HUMIDIFIRST DT Series User manual

READ AND SAVE THESE INSTRUCTIONS
HUMIDIFIRST
ULTRASONIC HUMIDIFIERS
OWNER’S MANUAL
FOR
DT SERIES
(DUCT/AHU MOUNT)
ULTRASONIC HUMIDIFIERS
2-23-08

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HUMIDIFIRST
TABLE OF CONTENTS
Page
Introduction 4
Understanding humidification 4
Principles of ultrasonic humidification 5
Calculating humidification load 6
Humidifirst load calculation sheet 7
Water quality conversion chart 8
Physical dimensions of humidifier modules 9
Physical details of the humidifier module 10
Physical dimensions of the humidifier mounting shelf 11
Master panel sizes 12
Racking sizes for humidifier mounting 13
Specification for the humidifier module 14, 15
Field wiring schematic for HC-300 microprocessor 16
Field wiring sizing chart 17
Location of humidifier modules and Master Panel 18
Air flow safety switch physical data 19
Location of the humidity sensors 20
Design of ductwork or air handler applications 21

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HUMIDIFIRST
TABLE OF CONTENTS (continued)
Page
Positioning humidifier modules in Air Handlers (AHU) 22
Positioning humidifier modules in Ductwork 23
Installation Parameters & Guidelines
Mechanical 24
Water 25
Electrical 25
Start-up PRECAUTIONS 26
Humidifier start-up procedures 27 - 28
Trouble shooting during start-up
Field wiring 28
Humidity sensor 29
Proportional controller 29
Humidifier modules 30
Trouble shooting after the system has been started 31
DT - Series Explosion View 32
Maintenance
General maintenance 33
End of humidifying season shutdown 33
Transducers 33 - 34
Sensors 34
Warranty 34
Owner’s Manual disclaimer 34
DT Series Start-up Form 35 – 42

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HUMIDIFIRST
INTRODUCTION
Congratulations on your purchase of a HUMIDIFIRST duct mounted ultrasonic
humidifier – the highest quality and most “User Friendly” commercial/industrial
humidifier available today. Your selection of an ultrasonic humidifier provides you with
the benefits of this technology, including energy efficiency, minimal maintenance, and
healthy, uncontaminated moisture. And HUMIDIFIRST humidifiers are 100%
American made.
HUMIDIFIRST humidifiers are made of high-grade stainless steel. This ensures unit
longevity, minimal maintenance, and a clean, healthy humidifier.
UNDERSTANDING HUMIDIFICATION
Maintaining a specific relative humidity level in a building or a room is not an exact
science. Quality of construction, vapor barrier, air infiltration, and air exhaust all play a
role in the ability of a humidifier to maintain the relative humidity of a space. Also, some
older buildings may form ice in colder temperatures on the outside walls due to
humidified air seeping through cracks. Windows, too, may ice up when the outside
temperature drops. The type of window (e.g. single pane, double pane) can affect the
amount of window icing or sweating. The level of relative humidity in a space may also
affect the amount of window icing or sweating. For example, a building may have
moisture problems at 50% RH but not at 30% RH.
Also, relative humidity may fluctuate in a given space. If one were to walk around a large
room with a hand held relative humidity meter, variations in relative humidity would be
discovered. This is typically due to variations in space temperature. Relative humidity is
“relative” to temperature, and hence changes in space temperature will affect the relative
humidity of the air.

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HUMIDIFIRST
PRINCIPLES OF ULTRASONIC HUMIDIFIERS
Ultrasonic humidifiers vibrate a water mist into the air by using piezoelectric crystals
(transducers). The transducers are mounted in a basin of water approximately 1.5 inches
deep. Each transducer is approximately the size of a nickel and vibrates at approximately
1.6 megahertz, a speed so fast that the water above the crystal cannot follow the speed of
the transducer, causing the water to cavitate. This process creates a “finger” column of
water above each transducer, which emits very small water droplets into the air,
approximately one micron in diameter (similar in size to steam droplets). The water
droplets are so small that they evaporate almost immediately.
The water feeding an ultrasonic humidifier must be pure so that minerals and other
contaminants are not vibrated into the air. Such purity is achieved with de-ionized (DI)
water filters to remove all minerals and foreign matter from the water. DI water offers
additional benefits. It assures a pure, healthy mist for those breathing the air, and it
significantly reduces the amount of maintenance required for the humidifier, i.e. no
scaling or sludge to be removed from the humidifier pan.

