owner’s manual
Packaged Hydronic/Steam
Make-up Air Systems
CAUTION: Read all instructions carefully before starting installation.
A Division of:
14716 S. Broadway, Gardena, CA 90248 • Tel: (800) 421-1266 • (310) 532-1555 • Fax (310) 324-3030
Internet: www.marsair.com • Email:
Form #HSMAS0312
ARES products meet the stringent listing or certification requirements of many organizations.
The specifics vary depending on the model, options installed or application usage. ARES
reserves the right to make improvements and changes to specifications without notice.
Packaged Hydronic/Steam Make-Up Air Unit
Tel: (800) 421-1266 • Internet: www.marsair.com 2
Contents
General Information 2
Preliminary Installation Procedures 3
Installation Procedure 5
Hoisting Eye Installation 5
Ductwork Installation 5
Ceiling Register Installation 5
Water Installation 6
Electrical Controls 7
Coil Assembly 8
Optional Accessories 9
Trouble-Shooting Chart 11
ARES Preventative Maintenance Procedures 12
Wiring Diagrams 13
Parts List 16
Service and Ordering Information 17
Limited Warranty 18
Owner Registration 19

fans, plumbing stacks, and any other equipment where unwanted odors or materials may be drawn
into the system. Insure these minimum separations are maintained.
3. Make sure all electrical rough-ins, disconnects and power supplies are installed according to local
jurisdiction.
4. Make sure plumbing is clearly understood and according to local codes.
5. Some areas require seismic restraints to be applied when Make-Up Air Units are installed. Check
with local authorities to make sure these applications are in compliance.
6. Refer to the installation section to determine the operating weight of the ARES unit being installed.
Check with person responsible for determining roof loads prior to setting this equipment.
The following items should be discussed with the installing contractor. Make sure all loose items are
accounted for prior to installation.
1. If items are found missing, contact ARES Service Department immediately at (800-421-1266).
2. Make sure all electrical service requirements are fully understood prior to installation procedure.
3. Make sure all plumbing service requirements for incoming gas piping are understood prior to
installation.
4. Make sure all field joints for ducting are fully understood prior to installation.
5. Recheck equipment for any damage when may have occurred prior to installation. Any noted
problems should be reported to ARES Service Department immediately at (800-421-1266).
6. Make sure all clearances noted in the installation procedure are complied with when equipment is
being placed.
CAUTION: Failure to do so may result in assemblies not having adequate
clearance for removal and service.
7. Make sure hoisting equipment is of sufficient size to adequately lift equipment into place during
installation.
Packaged Hydronic/Steam Make-Up Air Unit
Tel: (800) 421-1266 • Internet: www.marsair.com 4
THE FOLLOWING ITEMS SHOULD BE DISCUSSED WITH THE SHEET METAL
CONTRACTOR
1. Make sure all duct size and layout procedures are fully understood.
2. Make sure turning vanes are installed wherever necessary.

Position the hoisting eyes on corners of the unit with the angle towards the
center of the unit. (See illustration at right)
Run the bolt through the unit housing and hoisting eye, then attach the nut.
(See illustration at right).
DUCTWORK
1. Sizing and layout of ductwork and outlets should provide maximum uniform airflow throughout the
area. Make-up air should be introduced at a location inside the area, but as far away from existing
exhaust hoods as possible to permit conditioned air to flow throughout the entire area before
reaching the exhaust zone, or unless connected to an engineered make-up air system.
2. Ductwork must be adequately sized and
designed for minimum resistance (static
pressure) to provide required airflow. Check
rating plate for minimum allowable CFM flow
over the heat exchange: at low heating
speed.
3. To avoid pressure losses, all short radius
rectangular elbows should have turning
vanes, offsets should not be avoided, and
small ducts and takeoffs should be
undersized.
4. Main supply duct normally consists of a
rectangular vane elbow at the unit and
vertical duct extension, both pieces having
the same dimensions as the unit discharge
opening. The ductwork gauge size must be
according to local codes. Ceiling registers
should be the fixed type (if adjustable, modify
so full closing is not possible). (See
illustration right)
CEILING REGISTER

local codes).
5. Install the float valve assembly and adjust it so the water level is approximately 2" deep in the sump
pan. (See illustration below).
CAUTION: Damage caused by incorrect water level in sump pan is not covered
by the ARES warranty.
6. Install the float valve and adjust the bleed valve to bypass the main water line to rid the system of
organic and mineral deposits. (See illustration above)
Packaged Hydronic/Steam Make-Up Air Unit
ELECTRICAL CONTROLS
COOL Actuates blower motor relay and (optional) pump relay if evaporative cooling is
purchased.
VENT Actuates blower motor relay only.
HEAT Actuates blower motor relay and (optional) steam valve motor with proportional control.
If optional steam valve/liquid valve and control are not ordered, a dry set of contacts will
be provided to allow signaling of an external control by others.
HI-LO Actuates either high or low blower motor relay dependent upon selected
(Optional) switch position.
RETURN AIR Actuates damper for outside air or recirculates inside air.
(Optional)
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Packaged Hydronic/Steam Make-Up Air Unit
Tel: (800) 421-1266 • Internet: www.marsair.com 8
COIL ASSEMBLY
UNIT SELECTION INFORMATION
For Steam:
1. Furnish CFM, external static pressure, entering air temperature, leaving air temperature, steam
pressure (and temperature if super-heated).
2. Select options.
For Hot or Cold Water
1. Furnish CFM, external static pressure, entering air temperature, leaving air temperature, water

