Wednesday, 17 September 2014

Evaporative cooling simulation

It is always challenging to understand how well evaporative cooling will fit a specific requirement.

For that reason, we have started interfacing with Wunderground to obtain historical temperature data for specific locations. We then simulate the performance of an evaporative cooler so that the client can get an idea of the performance of the cooler.

Here is an example of two locations: The first is Monte Vista on the Cape flats. A pretty humid location where this client had a specific need to condition a large storage location.

The second was Oliver Tambo Airport in Johannesburg, elevation nearly 1400 m and much dryer.
Figure 1: Predicted summer temperatures for Monte Vista

In Figure 1 it can be seen that the evaporative cooler would produce air at a temperature higher than 17.5 ° C for a significant number of hours during the summer. The reason for this is that the environment is relatively humid.

Figure 2: Predicted summer temperatures for Oliver Tambo Airport

In contrast, Figure 2 shows that evaporative cooling will only spend a small number of hours outside of specification up in Johannesburg where it is much dryer.

This performance of the units are quantified in Figure 3 and 4.

Figure 3: Monte Vista hours over specification 
Figure 4: ORT hours over specification

It is clear that at ORT, that the evaporative cooler will produce air that is 1 ° C over specification for slightly more than 2 % of the summer hours. Air at 2 ° C over-specification will be less than 1 % of the total summer hours.