
• Energy
Efficient
• Easy to
Install
• Extended
Service Life
• Energy ecient compact blower coils
• Ideal for educational, hospitality, multi-family, or other commercial environments
• Designed for ducted applications
• Nominal CFM range of 600 to 3,000 CFM
Modular Hi-Rise Series Fan Coils
INSTALLATION, OPERATION, & MAINTENANCE MANUAL
Modular Hi-Rise Models:
MPY, MXY, MAY/MBY Ditto,
MMY/MSY, MUY, and MGY

Modular Hi-Rise Series Fan Coils
INSTALLATION, OPERATION, & MAINTENANCE MANUAL
International Environmental Corporation (IEC) works continually
to improve its products. As a result, the design and specifications
of each product may be changed without notice and may not be
as described herein. Please contact IEC for information regarding
current design and product specifications. Statements and
other information contained herein are not express warranties
and do not form the basis of any bargain between the parties
but are merely IEC’s opinion or commendation of its products.
Manufacturer’s standard limited warranty applies.

Modular Hi-Rise Series Fan Coils
INSTALLATION, OPERATION, & MAINTENANCE MANUAL
SECTION I – Receipt and Initial Installation
4 Receipt
4 Unpacking and Inspection
5 Handling and Installation
SECTION II – Product Line Specific Installation
5 Part 1 – Universal Hi-Rise Units (MUY)
6 Potential Unit Configurations
6 Unit Knockout Locations (Typical)
7 Supply, Return, and Drain Riser Installation
8 Riser to Unit Installation
8 Riser to Drain Installation
10 Supply Air Installation
10 Part 2 – Ditto and Siamese Ditto ( MAY/MBY)
12 Part 3 – High Rise, Ditto, and Siamese Ditto (MPY, MAY/
MBY, MMY/MSY)
12 Supply, Return, and Drain Risers
13 Part 4 – Mega Mod Units (MGY)
14 Supply, Return, and Drain Risers
14 Riser to Unit Installation
15 Riser to Drain Installation
16 Unit Knockout Locations (Typical)
16 Supply Air Installation
17 Demolition
18 Installation
SECTION III – Finishing Installation (All Models)
18 Grille/Ductwork Installation
18 Outside Air Installation (if required)
18 Electrical Connections
19 Exposed Unit Touch-up and Repainting
19 Concealed Unit Enclosure
SECTION IV – Start-up (All Models)
20 Operating Conditions
20 Cooling/Heating System
20 Air System Balancing
21 Control Board Adjustment
22 Water Treatment
22 Water System Balancing
23 Controls Operation
SECTION V – Routine Maintenance (All Models)
23 Motor/Blower Assembly
23 Coil
24 Electric Resistance Heater Assembly
24 Electrical Wiring and Controls
24 Valves and Piping
24 Filters, Throwaway
25 Filters, Permanent
25 Drain
25 Replacement Parts
SECTION VI – Checklists
25 Receiving and Inspection
25 Handling and Installation
25 Cooling/Heating Connections
25 Ductwork Connections
25 Electrical Connections
26 Unit Start-up
26 Terms and Conditions

SECTION I – Receipt and Initial Installation
Receipt
International Environmental Corporation fan coil units
represent a prudent investment oering trouble-free
operation and long service with proper installation,
operation, and regular maintenance.
Your equipment is initially protected under the
manufacturer’s standard warranty; however, this
warranty is provided under the condition that the steps
outlined in this manual for initial inspection, proper
installation, regular periodic maintenance, and everyday
operation of the equipment be followed in detail. This
manual should be fully reviewed in advance before initial
installation, start-up, and any maintenance. Should
any questions arise, please contact your local sales
representative or the factory BEFORE proceeding.
The equipment covered by this manual is available with a
variety of options and accessories. Consult the approved unit
submittals, order acknowledgement, and other manuals for
details on unit options and accessories.
