Nortec AIRFOG User Manual
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1502247-E | 18 JUL 2011
AIRFOG
Series
Installation and
Operation Manual
Includes installation, operation
maintenance and troubleshooting
information for your AirFog Series
Atomizing humidifier
Thank you for choosing NORTEC.
INSTALLATION DATE (MM/DD/YYYY)
MODEL #
SERIAL #
Proprietary Notice
This document and the information disclosed herein are proprietary data of WALTER MEIER LTD. Neither this
document nor the information contained herein shall be reproduced used, or disclosed to others without the
written authorization of WALTER MEIER LTD., except to the extent required for installation or maintenance of
recipient’s equipment. All references to the NORTEC name should be taken as referring to WALTER MEIER LTD.
Liability Notice
NORTEC does not accept any liability for installations of humidity equipment installed by unqualified personnel
or the use of parts/components/equipment that are not authorized or approved by NORTEC.
Copyright Notice
Copyright 2011, WALTER MEIER LTD. All rights reserved.
Contents
1 Introduction
1 AirFog Humidifiers
1 AirFog Family of Products
1 AFE Principle of Operation
2 General AirFog Technical
Considerations
5 Installation
5 Nozzle System Layout
7 Zones
7 Introduction
7 Supply Feed Lines
7 Cleaning
7 Mounting of Nozzles
9 Connecting Nozzles
9 Saddle Clamp Installation
11 Vacuum Valve
11 Pilot Operated Air Regualtor
15 Primary Air Pressure Control
15 Primary Water Pressure Control
15 Control Panel
15 Electrical Wiring
18 Pilot Lines
19 AFE Self Contained AirFog
Systems
19 AFE Mini Systems
21 AFE Octo Systems
26 AFE, Mini, and Octo Start-
up Procedures
26 Introduction
26 Compressed Air Supply
26 Water Supply
27 Self Cleaning Cycle Adjustment
28 Setting the System for Normal
Operation
30 AFE, Mini, Octo Shut Down
Procedures
31 Maintenance
31 Seasonal Maintenance
31 Seasonal Startup
32 Unscheduled Maintenance
32 Vacuum Valve Testing
32 Checking For Vacuum
Leaks
34 Troubleshooting
35 Replacement Parts
35 Repair Kits
36 Spare Parts / Exploded
Views
21 Installation Procedure
Introduction
Note: Prior to installing any AirFog product carefully READ through this entire guide, it
contains valuable information, which will assist in all aspects of the installation.
Applicability
This document is applicable to all Nortec AirFog system components purchased after February
2004. If the designer has existing system components purchased prior to February 2004, the
Nortec Technical Service Department should be consulted to determine compatibility with the
newer equipment, parts and external interfaces.
AirFog Humidifiers
Nortec AirFog systems use the nozzle humidification technology of injecting droplets of cold
water directly into the air. This method of humidification has the following advantages over
steam humidification:
Lower frequency of maintenance.
Systems are mainly mechanical (water pipes and air pressure) with only a 24 VAV power
requirement in the control panel.
A “no cost” air cooling benefit due to latent heat of vaporization extracting heat from the air.
Maintenance is primarily focused on keeping the air compressor operational.
Change of components is fast and requires minimal system disassembly.
AirFog Family of Products
The AirFog family is Nortec most advanced adiabatic humidifiers. There are groups of products
that fall in this family: applied products and packaged products.
The applied products group describes systems that are tailored specifically for each application:
AFE Nozzle systems use compressed subsonic air flows and water to create a fine mist that
is sprayed directly into a space.
The packaged products group describes systems that are ready to operate out of the box, and
need only be connected to power, air, and water. These products include:
AFE Mini: Systems are wall mounted and have 1 or 2 AFE nozzles.
AFE Octo: Systems are ceiling mounted and available in many configurations including
modulating versions, and have between 3 and 8 AFE nozzles.