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HUMIDIFIRST
HUMIDIFIRST humidifier sizing calculations
When calculating the humidification loads of a space we will generalize and assume that
the majority of the humidification load will come from two areas:
1. Ventilation, Exhaust, or Infiltration of air: most buildings have air exchanges with
the outside because of one or more of these three items.
A. Ventilation is a result of air conditioning systems bringing in outside air to
provide fresh air to the inhabitants.
B. Exhaust is the mechanical removal of air from a space when processes inside of
the building require the removal of dirty, hot or unwanted air.
C. Infiltration occurs when air comes into a space from outside. Air may come in
through small openings around doors, windows, ceilings, etc. Also, infiltration
often occurs from frequent opening of doors.
For each Cubic Foot per Minute (CFM) of outside air that is brought into the space,
moisture must be added to achieve relative humidity requirements.
2. Air conditioning: When an air conditioner runs, it removes moisture from the air.
This is known as Latent Cooling. If the air conditioner will be running during the
humidification season, then this dehumidification process must be taken into account.
The cooling ability of an air conditioner is normally rated by the manufacturer and is
stated in Sensible and Total cooling capacity in btu’s per hour. Subtract the Sensible
cooling capacity from the Total cooling capacity to get the Latent cooling capacity.
For every 1000 btu’s/hour of latent cooling capacity, a stable relative humidity level
requires that one pound of moisture be added to the air.
Please note that there are other factors that can affect humidification requirements, such
as moisture absorption of items in the space. These factors generally may be ignored
because most often they play only a minor part in the humidification requirements.
Contact Humidifirst for any unique applications.
See the next page for a simple chart that can be filled in and sent to Humidifirst. We are
happy to assist with the sizing of any humidification system.

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HUMIDIFIRST
HUMIDIFIRST can assist you with your humidifier sizing. Fax us (801-760-2777)
the following information:
Your name: _________________________________
Your Company: _________________________________
Phone number: _________________________________
Fax number: _________________________________
Project name: _________________________________________
Zone: _________________________________________
Indoor design conditions required: Temperature ________ ° F Relative humidity _______% RH
Outdoor (ambient) design condition: Temperature _______ ° F Relative humidity _______% RH
CFM of outdoor (ventilation) air: (see item 1 on previous page) _______________
BTU’s per hour of Latent cooling (see item 2 on previous page) _______________
Please do not hesitate to call us (561-752-1936) if you have any questions or if we can
help you with your calculations.

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HUMIDIFIRST
WATER QUALITY CONVERSION CHART
CONDUCTIVITY RESISTIVITY DISSOLVED SOLIDS GRAINS PER GALLON
(µS) (ohms) (parts per million , ppm) (GPG)
(also mg/liter)
0.125 8,000,000 0.0625 0.003655
0.167 6,000,000 0.08333 0.004873
0.2 5,000,000 0.1 0.005848
0.25 4,000,000 0.125 0.007310
0.5 2,000,000 0.25 0.014620
1.0 1,000,000 0.5 0.029240
2.0 500,000 1.0 0.058480
►5.0 200,000 2.5 0.146200 ◄
6.0 166,666 3.0 0.175439
8.0 125,000 4.0 0.233918
10 100,000 5.0 0.292398
12 83,333 6.0 0.350877
14 71,428 7.0 0.409357
16 62,500 8.0 0.467836
18 55,555 9.0 0.526316
►20 50,000 10 0.584795 ◄
22 45,454 11 0.643279
24 41,666 12 0.701754
26 38,461 13 0.760234
28 35,714 14 0.818713
30 33,333 15 0.877193
40 25,000 20 1.17
50 20,000 25 1.46
60 16,666 30 1.75
70 14,286 35 2.05
80 12,500 40 2.34
100 10,000 50 2.92
120 8,333 60 3.51
140 7,142 70 4.09
160 6,250 80 4.68
180 5,555 90 5.26
200 5,000 100 5.85
250 4,000 125 7.3
263 3,800 132 7.7
285 3,500 143 8.4
303 3,300 152 8.9

