Bard Q-TEC Q A4D Series User manual

Literature Assembly
911-0838
Contains the following:
2100-034 (G) User Guide
2100-479 Leak Test Evacuation Charging
2100-752(C) Q24-42A4 Installation Instructions
2110-1568 (G) Replacement Parts Manual
7960-923 Dehum Supplemental Manual QA
7960-420 Warranty

Climate Control Solutions
BARDHVAC.COM
Bard Manufacturing Company, Inc.
Bryan, Ohio 43506
www.bardhvac.com
Manual: 2100-034G
Supersedes: 2100-034F
Date: 12-17-20
USER’S APPLICATION
GUIDE AND TECHNICAL
PRODUCT OVERVIEW

Manual 2100-034G
Page 2 of 21
General Information
The User's Application Guide covers a wide range of heating and cooling products manufactured by Bard
Manufacturing Company. It is intended to be a general guide for care and operation of typical systems and covers the
most important features you should be aware of and are responsible for as the user of the equipment.
Because our product offerings are so varied and can be equipped with many features and options, it is not possible to
cover all aspects of what your specic system may be congured for. Some systems may be quite simple in features to
provide basic cooling and possibly heating, while other systems may also incorporate various ventilation technologies,
dehumidication circuits and many different internal controls as well as room temperature controls. Therefore, you
should request a detailed operation sequence and explanation of any special features from your installer and/or service
company and also have them instruct you as to any routine maintenance procedures you are responsible for.
Contents
Overview ........................................................................3
Documentation .............................................................4
Unit Literature Assembly – Documentation Provided
with Your Units .....................................................4
Unit Installation ...........................................................5
WALL MOUNT Products – Mounting the Product on
Wall Surface .........................................................5
WALL MOUNT Products – Clearances for Outdoor
Condenser Fan Airow ...........................................6
WALL MOUNT Products – Clearances for Indoor
Supply and Return Airow......................................6
WALL MOUNT Products – Condensate and Defrost
Drainage ..............................................................7
I-TEC and Q-TEC Products – Installing the Product
Inside a Room ......................................................8
I-TEC and Q-TEC Products – Clearances for Outdoor
Condenser Fan Airow ...........................................8
I-TEC and Q-TEC Products – Clearances for Indoor
Supply and Return Airow......................................9
I-TEC Air Path................................................9
Q-TEC Air Path...............................................9
I-TEC and Q-TEC Products – Condensate Drainage .10
All Products – Power Supply Verication................11
Field-Supplied Voltage ..................................11
Single and Three Phase Power .......................11
Hertz (Frequency).........................................11
Unit Maintenance .......................................................12
All Products – Filters and Filter Servicing ..............12
Outdoor Unit Wall Mount Room Air Filters.......12
WALL MOUNT Products – Filters and Filter
Servicing............................................................13
I-TEC Indoor Products – Filters and Filter
Servicing............................................................14
Q-TEC Indoor Products – Filters and Filter
Servicing............................................................15
All Products – Coil Cleaning .................................16
Equipment Corrosion Protection.....................16
All Products – Condenser Airow ..........................17
Unit Operation ............................................................18
Air-to-Air Cooling Products (Air Conditioners) .........18
Air-to-Air Cooling and Heating Products
(Heat Pumps) .....................................................18
Cooling Mode ...............................................18
Heating Mode ..............................................18
Water-to-Air Cooling and Heating Products
(Geothermal Heat Pumps)....................................19
Cooling Mode ...............................................19
Heating Mode ..............................................19
Water Supply Systems...................................19
Dehumidification and Ventilation Operation.......20
Dehumidication (Air-to-Air or Water-to-Air
Systems) ............................................................20
Ventilation Options (Air-to-Air or Water-to-Air
Systems) ............................................................20
Troubleshooting .........................................................21
All Units – Troubleshooting ..................................21