This manual describes the installation, operation, and maintenance of all AFE, Mini and Octo
systems.
AFE Principle of Operation
The AFE nozzle uses air flow and the Bernoulli principle to siphon water out of zero psig
AirFog Installation Manual | 1
water distribution pipes. Increases in air velocity (by increasing air pressure) will increase the
vacuum pressure and increase the rate that water is siphoned into the nozzle. As the water
exits the nozzle it is broken down into a fine mist by a shearing action created by the
compressed air. Increases in air supply pressure also means that the exiting mixed flow is at
a higher velocity.
Since AFE nozzle systems use a zero psig water pressure feed network, the water feed
system and nozzles at the same height as the water pressure reduction regulator (vacuum
valve). Valleys or peaks in altitude will adversely affect performance and in some cases will
prevent the nozzles from producing any output. If obstructions prevent straight level piping,
the water and air network delivery pipes must be routed under the obstruction. It is vital that
the water pipes, downstream of the vacuum valve, never be elevated higher than the
nozzles.
General AirFog Technical Considerations
Adiabatic Cooling Phenomena
There are no heating elements in any of Nortec’s AirFog humidifiers. Water is injected directly
into the air at the temperature it is supplied. As the droplets evaporate they extract sensible
from the surrounding air at a rate of approximately 1,000 BTU per pound of water evaporated.
This causes the temperature of the air to decrease, meaning that both humidity and cooling are
provided simultaneously. This could be a significant energy saving technique if mechanical
cooling is required. Since humidification is most often required when the exterior atmospheric
temperature is below room temperature, there is a necessity to warm the air either prior to
addition of the water droplets or after absorption of the droplets into the air. It is recommended
to add the moisture after the air is heated as this dramatically reduces the time and distance
taken for the water droplets to evaporate.
Humidification Zones (In Space Applications)
The movement of humidity through a space is very rapid. In applications where accurate
humidity control is essential, it is important that the structure be reasonably air-tight, well
insulated, and have good vapor barriers, to prevent humidity from escaping to the outside. If a
large amount of infiltration or exfiltration is encountered it may be necessary to oversize the
system to compensate for this.
AFE systems are frequently used in large factory applications for dust and static suppression.
Often these structures have large doors open for loading and unloading of goods. Keeping
doors closed, except when needed for movement of goods, can improve the performance of the
humidification system by containing humidity levels within the space.
Absorption Distance
Water mist sprayed by the AFE nozzle requires a certain distance to be absorbed by the air.
Absorption distance is affected by many factors including temperature, existing humidity levels
and air pressure. However, in general increasing the air pressure (and hence the water flow) to
the nozzle will increase the absorption distance since more water is being sprayed. It is
important to follow the clearances in this guide to prevent the accidental wetting of structures
or machinery.
2 | AirFog Installation Manual
Compressed Air
Nortec AirFog systems use compressed air as the control fluid. Compressed air is provided by a
compressor (supplied by others) or series of compressors. The modular approach to the Nortec
AirFog systems permits the designer to consider the cost implications of using multiple smaller
horsepower compressors rather than one very large compressor. By using a multiple
compressor design solution, system reliability is increased, maintenance is possible without
shutting down all zones, and capital cost is often reduced.
It is recommended that air free of oil and moisture (control quality air) be used with AirFog
systems. All air compressors will produce moisture, which must be removed using a
refrigerated air dryer. Excessive amounts of water in the air lines will reduce nozzle
performance, and in extreme cases will prevent the nozzle from producing any mist. Oil must
also be removed from the compressed air through the use of oil removal filters.
Air pressure loss can be managed by reduction in the air pipe length, elimination of
unnecessary elbows, valves and flow restrictions, increasing the diameter of the primary
delivery pipe to the zones and elimination of leaks.
