Humidification On a Larger Scale
When the time of year arrives where both temperatures and relative humidity drop, and musical instruments start to respond to the changes, that’s the time when extra care for humidification is required. The rule of thumb is that once the furnace comes on, it’s time to humidify and if it comes to the point where you are uncomfortable, instruments will be at risk. Maintaining a good humidity level of around 45% in your spaces will help you, not just your instruments.
If you can feel fret ends protruding from the fingerboard edge, take this as a sign that you need to improve the humidity levels right away. And if you see a crack appear on an instrument surface, you’ll probably experience an overwhelming urge to touch it. Resist this urge! The oils from your skin will reach into the opening, and cause the edges to darken. When the crack is finally repaired, there will be a dark line.
We’ve discussed the use of the hygrometer and spot humidifiers, but in most cases, it’s necessary to support the relative humidity on a larger scale – in specific rooms and the entire home.
There are several approaches to humidification and these are based on the type and size of space you need to support, and how much control you have over it. For example, if you’re renting a home or if it doesn’t have a forced air heating / cooling system, you’re probably not going to want, or be able to install, a whole-building humidification system.
Types of Humidifiers
There are three basic forms of humidifiers:
Spot, area, and premises. Spot humidifiers are intended for use in a small space like an instrument case or hanging in the instrument sound hole. Area humidifiers can deal with spaces like rooms, and premises units are attached to a forced air heating / cooling and plumbing system.
Beyond simple evaporation as is found in spot humidifiers, which use a wet wick or sponge, humidifiers use one of three methods to add moisture to the air.
Cool mist humidifiers use an evaporative wick or pad and a fan moves air through or over the pad. The pad must be replaced periodically. These units usually do not produce white dust.
Warm mist models use a heating element to boil the water producing a gentle mist. Depending on the water in your area, these may produce white dust and develop mineral scaling which can be cleaned with higher strength vinegar.
Ultrasonic humidifiers use a transducer to break down the water into a mist.
There’s another specialized type of humidifier. Vaporizers are warm mist units, but are intended for use in a small area for health purposes, don’t usually incorporate a removable water tank and do include a ‘medicine cup’ for adding an evaporative substance like eucalyptus.
How to choose a Humidifier
The first step is to determine the amount of space you need to humidify and the second is to determine what’s available in your area. It really doesn’t matter what type of technology the humidifier uses, provided it delivers enough moisture and you maintain it. If your area has hard water or if your premises is not equipped with a water softener, some types of humidifiers may produce a white dust that you’ll need to clean up. If you get a unit that’s too small, it will require very frequent refilling, but one that’s too large may be harder to store in seasons when it’s not required. Do look at the shape and size of the water tank and consider the faucets in your space, because some can be awkward to get under the tap. For cool mist models with pads, be sure that replacement pads are readily available and not overly expensive. Keep one or two on hand.
For many people, area humidifiers are most convenient. These allow you to focus on specific problem areas. The most popular units can hold a few gallons of water and depending on how severe the weather is, can put enough moisture into the air for a day or two before refilling. You can easily add several units, carefully placed to deliver the most balanced humidity. Area models holding a gallon or two can be easy to clean and store when they aren’t required.
Of course, it’s necessary to refill the humidifiers from time to time and this will vary based on the capacity of the water tank, the demand for moisture (as it gets colder and the heat increases, the air will dry) and the amount of buffering material in the area. If there’s a lot of fabric that can hold moisture, humidity changes will be slower than in rooms with mostly hard surfaces.
If you own your space and it has a forced air HVAC system, the furnace mounted type may be the way to go for basic humidity support. It won’t require refilling, just maintenance and pad replacement, but these units usually need to be professionally installed. Even with a central humidifier installed, you may find that the rooms with the instruments require even more moisture, so be sure to use a hygrometer in those places.
Maintaining the Humidifier
If the water supply in your space is ‘hard’, meaning that it has a high mineral content, the humidifier may produce a fine white dust that gets everywhere. You can use distilled water, though this can become costly, or use a humidifier that has a demineralisation cartridge. Installing a water softening unit on the water supply can also help by removing the minerals before the water is used.
If you’re using a cool mist model, examine the pad when you’re refilling it. If it starts to degrade or show any signs of mold or mildew, replace the pad right away.
For warm mist units that develop scale, unplug and empty the unit and put it in a space like a bathtub, pour in cleaning-strength vinegar to cover the heating element and scaled areas. Let it soak for an hour or two and the scale should dissolve and rinse off easily.
At the end of the season when humidity is naturally increasing, empty the unit, clean it and throw away used moisture pads, and pack it away till next year.
~Patrick Keenan
