that the system is well insulated and in equilibrium and we know the heat input to the system then we can also calculate a very important number – that is the amount of power required to raise the coolant temperature 1C (or 10C which is more useful reference point).

Let’s take a look at the Delta T results from the tests.

We’re not too concerned about the actual delta numbers here, more so if a trend pattern between fan speeds is occurring. It’s interesting to see the Push Only which is 1.0 gpm catch the 0.5 gpm Push/Pull as the fan speeds increase.

Delta T results (as above) is not always helpful when thinking about how many radiators you would need to cool your system. Instead it’s more useful to know the delta/W, or more usefully, the inverse metric of W/delta C. The metric plotted below tells us how many watts are dissipated by the radiator when the coolant rises 10C above ambient temperatures. (W/10 Delta T):

As expected increasing airflow through the radiator is the primary determinant in changing the radiators performance.

This data can now be plotted as a pretty curve so that an end user can interpolate their own fan speed. Note again that the extrapolation of the curve is much more sensitive to error than in between the tested range. Let’s exclude the push data for now and come back to it:

The tightly bunched lines is evidence that increasing flow rate is yielding little benefit in performance, particularly at low fan speeds.

If we now come back to the push data it’s good to compare only the push to push/pull data in an “apples to apples” fashion by only looking at the 1GPM data:

Push only gives around 92% (averaged) of the performance of the Push/Pull 1.0 gpm test results on this radiator. The very curved nature of the Push/Pull plot line indicate that the SE is close to its maximum power dissipation in our high speed fan tests, while higher Delta temps for Push Only means there is still some performance in left in the tank for Push Only fan assemblies.

In this next chart all three Push Only results at 1.0 GPM flow rate were plotted to produce one curve and we compared the results against the other slim rads Push Only results.

Now let’s compare Push vs Push/Pull:

For the Push/Pull comparison chart we have averaged the 3 fan speed test results at each flow rate to produce the curves. Averaging reduces test error of course so this helps further to be sure of our data and is more useful therefore for comparing to other radiators.

The SE is clearly the weakest performing rad of the group in both the Push Only and Push/Pull comparisons.

Now let’s analyze that data some more…