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OPERATION
INITIAL START-UP
1. Check electrical power and manifold pressure against the unit’s nameplate.
2. Check airflow through the unit.
a. The adjustable motor sheave should be adjusted to provide the correct blower wheel RPM
to attain the design airflow at the inherent system resistance. Do not adjust sheaves so the
airflow is below the minimum shown on the nameplate.
b. Be certain the installation is adjusted to obtain the temperature rise specified on the
nameplate.
3. Check belt tension and alignment. Correct tension is a center belt deflection of 1/2" and 3/4" for
each foot of belt between the pulley and sheave.
CAUTION: Never adjust the belt tension by changing the setting of the split
motor sheave. Adjust by moving electric motor along tracks provided on the
motor base to obtain correct fan belt deflection.
4. Check nameplate for maximum amperage.
5. With an observer at the unit, complete the following at the remote control panel:
a. Assure power is on. Set unit on high speed (two speed units only).
b. Push “Vent” button. Blower should operate.
c. Using an ampmeter, test motor amperage and adjust as required with adjustable sheave.
Be sure load on motor does not exceed nameplate amperage rating.
d. Push “Cool” button. Pump and blower should be in operation.
e. Push “Heat” button. The blower will remain in operation and the steam/liquid valve will be
activated.
f. On two speed models, place the 2-speed toggle switch in desired (high or low) position.
g. Push “Off” button. Unit should shut down.
6. Check discharge air control for desired temperature setting. (Field provided on Hydronic units.)
7. If unit is operating properly, recheck system by repeating Step 5. If unit does not function properly,
refer to Troubleshooting and Service Section.
Packaged Hydronic/Steam Make-Up Air Unit

a. 24 volt power to switch
b. With switch set at its various positions, check output voltage per the switch action shown in
the wiring diagram on unit.
7. If there is mineral buildup on evaporative pads, check:
a. Insufficient bleed off water
b. Bleed line plugged
c. Insufficient water over pads (hardness of water may necessitate more frequent cleaning
and/or pad replacement).
Packaged Hydronic/Steam Make-Up Air Unit
Tel: (800) 421-1266 • Internet: www.marsair.com 12
ARES Preventative Maintenance Procedures
MAINTENANCE ITEMS QUARTERLY HEATING SEASON COOLING SEASON
STANDARD EVAPORATIVE COOLERS
Evap/filter media
Check and clean. Check and clean. Check and clean.
Replace if necessary.
Replace every 5 yrs.
Evap pump/basket
Clean before start
of season.
Check for operation.
Evaporator pan
Check and clean. Drain and clean. Clean and fill.
Float valve assembly
Check operation. Turn off water supply. Turn on water and
check for proper
adjustment, 2" in pan.
Bleed off valve
Check for clogging. Assure proper
placement in drain

Check corrosion
& leaks.
Ensure drain valve
opens, draining pan.
Ensure fill valve opens,
filling pan.
Packaged Hydronic/Steam Make-Up Air Unit
Tel: (800) 421-1266 • Internet: www.marsair.com 13
NOTE: IF ANY OF THE ORIGINAL WIRE AS
SUPPLIED WITH THE APPLIANCE MUST BE
REPLACED, IT MUST BE REPLACED WITH
WIRING MATERIAL HAVING A TEMPERATURE
RATING OF AT LEAST 105 ∞C.
FIELD HI VOLT
FIELD LO VOLT
FACTORY HI VOLT
FACTORY LO VOLT
NOTE: IF ANY OF THE ORIGINAL WIRE AS
SUPPLIED WITH THE APPLIANCE MUST BE
REPLACED, IT MUST BE REPLACED WITH
WIRING MATERIAL HAVING A TEMPERATURE
RATING OF AT LEAST 105 ∞C.
FIELD HI VOLT
FIELD LO VOLT
FACTORY HI VOLT
FACTORY LO VOLT
H1 & H2 TERMINALS ARE DRY
CONTACTS THAT CLOSE DURING
THE "HEAT" CYCLE.
NOTE: IF ANY OF THE ORIGINAL WIRE AS

