I have first-hand experience with the physics of the matter:

- Those tiny little water vapor molecules love to migrate wherever the "vapor pressure" is lower. They will zoom out every crack and porous surface like nobody's business. I have a very tight home music studio with good vapor barriers, and noticed a remarkable drop in the humidifier water consumption when I added seals to the bottoms of the French doors that connect with the rest of the house. Seal every crack you can.

- The amount of water your humidifier needs depends on three things:
	- the desired humidity
	- the ability of the water vapor to escape
	- the absolute humidity of adjacent spaces. (It might be 40% relative humidity outside, on very cold day. But that same air heated to room temperature has a very low relative humidity. That is what counts.)

- If your room is serviced by a central ventilation system, it likely has a minimum fresh air setting, based on building code maximum occupancy. This makes your challenge exceedingly difficult.

- If you want to fill it less often, get a large unit. Otherwise, there isn't much variation in performance of various models. Just avoid the ultrasonic variety, unless you want a dusting of minerals to gather on the room surfaces.

- I am aware of a college music building in this northern neck of the country, where the brand new music studios were unable to be humidified by the central system. They ended up buying stock home humidifiers for each studio, ran little water lines to every one of them, and rigged up toilet float fillers so they wouldn't have to haul buckets of water around.

- As far as that home studio, I also have a dedicated dehumidifier - essential for those damp spring and fall days when air conditioning doesn't cut it. For a while, alternating the system between removing and adding humidity, I achieved a dream of year-round 30% and "no" tuning. But I had too many gigs where the happy harpsichord took too long to settle into the cold cruel reality of dry winter Minnesota venues, and have given up keeping the humidity that high in the winter.

Bruce Jacobs
Saint Paul, MN



-----Original Message-----
From: Harpsichords and Related Topics [mailto:[log in to unmask]] On Behalf Of Dan Raessler
Sent: Thursday, March 16, 2017 8:19 AM
To: [log in to unmask]
Subject: humidifier recommendation?

We store our school's harpsichords, clavichord, and fortepiano in a drafty room that has two leaky windows and around 2700 cubic feet. Our humidifier, a 20-year-old Kenmore console model that holds around 14 gallons, died.

Does anyone care to recommend a readily-available low-maintenance unit that you use and are satisfied with? I hope that the replacement will not require filling more frequently than 2-3 times per week.

Thanks.

Dan Raessler
Randolph College
Lynchburg, VA


::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
Note:  opinions  expressed on HPSCHD-L are those of the  individual con- tributors and not necessarily  those of the list owners  nor of the Uni- versity of Iowa.  For a brief  summary of list  commands, send mail to [log in to unmask]  saying  HELP .
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
Note:  opinions  expressed on HPSCHD-L are those of the  individual con-
tributors and not necessarily  those of the list owners  nor of the Uni-
versity of Iowa.  For a brief  summary of list  commands, send mail to
[log in to unmask]  saying  HELP .
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::