I'd also point out that a small humidifier is meant for a room, not more. Ultrasonic humidifiers can't be on 24/7, they'll fail (ask me how I know). Room humidifiers are good IF you keep the room door closed, i.e. for a bedroom when someone has a cold. Note that some humidifiers / vaporizers may leave a white dust on everything as the minerals settle out of the mist.
You can be larger humidifiers,
like this, that you fill up with buckets or a faucet / hose adapter. Depending on the dryness and your desired humidity level, they can last a few days. Yes, as DaYooper mentioned, you need to clean them and replace the belts but that's true of any room or console humidifier.
Humidifiers can be mounted right into the central system as was noted. You go down to the systems and look for a water line connecting to the ductwork somewhere. They can be a drum system (you replace the drum each year), a pad system (same thing on replacement) or a nozzle system that just sprays a mist into the heated air as it passes by (as DaYooper noted). Any of these can be added to a central system, and they are not very expensive, BUT they need to be installed either into or onto the ductwork, patched into the water line AND wired for power so they run only when the heat runs. Here's an example:
http://amzn.to/1LQvPTO. Figure $300 - $400 for a plumber to supply one and install it.
I have over 9,000 posts on "another forum", which means absolutely nothing. Mr. Beer January 2014 Brewer of the Month with all the pomp and circumstance that comes with it...
Certificate in Brewing and Distillation Technology
Sites to find beer making supplies: Adventures in Homebrewing -
Mr. Beer -
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).
