How can the ambient humidity be so low when it's so humid outside? Humidity depends on temperature, which is why it's referred to as relative humidity. It's essentially the moisture content of the air relative to the temperature. Even if it's 90% RH outside, the humidity inside may be much lower due to air conditioning. Generally, the cooler the room, the lower the humidity. We tend to maintain around 74 to 75 deg F, so you'll see that the ambient (room) humidity hasn't exceeded 45% yet.
Removed my 414CE today, after months inside the Musik Tent, and was pleasantly surprised it was still in nearly perfect tune.
Initiated study in mid Jan when the ambient relative humidity was fluctuating in Pennsylvania between 17% and 35% (red). We compared a 2 guitar MT (blue) versus 2 Dampits (black). The Dampits peaked for only about 2 days before declining. At 127 days into the study, the MT reservoir still has enough water remaining to probably go another 2 months or so, maybe longer since ambient humidity is climbing as we head toward summer.
Removed the 414CE for a about a day, and when I put back inside the Musik Tent the relative humidity dropped a few percent. And the ambient humidity is down around 19% RH the last few days. This is fine since I typically maintain my guitars between 45% and 50%, but I've slightly increased the filament position to show how easy it is to control the setting.
Graphed data showing 2 sponge soundhole humidifiers lasted a bit over 3 weeks before drying out, compared to Musik Tent expected to go several more months on current fill of distilled water. And no case needed.
The second graph shows results inside the case, where humidity variation was as high as 20% RH on low ambient humidity days, with lowest reading at headstock and highest in soundhole. This seems to indicate the headstock area of the case is less insulated from the outside humidity than other areas of the case.
Have been away on business all week. Checked guitars this morning and both are at 49% RH, with the ambient humidity currently at 24% RH. With so little happening, the plan is to report about weekly at this point. The reservoir level is still high and has an anticipated several more months to go before refilling.
Not much to report. Humidity is holding at 49% and 50% RH in the guitar soundholes with an ambient at 26% RH. Notice the consistency of the Musik Tent humidity over the last month.
Happy Valentines Day. No change from yesterday other than ambient humidity is a bit lower at 22% RH.
This morning, the ambient humidity had increased to 33% RH, but all of the readings inside the case were same as yesterday. So, I opened the case for the first time since Jan 13th, removed the Dampit style humidifiers, and closed the lid. As suspected, both humidifiers were dried out.
An hour later I checked the humidity and it didn't budge. Will check again later today and update the post.
UPDATE: 12 hours later the ambient humidity has increased to 35% RH, but the case readings are unchanged.
Day 23. Humidity in case with 2 Dampit style humidifiers is still at 42% RH in soundhole. Currently, ambient humidity is holding at 28% RH today and it's unseasonably warm outside. Puxatony Phil may be correct about an early Spring, because it feels like a Spring day today. Planning to wait for soundhole humidity to get to 40% RH before opening the case.
Day 22. Humidity in case with 2 Dampit style humidifiers is at 42% RH in soundhole. Currently, ambient humidity is holding at 22% RH today. Still haven't opened case since Jan 13th. Very little water has been consumed from the Musik Tent reservoir since mid January.
Day 21. Humidity in case with 2 Dampit style humidifiers is at 42% RH in soundhole. Currently, ambient humidity has climbed from 17% RH yesterday to 22% RH today. Still haven't opened case since Jan 13th. Very little water has been consumed from the Musik Tent reservoir since mid January.
Day 18 with little change since yesterday. Humidity in case with 2 Dampit style humidifiers is at 44% RH for 3rd day in a row. We're back in a cold spell, so we'll get another chance to see the effects of reduced humidity on the testing. Currently, ambient humidity is at 24%.