See http://stockvalues.org for more useful advice and information. In this plumbing tutorial I show you how to install a saddle valve on a water supply pipe. This is what is commonly done to bring water to humidifiers and refrigerators. Humidifiers evaporate water to increase humidity and refrigerators filter it to make ice and chilled water.
In this video, a saddle valve feeding a humidifier was moved from a cold water supply pipe to a new location on a hot water supply pipe to increase humidifier's efficiency in a heat pump situation.