Modulating humidistat
Humidistat that produces a modulating control signal
Mole
Term similar to a dozen except that the number of things in a dozen is 12, and the number of things in a mole is 6.023 x 1023. Avagadro figured out that this is the number of atoms (or molecules) in the atomic (molecular) weight of that substance expressed in grams. For example, the molecular weight of water is 18 so, a mole of water molecules has a weight of 18 grams (18 g/mole).
Molecule
At least two atoms held together by covalent bonds. Molecules are neutral
because they do not have a net charge like ions. Water (H2O) is a molecule.
Molecular weight
Molecular weight is determined by adding the atomic weights of each element in a molecule. The atomic weight for hydrogen is 1 (its nucleus contains only 1 proton), and oxygen’s atomic weight is 16 (its nucleus contains 8 protons and 8 neutrons for a total of 16). So, H2O has a molecular weight of 18. PH pH is a measure of the acid or base levels of the water. H+ is acidic and OH- is basic. The pH range is 0 to 14. The number is technically the negative log10 of the H+ ion concentration. 7 is neutral (hydrogen ions and hydroxyl ions are equal). > 7 is basic (hydroxyl ions are greater than hydrogen ions). < 7 is acidic (hydrogen ions are greater than the hydroxyl ions).
Multiple-tank control
Single-point control of multiple humidifiers
Natural ventilation system
Ventilation system without the use of a mechanical device
NEMA-1 safety switch
External disconnect for electric humidifier
NEMA-12 cabinet
Control cabinet with dust proof rating
NEMA-4 cabinet
Control cabinet with dust and drip proof rating
Nonpressurized steam dispersion
Dispersion systems designed to accept steam from DriSteem steam generators
NPT
National pipe thread
Open space
Area with no ductwork
Outside air intake rate
Rate at which outside air enters a ventilation system
Outside air volume
Air volume entering a ventilation system from outside
Outside conditions
The outside dry bulb temperature and relative humidity
Pilot positioner
Positioning a valve using a pilot air control signal
Polyvalent ion
An ion that has a charge greater than one.
Potable water
Tap (or drinking) water
Pressurized steam dispersion
Direct or live steam dispersion product
Project, DriCalc
Job name or reference number
Redundant tank
Backup system or tank
Relative humidity (RH)
The wetness or dryness of air at a given temperature and pressure
Remote temperature sensor
Prevents condensation on structural members
Rise
The minimum nonwetting height above the steam outlet
RO/DI water
Reverse-Osmosis filtered, or DeIonized water
Same-side piping
Steam supply and condensate connection are on same side of the steam dispersion assembly
Sealed combustion
Air for combustion is ducted directly to a humidifier
Seismic certified
Humidification equipment that has gone through third party shake testing to validate operation after a seismic event. May have additional or different support methods or structural enhancements
Separator
Steam and condensate separating device
Separator orientation
Separator may be in the upright or horizontal position
SI units
System International metric unit system
Softened water
Water where calcium and magnesium ions have been replaced with sodium ions
Solenoid valve
Electromagnetic valve
Spread
The minimum nonwetting width from the steam outlet
SSR sequencing modulation
One heater stage is controlled by a Solid-State Relay while others are controlled contactors
SSR, 100%, modulation
All heater stages are controlled by a Solid-State Relay
Steam dispersion enclosure
Box that contains the header
Steam dispersion panel
Dispersion system with a frame or case
Steam hose
Hose that connects a steam generator to a dispersion assembly and designed to withstand high temperatures
Steam trap
Device that prevents steam flow but allows condensate to flow through
Steam valve Cv/Kv
Flow coefficient of a valve
Steam valve size
Inlet and outlet size of the steam valve body
Steam-to-steam
Generating nonpressurized steam via direct steam and a heat exchanger
Strainer
Steam filter upstream of the steam valve to remove debris
System (DriCalc)
Humidification system for a space
Tag name
Individual humidifier identification
Temperature switch
Temperature activated switch prevents the operation of a control valve
Throw
The minimum nonwetting horizontal distance from the steam outlet
Total air volume
Total volume of air in a ventilation system
Total dissolved solids (TDS)
All substances that are dissolved in the water. Principal TDS contributors: calcium and magnesium carbonates and bicarbonates (principal scale forming substances) among others.
TP modulation
Time-proportioned modulation
Trapeze
Hanging support system for a humidifier
Tube spacing on-center
Spacing between dispersion tubes, measured from the tube center line
Tubing
Thin walled pipe designed to withstand high temperatures
Tubing, insulated
Thin walled pipe with insulating cover
Vac
Volts alternating current
Valve control, electric
Electric control signal for steam valve(s)
Valve control, pneumatic
Pneumatic control signal for steam valve(s)
Venting, horizontal
Side wall venting
Weather cover
Enclosure that prevents rain from wetting humidifier components
Wet bulb temperature
An expression of the temperature of the air when a wick or sock, wetted with water, encases the sensing element of a dry bulb thermometer and air is passed over it at a velocity of 700 feet per minute or more
Y connector kit
Includes a Y connector, three hose cuffs, and six hose clamps