Water Quality
AirFog AFE nozzles are controlled from 316 stainless steel and can be used with potable,
reverse osmosis, and deionized water types. Potable water contains dissolved minerals that will
precipitate out of the water in the form of dust as the water evaporates. These minerals are
usually not harmful to the occupants of a space or to presses such as woodworking , printing,
paper, storage facilities, etc., however, clean area applications such as computer rooms,
electronics manufacturing, laboratories, paint, or fired finish areas may be adversely affected
by mineral dusting. In these cases Nortec recommends the use of reverse osmosis or
deionization systems to reduce the mineral content of the water before it enters the humidifier.
If you have questions regarding the suitability of the water for your application, please contact
the design engineer or your local Nortec representative.
Installation Tools and Equipment
The designer should have already provided drawings of the proposed AirFog humidification
system physical layout. These drawings and parts list should clearly identify the system
components by name and part number, physical spacing, zone identification and comments on
nozzle location and pointing directions.
During installation there will be a requirement to:
Attach mounting brackets to walls, ceilings or other structures, which may be higher than six
feet off the floor.
Cut and join copper, stainless steel or plastic pipe using standard plumbing joining
techniques.
Connect low voltage wiring to the control panel.
Connect plastic tubing.
The installer should have all the tools and be certified to perform these plumbing, mounting
and electrical tasks.
AirFog Installation Manual | 3
Parts
A parts list should be included with the drawings developed by the designer. Not all the
necessary parts are provided by Nortec. The following parts are supplied by others:
Pipe, elbows, pipe hanger and mounting hardware for inside HVAC units, T-joints, pipe size
adapters, Teflon sealing tape and other plumbing supplies from a local plumbing supplier.
Pipe material is either copper, stainless steel or plastic and should be specified on the
designer produced drawings.
Wire for the electrical connections is 18 gauge standard insulation, which can carry 24 Volts
AC at 1 amp. This wire can be purchased from most electrical suppliers.
Nails, screws, bolts, threaded rods, anchors, rivets etc. to attach mounting brackets to the
structure. The fasteners used will depend on the material used in the mounting surface.
Insulation for the cold water pipe feeding the system is required to prevent water vapor from
condensing and dripping on other structures, machines, personnel or materials.
The Nortec supplied parts should be checked against the designer’s drawings and parts list
to ensure the correct quantity of the correct part numbers are available.
4 | AirFog Installation Manual
Installation
Nozzle System Layout
If a drawing for the proposed system was not supplied, then it is recommended that one be
created prior to installing the system. With reference to the AirFog Engineering Manual, review
the site where the nozzle system is to be installed. The location of equipment, lights, pillars and
other structures should be drawn on the floor plans. The proper selection and location of the
nozzles is very dependent upon these obstructions. Figure 1: Typical Nozzle Layout, can be
used as a guide for identifying the various components used with a system.
The supply and feed lines for the system should be kept in straight unobstructed lines where
possible. Air and water distribution network pipes are to be installed level along walls, pillars or
hung from the ceiling. Avoid placing the lines over top of equipment and other areas, which will
make it difficult to gain access at a later date. If the lines have to be routed around an obstacle
such as a beam, always go under the obstacle, never over it.
Figure 1: Typical Nozzle Layout for Wall Mounted System
AirFog Installation Manual | 5
Install as close to control
panel as possible.
Figure 2: Multi Zone Layout
6 | AirFog Installation Manual
Zones
Introduction
It may be necessary to break down the space to be humidified into zones. Limitation of the
control devices and maximum run of feed piping may indicate the need for multiple zones.
Refer to the Engineering manual for detailed limitation of components. Up to four zones can be
controlled from one control panel, additional zones can be added with the use of a pilot air
regulator acting as a volume booster for the pilot signal. See Figure 2: Multiple Zone Layout.
Supply Feed Lines
Main supply lines connecting to the system must be sized to handle system flow volumes and
pressures. Connections to each zone should have an isolation valve installed by using a
NORTEC supplied primary pressure control section as illustrated in Figure 3: Water and Air Line
Pressure Control. Primary air pressure feed to each zone should not exceed 90 psig. Water
feed pressure is not to exceed 25 psig for AFE, Mini and Octo hardware. Supply water pressure
is not to exceed 65 psig for AFD systems.
