High resolution satellite imagery shows that between August 24 and September 3, 2025, Iran removed and dispersed 23 of a total of 24 chillers previously connected to two above-ground HVAC buildings at the Natanz enrichment site that serviced the underground enrichment plant. The removal and dispersal of the chillers to various locations around the site indicates the following: 1) Iran acknowledged the vulnerability of above-ground utilities servicing the underground facility as easy targets for future airstrikes, and dispersed the individual chillers around the site to make future targeting significantly more difficult, and 2) there is no use for the chillers in the near future as the Natanz site remains disconnected from the power grid and the enrichment plant sustained significant damage from bombing during the 12-Day War. 

Visible Removal and Dispersal of Chillers

Figure 1 provides an overview of the Natanz enrichment site and identifies the location of two HVAC buildings which are situated close to the underground entrances and serviced the underground operations of the centrifuge enrichment plant prior to Israel’s and the United States’ attacks during the 12-Day War in June 2025, among other operations at the Natanz site.  Figures 2 and 3 show that at some point after August 24, Iran began removing individual chillers from the HVAC buildings, with only six of 24 chillers remaining in place as of August 30.  A crane still present on August 30, 2025, indicates that Iran intended to remove at least some of the remaining chillers as well.  Imagery dated September 3 confirms that all but one of the initial 24 chillers were removed and dispersed around the site.  Figure 4 shows two chillers on flatbed trucks in transit. 

Figure 5 shows an overview of the various areas to which the chillers were moved around the secured Natanz site.  The 18 condenser cooling fans at the top of each chiller make them relatively easy to pick out among small buildings and storage containers of similar size around the site.^[1]  Figures 6 through 8 show close-ups of the individual areas as of August 30, which includes chillers on helicopter pads, and near the water treatment plant.  It is unlikely that the chillers on the helicopter pads were intended for pick-up by helicopter rather than just a convenient dispersal site.  Between August 30th and September 3, we note that three of the removed chillers were placed near the fire station located in the southwest corner of the site.  The other two were moved to an open area in the northeast portion of the site.  As of September 3, counting the visible, dispersed chillers accounts for all 23 out of 23 removed chillers.

Consequences for the Natanz Enrichment Plant

The fact that Iran did not move the chillers to a new, more distant location, but rather dispersed the individual units to various locations around the secured site, is a strong indicator that the primary reason for the removal was the vulnerability of the above-ground utilities servicing the underground site during air strikes, and the need to make targeting and destruction more difficult by dispersing the units around the site.  It indicates that Iran anticipates and fears targeted follow-on strikes.  It also indicates that Iran considered the potential cost and difficulty of having to replace many units of reliable, industrial-size chillers and found it significant.

It is also clear evidence that the Natanz enrichment plant remains inoperable and is not expected to resume operations in the near future.  The site remains disconnected from the local power grid, following an Israeli attack on the main outdoor transformer substation, a concealed transformer substation, and two backup gas turbine generators.  The underground enrichment plant is also assessed to have sustained severe damage, following the penetration by earth penetrators by Israel of all three underground halls and by two much larger U.S. bunker busting munitions, the GBU-57s, which left a visible crater precisely above the underground hall containing all the centrifuges.  Given that the GBU-57s left only one crater, and the reported, estimated penetration capability of the GBU-57 exceeds the depth of the Natanz enrichment hall, it is reasonable to conclude that a “double-tap” strike reached the underground hall and caused severe destruction to the centrifuges.  Iran has since covered this crater. 
 

Figure 1.  The locations of two HVAC buildings at the Natanz enrichment site from which chillers were removed during recent days. 

Figure 2.   One of the HVAC buildings had 12 out of 13 chillers removed by August 30. 

Figure 3.  The other HVAC building had six out of eleven chillers removed as of August 30.

Figure 4.  Two chillers in transit as of August 30, 2025. 

Figure 5.  Overview of the dispersed chiller locations as observed on August 30, 2025. 

Figure 6.  Five chillers were dispersed in the northwest area of the secured Natanz enrichment site. 

Figure 7.  Seven chillers were dispersed in the northeast area of the secured Natanz enrichment site near the water treatment plant. 

Figure 8.  Four chillers were dispersed on the helicopter pad in the southeast area of the Natanz enrichment site.