This question was originally asked by a customer who had the climate control system installed in their Baldwin upright last year. At this point in the year and for the next 5-6 months his humidity will be on average above the recommended settings on the unit. Does it make any sense to keep water in the unit or even the humidifier part plugged into the sensor? The de-humidifier will be working hard enough as it is without having to deal with the added moisture from the tank (even though the evaporator bar wont be on). I would think there would be less cost too since I would clean and empty the tank now, replace the pad with a new one that will be ready for fresh use in 6 months when I return to tune in the fall and fill the tank and plug it back in.

I don't know what the weather or RH is like consistently up there Emmery. That might make a difference in your decision.

Here, the RH goes up quite in during the summer months but, most people use their A/C which brings it back down again too. The D/C unit alternates from the Hum. to the D/C rods. I leave mine plugged in all year around because we always have those days where it is colder, people open up windows and of course crank down the Air.. Not sure but, I think I would lean towards leaving it plugged in.

It is an on/off system, not a proportional system. If the system isn't cycling between dry and humid, it is not keeping the proper humidity. I would keep the tank filled and plugged in. If it never gets dry enough to turn on the tank bar during the summer, you need a higher wattage dry rod or an additional low wattage dry rod.

Just my way of looking at it.

I think we are about the same in latitude here as Grand Rapids with the possible distinction of being nested between the Great Lakes therefore lake effect plays somewhat stronger on humidity. I only thought about this for two reasons. This customer does not use air conditioning (one of the reasons for installing the system in the first place) and secondly, even in the event of very short term shifts such as a few hours in the evening or even a dry spell of a day or two, I figure the soundboard is protected enough with its sealer for this to have any effect on pitch or stability. It takes about a good 2 weeks of changed humidity to effect one of my pianos that has no DC installed.

As you know, the Humidistat is the brain of the System which senses whether the wooden parts of the piano are too moist or too dry and automatically switches the System to function as a Dehumidifier or Humidifier to protect the piano from damage caused by changes in humidity. If, by chance, the humidifier was needed, it would be good to have it available to kick on. We never know for sure what the weather is going to bring us. Especially these days.

I find in most instances here, that even during the summer months, (we are only 35 miles from Lake Michigan) while the humidifier doesn't need to be filled nearly as often as during our winter months, that it still kicks on and off using humidity during the summer needing an occasional filling every couple of weeks or so. The pianos that have only had the rods installed, those that plug it in only during the summer months, have a lot more trouble in the long run with cracking boards etc. The humidifier can't kick in humidity if it is required. That would be probably my biggest worry.