Both water and air lines must be installed as per the mechanical drawings using standard
plumbing joining techniques. The spans must not be greater than 5 feet without a supporting
bracket. For long runs of piping, expansion joints may be needed and these joints must meet
local building codes. When using Nortec supplied saddle clamps, the maximum line size for
supplying to nozzles is 11/16” O.D. If saddle clamps by others are used, please size fittings to
match the pipe.
Cleaning
Manual valves must be installed at the ends of all lines to facilitate cleaning and drainage of
lines. Cleaning is done by temporarily connecting the pipes to a compressed air source at one
end of the pipe. The other end of the pipe must not be connected to any equipment but be free
to allow the egress of foreign matter. Care must be taken to protect personnel, animals,
machines or other sensitive material from the potentially hazardous and contaminating matter,
which will exit at high speed from the opening.
Note: Cleaning of the lines of all foreign material prior to connecting any system component
is critical, failure to maintain clean lines may void the warranty.
A.
Mounting of Nozzles
Each supplied Nortec nozzle has a 3/8” NC 16 threaded port on the under side of the nozzle
which is used to fasten the nozzle to a mounting bracket, as illustrated in Figure 4: Nozzle To
Bracket Interface or Figure 5: AFE Nozzle Ceiling Mounting. If other than NORTEC supplied
mounting hardware is to be used, ensure correct bolt and thread size is used. Nozzles can be
mounted in any elevation angle as water throughput capacity is not affected by this orientation.
However, AFE nozzle capacity is sensitive to vertical height differences to the vacuum valve.
The maximum nozzle installation height allowable above the water supply line is 12” (30 cm).
AirFog Installation Manual | 7
A
Primary Air Pressure Control Section
Primary Water Pressure Control Section
Figure 3: Water and Air Line Pressure Control
Lag Bolts
Mounting Holes
For 1/4" Lag Bolts
Saddle
Clamp
Polytube
(Supplied By Others)
Saddle Clamp
Polytube
FE Nozzle
Wall Support Bracket
Figure 4: Nozzle to Bracket Interface
8 | AirFog Installation Manual
t
Threaded Rod
(Supplie d B y O th er s)
Nozzle Support
Bracket
Water Line
Air Line
Installation Hardware Package
(Includes Saddle Clamps,
Adapters And Tubing.)
AFE Nozzle
Supply Lines
To Nozzles
(By Others)
Pipe Hanger
(By Others)
Figure 5: AFE Nozzle Ceiling Mounting
Connecting Nozzles
All the supplied nozzles have two inlet ports with push in, quick release style fittings as shown in
Figure 6: Quick Release Fittings. These fittings are only designed for use with 1/4” O.D. plastic
tubing. If other than Nortec supplied tubing is to be used, it must be a high grade uniform
tubing from a reputable supplier.
The Nortec supplied fitting uses an o-ring to seal the O.D. of the tubing and finger clamps to
hold it in place. Failure to use proper size tubing may result in poor sealing and cause system
failure. The tubing MUST be cut square using a knife or plastic tube cutter rather than pliers.
To connect the tube to the nozzle simply push the tubing into the nozzle fitting until it reaches
the bottom. Gentle pulling of the tube without movement is a good indication that a proper seal
has been made.
Allow enough free tubing to permit the nozzle to swivel horizontally or vertically for future
pointing alignment.
Saddle Clamp Installation
The type of clamp used by Nortec, as shown in Figure 7: Saddle Clamp, requires that the pipe
be drilled first. Drill a 1/4” hole squarely into the air and water pipes close to each nozzle
within 24” (60 cm). Place the sealing gasket on the male part of clamp, insert it into the drilled
hole, then clamp it into place using the provided screws. The saddle clamp has a 1/8” FNPT
port; install either the supplied compression fitting or another style fitting suitable for plastic
ubing. Two saddle clamps, one for air and one for water, are required for each nozzle.