NO ATTEMPT SHOULD BE MADE TO HANDLE, INSTALL,
OR SERVICE ANY UNIT WITHOUT FOLLOWING SAFE
PRACTICES REGARDING MECHANICAL EQUIPMENT.
The equipment must always be properly supported.
Temporary supports used during installation or service
must be adequate to hold the equipment securely.
All power must be disconnected before any installation
or service is attempted. More than one power source
may be supplied to a unit. Power to remote mounted
control devices may not be supplied through the unit.
Never wear bulky or loose tting clothing when working
on any mechanical equipment. Gloves should be worn
for proper protection against heat and other possible
injuries. Safety glasses or goggles should always be
worn when drilling, cutting, or working with chemicals
such as refrigerants or lubricants.
Never pressurize any equipment beyond specied test
pressures. Always pressure test with an inert uid or gas
such as clear water or dry nitrogen to avoid possible
damage or injury in the event of a leak or component
failure during testing.
Always protect adjacent ammable material when
welding or soldering. Use a suitable heat- shield
material to contain sparks or drops of solder. Have a re
extinguisher readily available.
The manufacturer assumes no responsibility for personal
injury or property damage resulting from improper or
unsafe practices during the handling, installation, service, or
operation of any equipment.
Unpacking and Inspection
All units are carefully inspected at the factory throughout
the manufacturing process under a strict detailed quality
assurance program, and, where possible, ALL major
components and sub-assemblies are carefully tested for
proper operation and veried for full compliance with factory
standards. Operational testing of some customer-furnished
components such as electronic control valves and digital
controllers may be a possible exception.
Each unit is carefully packaged for shipment to avoid damage
during normal transit and handling. Equipment should
always be stored in a dry place, and in the proper orientation
as marked on the carton.
All shipments are made F.O.B. factory and is the responsibility
of the receiving party to inspect the equipment upon arrival.
Any obvious damage to the carton and/or its contents should
be recorded on the bill of lading and a claim should be led
with the freight carrier.
After determining the condition of the carton exterior,
carefully remove each unit from the carton and inspect
for hidden damage. At this time, check to make sure that
“furnished only” items such as thermostats, grilles etc. are
accounted for whether packaged separately or shipped at
a later date. Any hidden damage should be recorded and
immediately reported to the carrier and a claim should be
led. In the event a claim for shipping damage is led, the
unit, shipping carton, and all packing must be retained for
physical inspection by the freight carrier. All equipment
should be stored in the factory shipping carton with internal
packing in place until installation.
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Modular Hi-Rise Series Fan Coils
INSTALLATION, OPERATION, & MAINTENANCE MANUAL

At the time of receipt, the equipment type and arrangement
should be veried against the order documents. Should
any discrepancy be found, the local sales representative
should be notied immediately so that proper action may
be taken. Should any questions arise concerning warranty
repairs, the factory must be notied BEFORE any corrective
action is taken. Where local repairs or alterations can be
accomplished, the factory must be fully informed of the
extent and expected cost of those repairs before work is
begun. Where factory operations are required, the factory
must be contacted for authorization to return equipment and
a Return Authorization Number will be issued. Unauthorized
return shipments of equipment and shipments not marked
with an authorization number will be refused. In addition,
any claims for unauthorized expenses will not be accepted by
the manufacturer.
Handling and Installation
The units covered in this manual are identied by a tag on
top of the unit which shows the oor and riser number for
which each unit is designed. Units should not be installed at
locations other than that marked on the unit identication
tag. If no specic detail is shown on tag for unit location
then determine conguration for the Universal unit based
on information within this IOM. Should any questions arise
regarding unit conguration, contact the sales representative
or the factory BEFORE proceeding.