Manual 2100-034G
Page 3 of 21
Overview
The User's Application Guide and Technical Product Overview covers the following products:
WALL MOUNT
Air Conditioners
and Heat Pumps
I-TEC®
Air Conditioners
and Heat Pumps
Q-TECTM
Air Conditioners
and Heat Pumps
The User's Application Guide and Technical Product Overview covers the following topics:
• Documentation provided by Bard for proper use of your new product.
• Unit installation guidelines.
• Routine unit maintenance.
• Unit operation.
• Unit troubleshooting.
Please use this guide as a general overview regarding unit application, maintenance and troubleshooting. Refer
to product installation instructions and supplemental documentation provided with the unit or go to
www.bardhvac.com for detailed individual product information.
Overview

Manual 2100-034G
Page 4 of 21
Documentation
There are two sources of valuable information for your new Bard product:
• Documentation provided with your unit, normally located inside the unit control panel during shipping. This
information should be saved once the unit is installed for future maintenance reference or to answer questions
about equipment after installation.
• Documentation provided on the internet at www.bardhvac.com. This may be accessed from a desktop computer
at the ofce, a laptop or an internet-capable cell phone at the worksite. Up-to-date documentation is available,
along with specication sheets and other valuable resources regarding your new Bard product.
Unit Literature Assembly – Documentation Provided with Your Unit
Bard products are shipped with documentation that when used by a technician with cooling and heating knowledge,
can ensure that your product is installed safely, performs optimally and achieves the longest life cycle possible.
Shipped literature includes the following:
• User Manual (this document)
• Installation Instructions
• Replacement Parts Manual
• Wiring Diagrams
• Warranty Information
Documentation

Manual 2100-034G
Page 5 of 21
Unit Installation –Wall Mount
Unit Installation
Installation plays a key part in unit functionality, performance and safety. Product securing and placement, duct
design and supply/return location, electrical routing and condensate and defrost drainage all play key roles in making
sure a unit will perform per the design specications.
WALL MOUNT Products – Mounting the Product on a Wall Surface
Outdoor products are normally mounted to an exterior wall surface, including brick,
cement block, metal or wood construction. These products are labeled as “WALL
MOUNT” units. Before installation begins, the wall surface should be inspected by a
construction professional to ensure it will support the weight of the unit and accessory
items. Approximate weights are available from the product specication sheet, and a
safety factor should be designed into the installation. Typical fasteners to attach the unit
to the wall using the integrated mounting anges on both sides of the unit include tap
cons, bolts, studs and other fastening devices. The selection of the fasteners to be used
needs to be reviewed by a construction professional and decided upon based on the wall
construction and fastener strength required. It is important to follow all guidelines and
procedures covered in the installation instructions manual provided for the product.
Built-In Mounting Flange Detail:
Outdoor WALL MOUNT products include a
mounting flange that is part of the cabinet
construction. Ø.375" holes are provided for
unit mounting unless specified otherwise in
installation instructions.
Specification Sheets:
Unit specification sheets provided at
www.bardhvac.com include basic unit weights and
dimensions (see example below). Ventilation options and
other accessories must be added into the total weight of
the unit.
Specification Sheet Example

Manual 2100-034G
Page 6 of 21 Unit Installation –Wall Mount
WALL MOUNT Products – Clearances for Outdoor Condenser Fan Airflow
Unit placement and avoidance of obstructions outside the structure are very critical to unit performance. Avoid
installing the unit in areas that will obstruct outdoor condenser fan airow or create “pockets” of heated air being
exhausted from the condenser coil. Solid construction fences should not be placed directly in front of the unit
without provisions for condenser airow. Solid exterior walls need to be spaced as far away from units as possible to
avoid pockets of heated air causing condenser air recirculation.
Solid barriers located too close to the face or side surfaces (condenser fan inlet and outlet) of the WALL MOUNT can
both impede airow and force heated air to short circuit (be returned) from the condenser outlet to the condenser
inlet. Either condition will effectively raise the condensing temperature and pressure reducing cooling capacity
and efciency. In extreme cases, the unit may fail to operate due to high refrigerant pressures inside the unit, and
compressor and/or fan motor failure may occur. Clearances given in installation instructions ensure components can
be serviced and maintenance can be performed when needed.
National and local electrical codes must be reviewed before unit installation.
Always use common sense when installing products, follow unit clearances given in the installation instructions
and contact local Bard distributors when additional knowledge is needed regarding unit clearances for proper unit
functionality.
WALL MOUNT Products – Clearances for Indoor Supply and Return Airflow
The Bard unit should be placed in an area where the supply (leaving conditioned air) and return (unit air intake)
air paths will be unrestricted. Avoid placing objects in the structure within 24" of the return (unit air intake) grille.
Avoid placing objects directly in the path of the supply (conditioned) air grille. This will inhibit the “throw” of the
supply air throughout the structure and reduce the cooling and/or heating ability of the unit; in extreme cases, this
may cause evaporator coil freezing issues. Supply air must be able to freely circulate conditioned air throughout the
structure. Adjustment of supply grille deectors is often necessary to ensure proper room circulation.
Ducted applications should not exceed the rated duct static pressures given in the unit specication sheets. Special
requirements for duct construction and distances to combustible materials need to be followed per the installation
instructions when electric heating is used.

