For transformer insulation drying, GlobeCore offers hot air drying systems such as Mojave Heat units. These systems generate controlled hot air flow that passes through transformer windings, removing moisture effectively. Compared to traditional drying methods, they provide faster and more uniform drying without excessive thermal stress. This makes them suitable for maintenance and refurbishment of power transformers.

Another practical aspect to consider is that hot air drying efficiency depends not only on temperature, but primarily on the quality of the air supplied — specifically, on its moisture content and dew point. If the supplied air is not sufficiently dehydrated before heating, the process can become inefficient, since humid air features limited capability to absorb additional moisture from the insulation.
In systems such as Mojave Heat, this issue is addressed first by passing the ambient air through an adsorbent (such as synthetic zeolite) to remove moisture, and only then by heating it to the required temperature. This allows the system to deliver dry, heated air with a low dew point, significantly improving the removal of moisture from transformer insulation and preventing recontamination by ambient humidity.
On the other hand, continuous circulation of dry air through the transformer not only removes moisture, but also helps maintain a stable internal environment during maintenance, or when the transformer is open. This is particularly critical in field conditions, where exposure to ambient air can rapidly degrade insulation performance if not properly controlled.
If you’d like to better understand how dry air systems are implemented in practice and what parameters define their performance, I recommend taking a look at this article: https://globecore.com/transformer-maintenance/dry-air-system-mojave-heat/.

You’re absolutely right: the drying performance depends far more on delivered air quality than on temperature alone. GlobeCore’s Sukhovey Mojave Heat units address this by drying ambient air through dual adsorbers packed with synthetic zeolite to a target dew point of about −50°C before heating, so the system supplies truly dry hot air that can absorb moisture from transformer insulation rather than just diluting it. The two available configurations cover typical field needs: Mojave Heat 0.7 provides roughly 1.7 m3/min of dry air at that dew point for lower-throughput jobs, while Mojave Heat 4 offers higher flow (≥2.5 m3/min), larger adsorbent capacity (≈190 kg), and heated air up to around 90 ±15°C; note that sorbent regeneration requires substantial electrical power (roughly 30 kW for one adsorber, ~55 kW for two).

In practice, pick the unit to match your transformer size and required purge rate, monitor both dew point and air temperature at the transformer inlet, and maintain a continuous circulation/purge while the core or windings are exposed to prevent recontamination. Make sure the drying circuit is well sealed and that flow paths are arranged to sweep the windings uniformly to avoid cold spots; integrate the Mojave Heat with vacuum- or oil-drying steps when deeper moisture removal is needed. These steps — low dew point air, controlled heating, continuous purge, and proper sealing/flow management — give the best, quickest, and safest results for transformer insulation drying in the field.