While all equipment is designed and fabricated with sturdy
materials and may present a rugged appearance, great care
must be taken to assure that no force or pressure be applied
to the coil, risers, or piping during handling. Never use the
risers to lift the unit. Also, depending on the options and
accessories, some units could contain delicate components
that may be damaged by improper handling. Lifting or
supporting the cabinet only at the top and bottom should
be avoided to maintain the straight and square cabinet
alignment. The unit must be lowered into the space taking
care to properly align the risers to engage the riser swaged
sections on the unit below. The risers should never be bent
or pushed together to be passed through the oor slot and
should never be lifted up or pulled down to meet the risers
on the oor below or above. The risers are designed with a
three-inch swage to accommodate a two-inch overlap and
minor oor to oor variations.
The equipment covered in this manual IS NOT suitable
for outdoor installations. The equipment should never be
stored or installed where it may be subjected to a hostile
environment such as rain, snow, or extreme temperatures.
During and after installation, special care must be taken to
prevent foreign material such as paint, plaster, and drywall
dust from being deposited in the drain pan or on the motor
or blower wheels. Failure to do so may have serious adverse
eects on unit operation, and in the case of the motor and
blower assembly, may result in immediate or premature failure.
All manufacturer’s warranties are void if foreign material is
allowed to be deposited on the motor or blower wheels of any
unit. Some units and/or job conditions may require some form
of temporary covering during construction.
While the manufacturer does not become involved in the
design and selection of support methods and components,
it should be noted that unacceptable system operating
characteristics and/or performance may result from improper
or inadequate unit structural support. Due to variations in
building construction, oor plans, and unit congurations,
each installation is dierent. The actual step-by-step method
of installation may vary from unit to unit. However, the risers
should be moved as little as possible to avoid damage to the
unit and internal components.
On certain units, shipping screws or braces must be removed
after the unit is installed. Be sure to check all tags on the
unit to determine which, if any, of these devices need to be
removed.
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Modular Hi-Rise Series Fan Coils
INSTALLATION, OPERATION, & MAINTENANCE MANUAL

SECTION II – Product Line Specic Installation
Part 1 – Universal Hi-Rise Units (MUY)
The unique design of the Universal Modular Fan Coil unit
allows for eld conguration for each unit. Air discharge,
riser, drain, and outside air knockouts have been strategically
located on each unit. Risers, shown with unit, are for
reference only. All risers are factory fabricated and shipped
loose for eld installation.
It is important that you identify all of the unit feature
locations and which knockouts you intend to use before
proceeding with the installation. Also, it must be determined
whether your application requires a Mating Unit (primary/
secondary) and its conguration. Consult your local sales
representative or the factory for further details on primary/
secondary arrangements.
Potential Unit Congurations
Risers: Three Locations–The pre-installed Supply, Return, and
Drain risers (2-pipe or 4-pipe applications) can be oriented on
any of three sides of the unit (see Figure 1).
NOTE: Risers can not be installed on the Return Air side of the
cabinet.
MUY
Cabinet
Return Air
HR CRDHS CS
HR CRDHS CS
HR CRDHS CS
D
CRHSCS
HR
R
D
S
HR = Hot Water Return
HS = Hot Water Supply
D = Drain
CR = Cold Water Return
CS = Cold Water Supply
R = Return
D = Drain
S = Supply
2- or 4-pipe
Figure 1
Unit orientation is determined based on the location of the
risers in the building. The riser side of the Universal Modular
unit always determines the rear of the unit (see Figure 2).
Return Air: Single Location–The Return Air/Access panel
may then be oriented on the left, right, or front of the unit.
Supply Air: Five Locations (4 sides and top) includes
stitched design for 1/2” duct anges.
Outside Air: Two Locations–Either side adjacent to the
Return Air opening.
NOTE: Outside Air opening may not be used on a side if risers are
configured on that same side.