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HUMIDIFIRST
Humidifier module data
Humidifier Capacity Power Weight Dimensions Duct block No. of
Module (#/hr) (va) (lbs.) W x D x H (in.) (sq. ft.) Xcrs
DT-10 10.6 240 15 15.0 x 9.0 x 10 1.0 8
DT-20 21.1 495 20 23.0 x 9.0 x 10 1.6 16
DT-30 30.8 750 25 30.5 x 9.0 x 10 2.1 24
DT-40 39.6 960 30 39.9 x 9.0 x 10 2.5 30
DT-60 60.0 1410 46 42.1 x 15.5 x 10 2.7 47
DT-80 80.0 1860 56 53.8 x 15.5 x 10 3.4 62
W D
D
H
TOP VIEW SIDE VIEW
5”
H
FRONT/BACK VIEW

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HUMIDIFIRST
The Humidifirst DT series design gives you a choice of mounting the HUMIDIFIER
MODULE BASE with the electrical and water connections facing upstream or
downstream. This allows you to orientate the humidifier module base so that access to
the connection points is the most convenient for your application.
Please note that MIST DIFFUSER is reversible and must always be mounted so that
the AIR FLOW arrows are pointed downstream.
See page 32 for the explosion view of the DT-Series.
MIST DIFFUSER
ELECTRIC AND ¼” O.D. TUBE
WATER CONNECTIONS
DRAIN AND SAFETY OVERFLOW
CONNECTIONS ARE FROM BOTTOM
(3/8” MALE NPT CONNECTIONS)
HUMIDIFIER MODULE BASE

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HUMIDIFIRST
DT SERIES MOUNTING SHELF
Mount the humidifier module here
(four mounting holes) 1.5”
3”
Attach to ductwork/AHU here
10.5” (four mounting holes - field supplied screws)
15.1” (DT60, DT80)
DIRECTION OF AIR FLOW
W
.875” .875” 3” 4.5”
FRONT VI EW SIDE VIEW
MODEL W (inches) ▪When stacking shelves
vertically, use 1 ¼”
DT – 10 18.0 square tube
DT – 20 25.7 ▪Use ¼” X 1” bolts to
attach the humidifier to
DT – 30 33.2 the shelf. Use ¼” x 2 ¼”
bolts to attach corner
DT – 40 42.25 when stacking shelves
DT – 60 45.0
DT – 80 56.75
2-23-08 Drwg. no. DT – 005 Rev. F

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HUMIDIFIRST
The Master Panel
The Master Panel powers and controls the humidifier modules. It interfaces with sensors
located in the facility and will energize the humidifier module(s). All power for the
humidifier module(s) comes from the Master Panel. One (1) transformer, one (1) solid
state relay, and one (1) solenoid valve relay are provided for each humidifier module.
The ultrasonic transducers operate at 48 volts ac, the solenoid valve at 24 volts ac and the
controls operate at 24 volts AC or DC.
The physical size of the Master Panel will vary, depending on the number of humidifier
modules being powered and controlled, and the size of the transformer(s) required for the
various humidifier module sizes. For example, a Master Panel built for one DT-10
humidifier module will be 24” x 24” x 10”. A Master Panel built for eight (8) DT-80
humidifier modules will be 80” x 48” x 16”. The exact sizes of the Master Panel,
humidifier modules, and racks will be contained in the submittal information for a
particular project. Please feel free to contact the factory for this information in advance.
Please see page 16 for a general wiring schematic of the Master Panel.

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HUMIDIFIRST
Rack sizes for humidifier mounting
When installing multiple humidifier modules in the duct or air handler, they must be
mounted on rack(s) or shelving (see individual shelf on page 11). The structure should be
made of a polyester resin or of stainless steel. The installer may wish to provide the
racking, or it can be provided optionally by Humidifirst. The humidifiers should never be
placed one in front of the other. The racking system places one above the other. The
maximum number of modules per rack is five (5). For module requirements greater than
five, two or more racks may be used.
Humidifirst racks will be provided as follows:
1. Either polyester resin or stainless steel structure (choose one)
2. All humidifier modules to be mounted on the shelves.
Number of humidifier Minimum Height
Modules (in.)
2 30
3 42
4 54
5 66