Manual 2100-034G
Page 7 of 21
Unit Installation –Wall Mount
WALL MOUNT Products – Condensate and Defrost Drainage
Condensate Water Drainage:
Unit condensate water exits the base
of the unit during cooling operation.
Defrost Water Drainage:
Holes are provided in the front of the unit base for heat
pump condensate water drainage.
Defrost Water Drainage:
6" clearance is recommended under WALL MOUNT Heat
Pump products to allow proper defrost water drainage.
Condensate drainage for air conditioning units
needs to be planned before installation. Your
new Bard WALL MOUNT product includes
provisions to allow condensate water to exit the
bottom of the unit. If condensate water is to be
routed away from the unit, adequate drain sizing
needs to be provided to allow proper drainage
for condensate water generation. During normal
air conditioning operation, large amounts of
condensate water is generated inside the unit as
moisture is extracted from the supply air. This
is collected in an evaporator pan and drained
to either a drainage system (indoor products)
or outside the unit cabinet (outdoor products).
Evaporator drain traps are not necessary for any
of our wall mounted outdoor products, and the
use of “standing water” U-shaped traps may be
prone to freezing in certain climate zones.
Defrost water drainage from heat pump units
needs to be planned before installation. During
seasons requiring heating operation, the unit
will need to warm the condenser coil to remove
frost build-up (defrost). Outdoor heat pump
products include holes in the unit base under
the condenser coil for proper water drainage
when in the heating defrost cycle. Avoid placing
the unit on a pad or blocking the base drainage
holes under the condenser coil without proper
allowances (6" recommended) for water drainage
due to damage caused by freezing conditions.
Without proper drainage, defrost water may
freeze causing ice build up and damage the
lower portion of the condenser coil.

Manual 2100-034G
Page 8 of 21 Unit Installation –I-TEC and Q-TEC
I-TEC and Q-TEC Products – Installing the Product Inside a Room
Indoor products are normally supported by the oor surface and are adjacent to an interior
wall surface, including brick, cement block, metal or wood construction. These products
are normally labeled as “I-TEC” or “Q-TEC” units. Before installation begins, the oor
surface should be inspected by a construction professional to ensure it will support the
weight of the unit and accessory items. Approximate weights are available from the product
specication sheet, and a safety factor should be designed into the installation.
A sheet metal sleeve is normally installed in the wall allowing vent and condenser fan air
to enter and exit the unit. Different sleeve depths are available for installation into various
wall depths. Typical fasteners to attach the sleeve to the outside surface of the wall include
tap cons and other fastening devices. The I-TEC or Q-TEC unit is then slid up to the wall
surface and connected to the sleeve using screws. Trim kits are available to enclose gaps
between the wall surface and the unit. A louver grille is used to cover the external wall
opening and fasteners used during sleeve installation.
Wall Sleeve:
Wall sleeves allow for outdoor air
to enter and exit the unit inside
the room.
Air Paths:
Air paths through the unit allow for
cooling operation and fresh air to
enter the structure (I-TEC shown).
Louver Installation:
Outdoor louvers provide an esthetically
pleasing look to the installation and cover
the unit opening (I-TEC shown).
I-TEC and Q-TEC Products – Clearances for Outdoor Condenser Fan Airflow
Solid barriers located too close to the face of the outdoor louver of the I-TEC or Q-TEC can both impede airow and
force heated air to short circuit (be returned) from the condenser outlet to the condenser inlet. Either condition
will effectively raise the condensing temperature and pressure reducing cooling capacity and efciency. In extreme
cases, the unit may fail to operate due to high refrigerant pressures inside the unit, and compressor and/or fan motor
failure may occur. It is recommended to allow 15' (457.2 cm) in front of unit louver for proper condenser airow.
Always use common sense when installing products, follow unit clearances given in the installation instructions
and contact local Bard distributors when additional knowledge is needed regarding unit clearances for proper unit
functionality.
I-TEC
Q-TEC