Unit Knockout Locations (Typical)
Side Supply Air
Knockout
(1 per side)
Riser Knockouts
(4 per side,
except on
Return Air side)
Drain Knockout
(1 per side,
except on
Return Air side)
Outside Air
Knockout
(2 sides only,
adjacent to
Return Air
opening)
SIDE VIEW
Return
Air
Optional
Electrical
Knockouts
Figure 3A
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Modular Hi-Rise Series Fan Coils
INSTALLATION, OPERATION, & MAINTENANCE MANUAL

Top Supply
Air Knockout
TOP VIEW
Electrical
Knockouts
Figure 3B
Knockout
Slot
Knockout
Tab
KNOCKOUTS:
Knockout
Knockout
Tab
Drain
Knockout
Supply and Return
Figure 4
Drain
Insulation
Cut Line
Supply and Return
Insulation Cutline
Figure 5
Supply, Return, and Drain Riser Installation
1. Three sides of each Universal Modular unit have four
Supply and Return riser knockouts along the center
and one Drain knockout near the lower part of the unit
(see Figure 3A). Identify whether your application uses a
2-pipe or 4-pipe conguration.
a. 2-pipe congurations: typically use the two inner
riser knockouts.
b. 4-pipe congurations: will use all four riser
knockouts.
2. Locate and mark the riser and drain knockouts that
apply to your particular unit application, insuring proper
orientation of the Return Air opening in room.
3. Insert a at head screw driver into knockout slot shown in
Figure 4.
4. Pry screw driver back and forth until knockout tabs break
away from the unit.
5. Discard knockout. Be careful of sharp edges.
6. Use a sharp retractable knife (see Figure 5) and vertically
cut the insulation down the center of the riser and drain
knockouts the full length of the knockout.
7. Use adhesive or glue to re-attach insulation that has
pulled away from the unit during knockout removal
process.
CAUTION: Toxic residues and loose particles
resulting from manufacturing and eld piping
techniques such as joint compounds, soldering
ux, and metal shavings may be present in the
unit and the piping system. Special consideration must be
given to system cleanliness when connecting to solar,
domestic or potable water systems.
Submittals and product literature detailing unit operation,
controls, and connections should be thoroughly reviewed
BEFORE beginning the connection and testing of risers and
piping.
To assure optimal unit performance, the supply connection(s)
are marked on the unit’s coil with an “S” meaning supply or
inlet and “R” meaning return or outlet indicating ow direction
to and from the coil. Blue letters mark the chilled water
connections and red letters mark the hot water connections.
The unit’s internal piping is designed to accommodate a total
riser vertical movement of ±1-1/2”, due to thermal expansion
and/or contraction, when positioned properly at the job site.
Risers must be anchored to the building structure to limit
expansion and contraction movement to a maximum of 3”.
Riser anchoring and expansion
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Modular Hi-Rise Series Fan Coils
INSTALLATION, OPERATION, & MAINTENANCE MANUAL

compensation is not included in the unit and must be
provided. Riser end caps, air vents, and/or ushing loops
must be provided at the jobsite by the installer.
Proper eld riser installation and vertical positioning in the
unit should have a pipe run-out to the service valves which
are centered in the knockout access slots and that slope
down slightly away from the riser (see Figure 6). This prevents
condensation from running back to the riser and possible
damage from dripping at the bottom of a riser column.
Each job has specic requirements and satisfying those
requirements is the responsibility of the installer.
Riser to Unit Installation
Ball
Valve
Riser Stubout
Insulation
Threaded
Fitting
Unit insulation
Outer
Cabinet
Riser Knockout
Slot
Figure 6
Before making the riser joints, the riser insulation must be
pulled back away from the joint and protected from heat
during the brazing process. Each riser joint must be in vertical
alignment. Variations in oor-to-oor dimensions may
require eld work such as cutting o or extending the risers.
This operation is the responsibility of the installer. The riser
joint ller material must be selected to withstand the total
operating pressure (both static and pumping head) to which
the system will be subjected. Low temperature lead alloy
solders such as “50/50” and “60/40” are normally not suitable.
Flexible
Hose Kit
Riser
Ball
Valve
Riser Stubout
Insulation
Bae
Connection point to any factory
furnished and installed
components.
