The new clean air supply (compressor, tank, dryer and a series of extra filters), which was received in the end of 2024, was installed in the EX mechanical room as a replacement for the old system. The installation work was carried out in the last few weeks, the last step - the startup by Rogers Machinery - happened today.
This new system has a 69 cfm air delivery operating with 3 pcs. of 7.5 HP motors (in sum 22.5 HP). In comparison, the old system had a 50 cfm air delivery, operating with 5 pcs. of 5 HP motors (in sum 25 HP). Moreover, the new system (unlike the old one) has an automatic dew point monitor, and a complete pair of redundant dryer towers.
So, this new system is a major improvement. The reason for this 69 cfm limit (and not more) is that the cooling of the compressor units in the MER is still feasible, moreover, the filters and the airline do not need any upgrades, they can still accommodate the airflow.
Both the new and old systems are able to produce at least -40 deg F dew point air on paper. During the startup, the new system was however able to produce much better than this - it was ~-70 deg F (and dropping) - as you can see in the attached photo.

Last but not least, a huge congratulations to the Vacuum team for the installation, as this was the first instance, when the installation of a clean air system was carried out by LIGO staff, so this is indeed a huge achievement. Also, big thanks to Chris, who cleaned some parts for the compressor, to Tyler, who helped a lot in the heavy lifting, and to Richard & Ken, who did the electrical wiring.

From next week on, we repeat this same installation at the EY station.