Corpus sync: neutrality remakes, note hygiene, datasheet relocation, transformer-split cross-refs
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title: Humidifiers
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# Scope {toc}
−## General {toc}
+## This standard governs the furnishing, performance, fabrication, and installation of factory-packaged humidifiers and their dispersion assemblies serving ducted air systems and conditioned spaces. {note}
−### This standard governs the furnishing, performance, fabrication, and installation of factory-packaged humidifiers and their dispersion assemblies serving ducted air systems and conditioned spaces. {note}
+## Humidifiers add water vapor to an airstream to maintain a minimum space relative humidity, protecting occupants, materials, processes, and the building envelope from the effects of excessively dry air. Dry winter air drives static discharge, respiratory discomfort, dimensional shrinkage of hygroscopic materials, and elevated airborne infection transmission; controlled humidification mitigates each of these. {note}
−### Humidifiers add water vapor to an airstream to maintain a minimum space relative humidity, protecting occupants, materials, processes, and the building envelope from the effects of excessively dry air. Dry winter air drives static discharge, respiratory discomfort, dimensional shrinkage of hygroscopic materials, and elevated airborne infection transmission; controlled humidification mitigates each of these. {note}
+## The work of this standard includes the humidifier, its dispersion assembly, integral and field controls, the high-limit safety, and coordination of water supply, drain, electrical service, and fuel or steam utilities. {note}
−### The work of this standard includes the humidifier, its dispersion assembly, integral and field controls, the high-limit safety, and coordination of water supply, drain, electrical service, and fuel or steam utilities. {note}
+## The humidifier shall be a factory-assembled, listed package selected from a manufacturer's standard production model line.
−### The humidifier shall be a factory-assembled, listed package selected from a manufacturer's standard production model line.
+## Custom-engineered humidifier assemblies shall not be substituted for a standard cataloged model without the Engineer's written approval.
−### Custom-engineered humidifier assemblies shall not be substituted for a standard cataloged model without the Engineer's written approval.
+## Selection of humidifier technology shall match the project's facility type, infection-control requirements, available utilities, and water quality.
−### Selection of humidifier technology shall match the project's facility type, infection-control requirements, available utilities, and water quality.
+## Coordination of the supply water source and treatment shall be governed by [[sync/hvac-water-treatment]] where treated water is required.
−### Coordination of the supply water source and treatment shall be governed by [[sync/hvac-water-treatment]] where treated water is required.
+## Dispersion-assembly thermal insulation, where the assembly is mounted in or adjacent to an air handler, shall conform to [[sync/mechanical-insulation]].
−### Dispersion-assembly thermal insulation, where the assembly is mounted in or adjacent to an air handler, shall conform to [[sync/mechanical-insulation]].
+## Control integration with the facility management system shall conform to [[sync/building-automation-system]].
−### Control integration with the facility management system shall conform to [[sync/building-automation-system]].
−
# Referenced Standards {toc}
## Referenced Standards List {toc}
−### The following standards are referenced in this document; the edition in force shall be that listed unless the Contract Documents require otherwise. {note}
+### The following standards are referenced in this document; the edition in force shall be that listed unless the Contract Documents require otherwise.
| Standard | Title |
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# Submittals {toc}
−## Submission Requirements {toc}
−
−### The Contractor shall submit the following action submittals for review before fabrication or ordering: {note}
−
## Action Submittals {toc}
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## Selection Criteria {toc}
−### The humidifier shall be selected for the air, water, and ambient conditions at its point of installation. {note}
+### The humidifier shall be selected for the air, water, and ambient conditions at its point of installation.
### Space humidity setpoints govern equipment sizing and control tolerance, and differ markedly by facility type. {note}
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## Sizing and Selection {toc}
−### The humidifier shall be selected from the manufacturer's standard model line at a rated capacity equal to or greater than the peak winter latent load. {note}
+### The humidifier shall be selected from the manufacturer's standard model line at a rated capacity equal to or greater than the peak winter latent load.
### Selecting from the standard model line avoids custom pricing and lead time and preserves spare-part availability. {note}
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## Supply Requirements {toc}
−### The supply-water source shall match the humidifier technology, since the wrong water type either disables the unit or contaminates the space. Mismatching water quality to technology is among the most common and most consequential humidifier specification errors. {note}
+### The supply-water source shall match the humidifier technology, since the wrong water type either disables the unit or contaminates the space. Mismatching water quality to technology is among the most common and most consequential humidifier specification errors.
### The supply-water source shall be confirmed against the manufacturer's water-quality specification before the unit is ordered.
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## Control and Safety Requirements {toc}
−### The humidifier shall be controlled to maintain the space humidity setpoint within the required tolerance while preventing duct wetting and condensation. {note}
+### The humidifier shall be controlled to maintain the space humidity setpoint within the required tolerance while preventing duct wetting and condensation.
### Modulating control gives the tightest humidity tolerance and is preferred for operating rooms, museums, data centers, and cleanrooms. Staged control is acceptable where a wider tolerance is permissible and lower cost is favored. {note}
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## Shipping and Storage {toc}
−### Humidifiers shall be delivered in the manufacturer's original packaging with cylinders, media, or nozzles protected. {note}
+### Humidifiers shall be delivered in the manufacturer's original packaging with cylinders, media, or nozzles protected.
### Equipment shall be stored indoors, protected from freezing, moisture, and construction dust until installation.
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## Warranty Terms {toc}
−### The manufacturer shall warrant the humidifier against defects in materials and workmanship for the period specified. {note}
+### The manufacturer shall warrant the humidifier against defects in materials and workmanship for the period specified.
### The warranty period shall begin at Substantial Completion or at documented startup, whichever the Contract Documents designate.
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## Parts and Replacement {toc}
−### Spare parts shall be furnished so that consumables can be replaced without unplanned downtime. {note}
+### Spare parts shall be furnished so that consumables can be replaced without unplanned downtime.
### Electrode cylinders have a finite service life, typically 1,500 to 4,000 operating hours depending on water quality, and must be replaced on schedule. {note}
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### The replacement-part service schedule shall state the expected service interval for each consumable based on the design water quality.