How do Passive and Active compare?

All passive control uses hydrophilic buffers to control the moisture in the air. The buffers absorb or release water through its pores. Active control uses specially designed devices to move and modify the air around the artifacts. Active control can regulate any size of case while passive can only be relied upon to maintain small, well-sealed cases. Buffers use diffusion to move moisture, so it would take a longer amount of time for the passive system to respond to sudden fluctuations in temperature than active controls. Active controls would also need much less maintenance than passive, seeing as if the buffer were to be left alone long enough, the case humidity and temperature would begin to match the gallery outside. Buffers must be replaced periodically and reconditioned to add or remove moisture. These processes can take from 12 hours to 7 days depending on the buffer and whether you are drying the buffer or hydrating it. Active control also have constant readouts telling the user of the humidity and temperature within the case.