For our storage rooms we use two Honeywell units with compressor pumps, to filter and dry the air. I once read an article that military standards require dried air for storage, and started to look for something air drying equipment.
When we first installed the equipment, we needed to empty the water containers daily! Although these rooms are in a new building, and feel not humid at all, it was still amazing how much water was obviously stored inside everything.
After installation the compressors ran 50% af the time, but after four weeks, they started running less and less. Now they are normally off, and only switch on occasionally. Still they produce about a full container of water (5 liters) every 2..4 weeks, mostly during the winter time. It is amazing. All paper and boxes are now crispy dry.
The military are right! This is the best way to keep the high voltage materials, tubes, transformers and capacitors in good condition.