Coil
Figure 7
Back-up
Wrench
Ball
Valve
Wrench
Swivel
Connection
Figure 8
Riser to Drain Installation
Drain Pan
Drain
Clamp
Clamp
Riser Knockout
Unit Insulation
P-Trap
Unit Wall
Riser
Riser Stubout
Figure 9
1. After the applicable Supply, Return, and Drain knockouts
have been removed, carefully position the unit so that
the riser ball valves penetrate into the unit through the
riser knockouts making sure the insulation penetrates
into the unit as shown in Figures 6, 7, and 9.
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Modular Hi-Rise Series Fan Coils
INSTALLATION, OPERATION, & MAINTENANCE MANUAL

2. Before anchoring the equipment in place, the unit must
be leveled and the cabinet must be plumb and squared.
The unit may be anchored in place by bolting directly
through the unit oor or attaching to the cabinet in
some location that will not interfere with drywall or
other items such as the supply grille, thermostat, or
return access panel. When attaching to the unit cabinet,
care must be taken to not penetrate the cabinet in
locations that may damage internal components or
wiring. The mounting technique is a matter of choice;
however, the unit should always be anchored securely
to prevent movement during construction and riser
expansion and contraction.
After anchoring the unit, it is then ready for the various
service connections such as riser connections and
electrical.
3. The plastic are caps on the end of the riser ball valves
should be removed and discarded.
4. All Universal Modular units use reinforced braided
stainless steel exible hose kits for piping between eld
installed risers and unit water coils as shown in Figure 7.
The hose kit design has threaded connections on each
end. The hose kits allow for riser uctuations due to
thermal expansion.
5. Use a wrench to tighten the swivel connections. Use a
backup wrench to hold the riser ball valve stationary to
prevent it from bending or twisting during installation as
shown in Figure 8. Be careful to not over tighten swivel
connections.
CAUTION: Hose connection torque
requirements are 350 in. lbs. +10/-0 in. lbs. to
prevent leaks.
6. Locate the unit’s coil tting.
7. The plastic are caps on the end of the coil tting should
be removed and discarded.
8. Use a wrench to tighten the swivel connections. The
bae acts as a secondary wrench. Be careful to not over
tighten swivel connections.
CAUTION: Hose connection torque
requirements are 350 in. lbs. +10/-0 in. lbs. to
prevent leaks.
9. Locate the p-trap drain and rubber hose factory installed
to the drain pan connection in the bottom of the unit as
shown in Figure 9.
10. Push the rubber drain hose over the riser drain stubout.
Be careful that you do not bend the drain stubout.
11. Adjust the hose clamp over the riser stubout and rubber
hose to hold in place as shown in Figure 9.
12. Test for leaks. Any and all leaks should be repaired before
proceeding with installation. When testing with air or
some other gas, it might be necessary to tighten stem
packing nuts on some valves to maintain air pressure
in the riser. Pressure testing risers with water should
be done with the unit service valves closed to prevent
ushing debris into the unit valve packages. This will
also allow risers to be drained down after testing in
the winter to avoid freeze-up problems. In the event
that leaking or defective components are discovered,
the sales representative must be notied BEFORE any
repairs are attempted. All leaks should be repaired
before proceeding with the unit installation.
13. After system integrity has been established, the riser
insulation must be pulled back into place over the joint
and glued or sealed to prevent sweating and heat loss or
gain. All of the risers including the riser stubouts should
be properly covered with insulation. Internally mounted
chilled water piping and valves are located over the drain
pan and need not be insulated.
Any reproong requirements where risers or piping
penetrate oors or walls are the responsibility of the
installer. This work should be done only after all pressure
testing is completed. The reproong method used must
accommodate pipe expansion and contraction and the
piping must be protected from abrasion and chemical attack.
The pipe insulation also must be maintained to prevent
sweating and must be protected from wear or erosion at the
joint between the insulation and the reproong material.
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Modular Hi-Rise Series Fan Coils
INSTALLATION, OPERATION, & MAINTENANCE MANUAL