FIELD LO VOLT
FACTORY HI VOLT
FACTORY LO VOLT
Packaged Hydronic/Steam Make-Up Air Unit
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Packaged Hydronic/Steam Make-Up Air Unit
Tel: (800) 421-1266 • Internet: www.marsair.com 16
ARES Parts List
PART NO. DESCRIPTION
987060 Motor base
990065 Pump CP6500
980390 Pump basket
981665 Float valve
987400 Pad frame assembly
987360 Coolpad filer 36" X 34"
989635 Blower assembly 15 X 15
990715 Blower assembly 18 X 18
986400 1/2 HP 115/230V, 1 phase, 1 speed
986405 1/2 HP 208/230-460V, 3 phase, 1 speed
986410 1/2 HP 115V, 1Phase, 2 speed
986420 1/2 HP 115/230V, 1 phase, 1 speed
986425 1/2 HP 208/230-460V, 3 phase, 1 speed
986430 1/2 HP 115V, 1 phase, 2 speed
986435 1/2 HP 230V, 1 phase, 2 speed
986450 1 HP 115/230V, 1 phase, 1 speed
986460 1 HP 115V, 1 phase, 2 speed
986465 1HP 230V, 1 phase, 2 speed
986470 1 HP 208/230V, 3 phase, 2 speed
986475 1 HP 460V, 3 phase, 2 speed
986455 1 HP 208/230-460V, 3 phase, 1 speed

question is returned, inspected and found defective under normal usage (call the Service Department
at ARES
®
for instructions).
2.TERMS AND CONDITIONS
Price changes: All prices will be shipped C.O.D. for customers without an open account.
Returns: Written authority must be obtained before returning any merchandise. All returned
merchandise must be shipped prepaid and is subject to a handling charge.
Damaged merchandise: Notify the carrier in the event of damaged shipments, whether apparent at the
time of delivery or concealed damage is discovered after unpacking. File your complaint with the
carrier, not the factory. ARES’ responsibility ceases when shipment is accepted by a reliable carrier for
delivery.
Taxes: Any taxes or other government charge upon production, sale and/or shipment of merchandise
sold hereunder, not imposed by Federal, State, or Municipal authorities, or hereafter becoming
effective, shall be added to the price herein provided, and shall be paid by the buyer.
ALL SHIPMENTS F.O.B., GARDENA, CALIFORNIA
TO ORDER PARTS OR OBTAIN SERVICE INFORMATION, CONTACT:
AIR REPLACEMENT ENGINEERING SYSTEMS
14716 S. Broadway
Gardena, CA 90248
Phone: (800) 421-1266
Fax: (310) 324-3030
Packaged Hydronic/Steam Make-Up Air Unit
Tel: (800) 421-1266 • Internet: www.marsair.com 18
Limited Warranty
Packaged Hydronic/Steam Make-Up Air Unit
Model No.:_____________________________Serial No.:_________________________________
Voltage:______________Phase:_________Steam:______________Hydronic: ________________
Date Installation Completed: ____________________________________
ARES

90248. Phone: 800-421-1266; fax: 310-324-3030 or by email at;
What to do in case of unsatisfactory warranty service.
Please write the ARES
®
Service Department. Include your name, address and zip code, name of
agency from whom unit was purchased, the model and serial number of the unit, date of purchase and
a description of the problem.
Any warranty that may be implied from this purchase is hereby limited to the one year duration of this
warranty. Some states do not allow limitations on how long an implied warranty lasts, so the above
limitation may be apply for you.
This warranty gives you specific legal rights, and you may also have rights which may vary from state
to state.
Parts may be ordered from the ARES Service Dept. by contacting by phone at 800-421-1266. You may
also contact us by fax at 310-324-3030 or by email at
Packaged Hydronic/Steam Make-Up Air Unit
Tel: (800) 421-1266 • Internet: www.marsair.com 19
OWNER REGISTRATION
REFERENCE SHEET
For
Packaged Make-up Air Units
(fill out at time of installation)
DO NOT REMOVE FROM THIS MANUAL
Model No.__________________________ Serial No. _______________________
Customer’s Name____________________________________________________
Address____________________________________________________________
Installer’s Name _____________________________________________________
Address____________________________________________________________
Installed at _________________________________________________________
Installation Date _____________________________________________________
Remarks ___________________________________________________________

Are set screws and locking collars tight Yes ______ No _______
Unusual wheel alignment or vibration Yes ______ No _______
Is coil positioned and piped properly Yes ______ No _______
Are evaporative pads working properly (if supplied) Yes ______ No _______
Are unit bases properly installed Yes ______ No _______
System operational without further adjustment Yes ______ No _______
System requires following corrections:__________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
System demonstrated to System inspected by
____________________________________ ____________________________________
____________________________________ ____________________________________
____________________________________ ____________________________________
Packaged Hydronic/Steam Make-Up Air Unit
Tel: (800) 421-1266 • Internet: www.marsair.com
ARES
14716 South Broadway
Gardena, CA 90248
ATT: WARRANTY DEPT
Place
Postage
Here