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HUMIDIFIER MODULE SPECIFICATIONS
The ultrasonic humidification system shall include packaged, self-contained ultrasonic
humidifier module(s) using the principle of ultrasonic nebulization. Each transducer
circuit shall use the “thickness vibration method” of humidification via a piezoelectric
converter. The ultrasonic transducers shall convert the electric energy into mechanical
energy, causing the water to cavitate, resulting in the production on one micron sized
water particles. The design of the humidifier housing shall prevent larger droplets from
leaving the humidifier assembly.
Each humidifier module shall use a multiple of ultrasonic transducers that vibrate at
approximately 1.6 megahertz, producing a droplet size of approximately 1 micron (.52
cubic micron droplet volume).
The humidifier shall consume no more than 30 watts per pound of humidification
generated.
The ultrasonic humidifier shall not produce any unacceptable noise.
The humidifier module(s) shall contain no fans and shall be designed to be located inside
of ductwork or air handlers and to receive air at velocities of 300 feet to 1500 feet per
minute.
The ultrasonic humidifier shall not require a flush cycle and shall have instant on and off
operation in order to maintain precise room relative humidity.
The humidifier housing and discharge nozzles shall be made of stainless steel; plastic is
not acceptable.

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HUMIDIFIER MODULE - continued
Each humidifier shall have the following components:
A. Solenoid valve to control water flow into the humidifier
B. Float switch to control water level.
C. Float switch to provide for low water shutdown
D. Piezoelectric crystals (transducers)
Mist discharge diffuser
The mist discharge diffuser shall be adjustable so that when field conditions dictate
higher velocities, air can be restricted and small droplet size can be maintained.
Solenoid valve and low water safety control
No circuit boards for control of the solenoid valve or low water safety shall be permitted
in the humidifier module. Damp conditions can deteriorate the circuit boards and result
in high maintenance costs. All such controls shall be located inside of the central Master
Power and Control Panel. Indicator lights in the Master panel shall be energized when
the solenoid valve is energized and when the low water safety/high temperature safety
cut-out is in effect.
Solenoid valve
Stainless steel solenoid valves shall be provided when de-ionized or reverse osmosis
water is being used.
Hermetically seal solenoid valve coils shall be used.
Water connection kit
A water line connection kit to each humidifier module shall be provided and include a set
of quick disconnect service valves (checked) to easily isolate the humidifier when
servicing.

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HUMIDIFIRST
Field Wiring Schematic for HC-300 Controller
Field wiring to Master Panel
MASTER PANEL ◄Common alarm
(2 wire dry contact signal)
HUMIDIFIRST
◄Air proving circuit
1. Microprocessor (2 wire- 24 Vdc)
2. Solid state relays ◄Remote shut down
(2 wire- 24Vdc)
3. Power transformation
◄Analog signals:
4. Controls - Humidity sensor
- Humidity high limit sensor (optional)
- Water quality sensor (optional)
- Air speed sensor (optional)
(2 wire shielded cable, with
drain, 4-20 ma)
◄Options: - Air temp too low
- Air temp too high
- Ambient Temp setback
- Water leak detected
(2 wires, 24 Vdc)
◄Drain valve(s) (optional)
Humidifier Module 1 One valve per humidifier module.
The valves can be wired together in
parallel, and then one set of wires
can be run to the Master panel.
(2 wires)
Humidifier Module 2 ◄Power supply to Master panel
As specified
◄Power/control wires to EACH
humidifier module
10 wires, includes grnd, DT10, 20, 30, & 40
Humidifier Module “n” 12 wires, includes grnd, DT60 & 80

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HUMIDIFIRST
Transducer power wire sizing from the Master Panel to the humidifier module(s)
1. Field wiring for transducer power (hot and common) typically has a
voltage range of 42 to 50 volts.
2. Check the wiring diagram for number of transducer rows, depending on
the model they will vary from 1 to 3 rows.
Model Transducer Current Minimum Wire size
rows (amps per row) (AWG)
0-25 ft. 50 ft 75 ft 100 ft
DT-10 2 3 16 16 14 12
DT-20 2 6 16 14 12 10
DT-30 2 9 16 14 12 10
DT-40 2 11 16 14 12 10
DT-60 3 12 16 14 12 10
DT-80 3 15 14 12 10 10
IMPORTANT: Use the above as a guideline only. Refer to the National Electric Code
when sizing wire for your specific application. Type of wire, number of wires in the
conduit, ambient temperature, etc., all impact the wire sizing.
The wire gauge of the 10-foot harness that is shipped with the humidifier may be less
than the gauge listed above but is generally adequate for most applications that are less
than 10-foot in length.

