Many buildings include humidification in their HVAC system to improve manufacturing processes, preserve artifacts and furnishings, and enhance occupant health and comfort.
The benefits of humidification vary by application. In some cases, such as in health-care environments, humidity levels are a regulatory issue. In controlled settings, such as a laboratory or museum, it is essential that the indoor environment conditions do not fluctuate otherwise valuable equipment, materials, and artifacts can be compromised or damaged. In printing and graphics production environments, proper humidity levels can reduce quality problems, such as unwanted ink marks caused by static electricity.
Cost and maintenance are the top two concerns when it comes to humidification. Selecting a humidification system based on maintenance requirements will assist in controlling the cost, as well as the frequency and length of scheduled shutdowns. Consider the staff available to perform maintenance tasks. Equipment choice will impact the level of skill and amount of time required for servicing.
Over time, as building structure and usage evolve, humidification strategies should be reviewed and realigned to meet new requirements. It is important to recognize that actual conditions in the building may differ from design specifications and to take into account how activities within the building are impacted by humidification.
Water hardness plays a critical part in an isothermal humidifier’s ability to maintain relative humidity setpoint. Minerals in untreated supply water cause scale buildup on humidifier heaters and heat exchangers. Scale acts as an insulator, reducing humidifier performance while increasing energy costs. The key is to remove minerals while they are still in solution and before they attach to humidifier components in the form of hard scale.
One way to mitigate the issues caused by hard water is to add water treatment in front of steam-generating systems. Using reverse-osmosis or deionized water will eliminate, or nearly eliminate, mineral accumulation. Integrated humidification systems, containing a steam humidifier and a reverse-osmosis system, are commercially available and finding great success in applications where space is limited and single-point water, electrical, and drain connections are desired for the water-treatment system and humidifier.
Understanding the application of humidification within your building will allow you to plan ahead to prevent operational issues or unscheduled system shutdowns. As building structure and uses change, adapt by selecting the proper humidification system for the application, especially considering water type and its effects on the system. Careful design, selection and maintenance will ensure a humidification system that provides years of trouble-free operation.