Manual 2100-034G
Page 9 of 21
Unit Installation –I-TEC and Q-TEC
I-TEC and Q-TEC Products – Clearances for Indoor Supply and Return Airflow
Typical I-TEC Installation
Typical Q-TEC Installation
The Bard unit should be placed in an area where the
supply (leaving conditioned air) and return (unit air
intake) air paths will be unrestricted. Avoid placing
objects inside the room within 24" of the return (unit air
intake) louvers or grille. Avoid placing objects directly
in the path of the supply (conditioned) air grilles. This
will inhibit the “throw” of the supply air throughout the
structure and reduce the cooling and/or heating ability
of the unit and in extreme cases may cause evaporator
coil freezing issues. Ducted applications should not
exceed the rated duct static pressures given in the unit
specication sheets. Special requirements for duct
construction and distances to combustible materials
need to be followed per the unit installation instructions
when electric heating is used.
I-TEC Air Path
The I-TEC product has been engineered for extremely
quiet unit operation and has multiple air paths for
air entering and exiting the unit. Room air enters the
upper sides to be conditioned (cooled) inside the
unit and exits the unit top. The unit will either be
ducted to supply registers or have a supply air plenum
box installed. A supply air plenum box allows quiet
operation without ducting the air leaving the unit. Room
air also enters the bottom of both front doors during
ventilation operation.
Q-TEC Air Path
The Q-TEC product has been engineered for efcient,
economical unit operation and has a mid-mounted front
grille for air entering the unit. The unit will either be
ducted to supply registers or have a supply air plenum
box installed. A supply air plenum box allows quiet
operation without ducting the air leaving the unit.
The I-TEC and Q-TEC product installation instructions contain additional information regarding unit air paths
and required clearances. This information may be accessed at www.bardhvac.com.
Room air
enters unit
Cool
conditioned
air exits unit

Manual 2100-034G
Page 10 of 21 Unit Installation –I-TEC and Q-TEC
I-TEC Drain System:
The I-TEC drainage system consists of a manifold drain kit that combines all drains behind the unit to allow connection to
the building system.
Q-TEC Drain System:
The Q-TEC drainage system consists of a lower right side or lower right rear connection fitting. An optional in-wall drain box
may also be purchased as an accessory that allows separate evaporator and defrost water drainage.
Lower Right Side Drain Lower Right Rear Drain Optional In-Wall Drain Box
I-TEC and Q-TEC Products – Condensate Drainage
Condensate drainage for Bard indoor cooling units is a very important part of unit installation. During normal air
conditioning operation, large amounts of condensate water are generated inside the unit as moisture is extracted
from the supply air. This is collected in an evaporator pan and needs to be drained to an external drainage system.
Your new Bard product includes provisions to allow condensate water to exit the unit and ttings will need to be
eld supplied to connect the unit drain to the building. Adequate drain sizing needs to be provided to allow proper
drainage for condensate water generation and restriction in drain lines should be avoided. Evaporator drain traps are
not necessary unless required by local codes.
Defrost water for heat pump operation and outdoor water entering the condenser area also needs to be drained out of
the unit. The I-TEC product uses a combined defrost and outdoor water drainage system. The Q-TEC has a combined
defrost and evaporator drain connection unless an optional in-wall drain box is used. Outdoor water exits the
Q-TEC through the wall sleeve. Follow all instructions provided in the unit installation instructions regarding drain
connections and sleeve installation to avoid water leakage inside the building or structure.

