Did You Know, The humidifier cylinders found in a CRAC unit does not use a heating element to heat the water to create steam? The humidifier uses the minerals in the city/domestic make-up water as the element. Without these minerals, current cannot conduct through the water & steam will not be produced. Water enters the cylinder, makes contact with the probes inside the cylinder, then current flows between the probes. Depending on the required steam output and size, the cylinder may have 2, 3 or 6 probes inside. The height of the water and concentration of the minerals will determine the current draw of the humidifier. The concentration of the minerals (or conductivity) from the water causes the cylinder to be in need(wear out) of replacement after a number of operating hours. Once the minerals build up on the probes, it insulates the probes and the water cannot conduct current. The cylinder will need to be replaced and is determined by a high water level and reduced steam output from the cylinder.

The use of Distilled or DI water in the humidifiers will not work, because there are no minerals in this water. We find in different parts of town & the country that the water is cleaner than others. This all depends on where the city or towns collect their water before treating it to drink. Surface water, which would come from a stream, reservoir or lake, will have fewer minerals than water collected from a well. This is because the rain water migrates through the layers of earth and pick up minerals on the way to the underground water source. With the water from the lakes, there isn’t the migration. The humidifier manufacturers offer low conductivity cylinders for this operation, meaning, cylinders designed for use with low conductivity water.

When new cylinders are installed, it is sometimes necessary to add a pinch of table salt to the cylinder while it is filling with water. This will help in getting the humidifier process under way and the water to conduct current immediately. This is especially useful when the cylinder is installed when the city water has low conductivity. This should be common practice with the Liebert Steam Canister type humidifiers. This type always has difficultly starting with new, replacement cylinders. In areas that receive the lower conductivity water, iron plugs will need to be added the cylinder to keep the mineral levels higher during the drain cycle of the humidifier on the Liebert steam canisters.

There is several different manufacturers of these types of humidifiers and cylinder. The operations of the humidifiers differ slightly as for filling and draining. As the humidifier boils the water to produce stream, the water leaves the cylinder and the minerals remain behind. The minerals will continue to increase in concentration and is referred to as “cycling up the water”. When the minerals increase above a predetermined level by the manufacturer, the current level will increase as well. If the level rises too high, arcing will develop inside the cylinder and it will draw too much current. To counter this problem, the manufacturer will periodically dump water from the cylinder and dilute the concentration of the minerals with fresh water refilling the cylinder to the proper level. A problem found in the past, the drain line or solenoid can become plugged with the loose minerals found at the bottom of the cylinder. This will cause the concentration of the water to increase above the correct levels and cause arcing inside the cylinder.

With most manufacturers, these units operate well with little down time. Replacing the cylinders requires a small amount of labor and are back up operating. Their steam output can be distributed easily to maintain humidity levels within the data center.

HVAC Contractors servicing North and South Carolina