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HUMIDIFIRST
Layout of your Humidifirst Ultrasonic humidification system
Locating the humidifier module(s)
Properly locating the humidifier module(s) is very important and by doing so will
eliminate many potential problems. Adequate air velocity (speed and direction),
temperature, turbulence and return air relative humidity all play a role in the distance
required for full evaporation. More than one module may be (and often is) used to
achieve the desired design capacity. When using multiple humidifier modules, never
locate one module directly in front of the other. The modules can be located one above
the other or can be mounted in a stepped configuration with the highest humidifier being
the first one in the air stream. The optimal air velocity above the humidifier module is
between 800 to 1000 feet per minute (fpm). If the air speed is slower than 300 fpm, the
transducers may overheat. If air speed is slower than 800 fpm, output capacity may be
reduced. If the air speed is faster than 1000 fpm, larger water droplets may be drawn out
of the humidifier module and cause wetting in the ductwork. Remember to subtract the
area of the humidifier module(s) from the cross-sectional area of the ductwork to
determine the actual air speed at the humidifier module (the smaller the free area the
faster the air speed).
See the typical duct/AHU installation sketch on the following pages.
See the “Installation Parameters & Guidelines” on the following pages.
Locating the Master Panel
The Master Panel, depending on its size, can be mounted on the side of the air handler, on
an adjacent wall or, for larger cabinets, be floor mounted. See the previous charts for
correct wire sizing and Master Panel sizes.

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AIR PRESSURE SWITCH
6.25"
2.81"
3.75" 3.79"
.187"DIA.
MOUNTING HOLE
SENSITIVITY
ADJUSTMENT
SCREW
WIRE PUNCH OUT
FIELD WIRING
TERMINALS
1/4" OD TUBE
CONNECTION
POINT
LOWPRESSURE HIGH PRESSURE
1. The air pressure switch must be mounted to a vertival surface, as this device
is gravity sensitive.
2. The adjutable range of the switch is from 0.05"WC to 2.0"WC with an accuracy
of +/- 0.02" WC
3. Adjusting the screw in a clockwise directionincreases the air presure required
to actuate the switch
4. The maximumsustained rating of the switch is 0.5 PSI.
5. The switches ambient air temperature range is -40Fto 180F
TERMINAL & SENSITIVITY
SCREWCOVER

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HUMIDIFIRST
Locating the humidity sensors
Two styles of humidity sensors are available for sensing the relative humidity – wall
mount or duct mount. Each offers unique features and benefits. Please consult the
factory to determine the best sensor(s) for your application.
A. Locating wall mounted sensors
Install the sensor where the relative humidity and the temperature will be most
representative of the environment that is to be maintained. Consider the following when
locating the sensor:
1. Do not locate it near cooling or heating coils, or air diffusers
2. Do not locate it where it will have direct sunlight exposure
3. Do not install it on an outside wall
4. Nothing should restrict vertical (upward) airflow through the sensor
B. Locating duct mounted sensors
Duct mounted sensors can be used for two purposes:
1. Measuring the relative humidity in the return air ductwork, upstream (before) of
the humidifier. Locate the sensor where the relative humidity will be most
representative of the environment that is to be maintained.
2. Using the sensor for “high limit” sensing so that the humidity level in the
ductwork does not exceed the saturation point. The sensor for this application is
mounted downstream (after) of the humidifier. It must be located far enough
downstream of the humidifier so that un-evaporated mist does not collect on the
sensor. This distance is normally at least 20 feet downstream of the humidifier.
Consider the following when locating the duct-mounted sensor:
1. Do not locate near heating or cooling coils
2. Do not locate in turbulent airflow (near elbows, fans, etc.)
3. Install where the air velocity is at least 200 feet per minute (1 meter per second)