Manual 2100-034G
Page 11 of 21
Unit Installation –Electrical
All Products – Power Supply Verification
It is very important to follow all electrical and mechanical safety guidelines and instructions provided in the product
installation instructions. Failure to do so may result in death, injury or product damage.
A proper power supply to your new Bard unit is very important. Be sure to verify the following with a multi-meter or
other power measuring device before applying power to your Bard product.
Field-Supplied Voltage
Electrical voltage ratings and proper voltage operating ranges are provided in the unit specication sheets and
installation instructions. It is important that power supplied to the unit stay in the specied operating voltage range.
Voltage above or below the minimum operating value given could result in improper unit startup, unit shutdown,
low unit performance, improper thermostat and unit controller operation, compressor damage and premature failure
of functional parts. As a general guideline, it is always best if the power source for the unit supplies the nominal
electrical rating value given in the specication sheets, installation instructions and unit serial plate for the product
being used. To do so will provide the best unit performance possible from your new Bard product.
Single and Three Phase Power
Bard products are available in single and three phase power options. It is important to connect the proper phase
listed on the unit serial plate. Three phase power is often used to reduce energy usage, and units rated for 3 phase
operation are equipped with a phase monitor safety device. The phase monitor will not allow unit operation with
improper phase connection and a red LED light on the monitor indicates phase wiring issues. Connecting 3 phase
power to a single phase unit will result in component damage and improper unit operation. Connecting single phase
power to a 3 phase unit will also result in component damage and improper unit operation.
Hertz (Frequency)
Bard products are available in 50hz and 60hz power options. It is important to connect power with the proper hz
value listed on the unit serial plate. 60hz power is often used in the United States and Canada and units rated
for 50hz operation are normally for international sales outside of this area. Connecting 50hz power to a 60hz unit
not rated for 50hz operation may result in component damage and improper unit operation. Some equipment may
be rated for 50/60hz operation. Review the unit specications and installation instructions for further information
regarding the power requirements of the unit.
The product installation instructions and unit specication sheets contain additional information regarding unit
electrical data. This information may be accessed at www.bardhvac.com.

Manual 2100-034G
Page 12 of 21 Unit Maintenance –Filters
All Products – Filters and Filter Servicing
All Bard products contain air lters that must be cleaned or replaced on a regular basis.
Keeping air lter(s) clean is the single most important responsibility of the user of the equipment. Each type
of system must be equipped with an air lter(s) in the indoor circulating air system to clean the air, keep the
system itself clean for peak efciency and capacity and prolong the useful life of the equipment. DO NOT operate
the system without the proper air lters. Filters should be inspected at least monthly and replaced or cleaned
(depending on type) as needed. The useful life of an air lter can vary widely depending upon application and use
of the equipment, and it is critical to monitor lter condition and establish an acceptable maintenance schedule.
Failure to do so will increase operating and repair costs, decrease capacity and efciency and shorten the service
life of the equipment. A common symptom of a dirty lter in the cooling mode is a freeze-up of the indoor coil. The
air lters used may be a disposable (throwaway) type or may be a cleanable type that can be thoroughly cleaned,
rinsed and reused many times. It is important to make sure that the correct lter size and type for your system is
always used. If there is any question as to acceptable lter size or type, review the installation instructions for the
specic equipment involved, if available. Otherwise, consult with your installing dealer or service company. Most
equipment can have the lters inspected and serviced by the user with no problems. In some instances, because of
equipment design or specic installation conditions, it may be necessary to have this procedure done by a qualied
service company. Have your installer or service company show you where the lter(s) are and demonstrate the service
procedure or make arrangements for them to provide this service on an as-needed basis.
Outdoor Unit Wall Mount Room Air Filters
Wall mount lters are normally accessed from the outside of the building. Bard does offer a return air grille with a
lter frame built-in for indoor lter access. The return air lter grille is not acceptable as the only source of ltration
if vent options are installed in the wall mount unit.
The product installation instructions contain additional information regarding unit maintenance. This
information may be accessed at www.bardhvac.com.
Return Air Filter Grille:
Bard offers the RFG return air filter
grille, which may be used in applications
where outdoor air is not brought into the
structure through vent options. If vent
options are used, the filter tray inside the
Bard Wall Mount unit must be used.
Unit Maintenance