Note: Not to be used with DI water. For DI water use stainless steel tee.
AirFog Installation Manual | 9
Cut-away View of Quick
Disconnect Fitting
Seal
O-Ring Seal
NPT Threads
1/4" Tubing
Tubing MUST be cut
to ensure proper seal. Use sharp knife,
not w ire cu tt e r s or p lie r s.
Locking Ring
1/4" Tubing
Locking Fingers
PERPENDICULAR
Figure 6: Quick Release Fitting
Fitting
Top
Clamp
Screw
Gasket
Bottom
Clamp
10 | AirFog Installation Manual
Figure 7: Saddle Clamp
Vacuum Valve
The vacuum valve must be centrally located so there are approximately an equal number of
nozzles being fed from each of its two output ports (one on the left side and the other on the
right side). There is a mounting bracket supplied with each vacuum valve. Figure 9: Vacuum
Valve Interfaces illustrates the plumbing interface details. Elevation of the valve is very critical,
as is the positioning of the nozzles. The maximum height above the nozzle supply line the valve
should be installed is 12” (30 cm). Never install the vacuum valve lower than the nozzle water
feed lines.
The water flow rate through this valve is limited to 24 GPH, which limits the number of AFE
nozzles it can supply to 16. If more than 16 nozzles are to be installed, then the system must
be broken into zones using multiples of 16 (or less) nozzles with each zone controlled by its own
vacuum valve. One control panel can control multiple zones by “T” ing off the single control
panel air pilot output.
Air pressure from the control panel is used to open the water safety valve permitting water to
enter the vacuum valve, which controls the water feed to the nozzles. Figure 8: Vacuum Valve
Operation explains the operation of this water regulator. The vacuum valve assembly has three
sub-components. As illustrated in Figure 9: Vacuum Valve Interfaces. First, the safety valve
interfaces directly with the primary water supply to open or close on command from the control
panel. Loss of pilot air pressure (below 10 psig) will automatically close this valve to prevent
water proceeding beyond this point. In series with, and downstream of the safety valve, is the
water regulator. The water regulator is used as the first stage of water pressure reduction. The
water regulator reduces the supply water pressure to a range between 5 and 10 psig. This is
set manually at time of installation. Please note that system performance is not sensitive to the
exact setting as long as the pressure is within this range.
The second stage of water pressure reduction is the vacuum diaphragm, which drops the
pressure to ambient (0 psig). Output is through two exit ports on the underside of the vacuum
valve. This permits the nozzle to draw water from the supply as required rather than having
pressure force it into the nozzle. The siphoning action of the nozzle is controlled by the pilot
operated air regulator.
On top of the vacuum valve is a thumb wheel adjustment for adjustment of the AirFog droplet
size. The adjustment changes the volume of water to the nozzles. A reduction in available
water for a constant air flow results in smaller droplets and a finer spray. This adjustment can
be used to reduce the water throughput if there is a problem with water droplets reaching the
floor.
Pilot Operated Air Regulator
The pilot operated air regulator controls the air supply to the nozzles and is illustrated in Figure
10: Pilot Air Regulator. The pilot regulator is modulating flow controller rather than a simple
On/Off valve. The greater the pilot air pressure, the greater the air pressure fed to the nozzle
supply network. This means that the Control Panel is able to request a proportional opening of
the Air Regulator simply by varying the pilot pressure. There is a linear 1:1 relationship between
the pilot pressure and the output pressure drop. A pilot air pressure of 25 psig (172.5 kPa) will
drive the air regulator to have an output of 25 psig (172.5 kPa). A pilot pressure of 50 psig will
drive the air regulator to have an output of 50 psig. The pilot air pressure range is from 0 to 70
psig.
AirFog Installation Manual | 11
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