Manual 2100-034G
Page 13 of 21
Unit Maintenance –Filters
WALL MOUNT Products – Filters and Filter Servicing
The built-in lter tray and room air lters in the wall mount are located in the middle of the cabinet below the indoor
blowers. Units with vent options will have a washable screen behind the vent intake panel.
Filter Door:
The unit room air filter is located behind
this panel for units without a vent hood.
Vent Hood Door:
The unit indoor filter is located behind
this panel for units with a vent hood.
The hood contains a washable pre-filter
that needs to be cleaned regularly.
Vent Intake
Panel
Vent Intake Panel
Filter Door:
The unit room air filter is
located behind this panel.

Manual 2100-034G
Page 14 of 21 Unit Maintenance –Filters
I-TEC Indoor Products – Filters and Filter Servicing
The I-TEC indoor air conditioners and heat pumps have multiple lters that must be maintained and inspected when
servicing the unit. Filters play an important part in proper unit operation and prevent dirt and dust buildup inside the
I-TEC and the room the unit is installed in. To access the unit lters, open the front hinged doors by unlocking the
door latches. The doors fold outward and are on hinges with lift-off pins. Use care when opening doors. If doors are
lifted off of the hinge pins, use care as the dense insulation used for sound reduction causes the doors to be heavy.
The upper section of the unit contains two 2" x 24" x 30" throwaway lters as standard with every unit. MERV ratings
of the lter are available up to MERV13. These lters lter the air used for cooling inside the classroom or structure
and should be changed regularly.
If the unit has an air intake vent option installed, two 1" x 12" x 20" lters are located in the lower section of the
front doors behind the louvers. These lters help keep the vent option clean and operating properly.
Two washable lters are also installed in the air intake vent option. These should be inspected during servicing and
cleaned when necessary. The washable lters are used to remove dirt and dust from outdoor air that is entering the
vent area. If at any time these lters are damaged, they must be replaced with Bard-approved lters.
I-TEC Filter Locations:
Servicing the filters in your unit will help keep
the inside of the unit clean and also the area it is
installed in.
The I-TEC product installation instructions contain additional information regarding unit maintenance. This
information may be accessed at www.bardhvac.com.

Manual 2100-034G
Page 15 of 21
Unit Maintenance –Filters
Q-TEC Indoor Products – Filters and Filter Servicing
The Q-TEC indoor air conditioners and heat pumps have two room air lters that must be replaced when servicing
the unit. Filters play an important part in proper unit operation and prevent dirt and dust buildup inside the Q-TEC
and the room the unit is installed in. To access the unit lters, open the front hinged door by unlocking the door
latch. The door folds outward and is on hinges with lift-off pins. Use care when opening doors. If the door is lifted off
of the hinge pins, use care as the insulation and louver grille cause the door to be heavy.
The upper section of the Q-TEC contains two 1" throwaway lters standard with every unit. These lters lter the air
used for cooling inside the classroom or structure and should be changed regularly.
The Q-TEC product installation instructions contain additional information regarding unit maintenance. This
information may be accessed at www.bardhvac.com.
Q-TEC Filter Location:
The Q-TEC room air filters are
located behind this hinged door.
Unlock door latch and remove
screw to open door.
Screw location
Pre-filter location
The Q-TEC will have a permanent pre-lter installed inside
the wall sleeve if air intake vent options are inside the unit.
The pre-lter must be inspected and cleaned when necessary.
The easiest way to remove the pre-lter is through the outdoor
louver. Clean the pre-lter with soapy water.
QWS Unit QH/QA Unit
Filter locations

Manual 2100-034G
Page 16 of 21 Condenser Coil Cleaning
All Products – Coil Cleaning
The outdoor coil must be kept clean and free of any airborne debris, which can accumulate over time. Large
volumes of air are circulated over the coil, and airborne debris such as lint, dust, materials shed from trees, paper
or other types of airborne material that can become airborne can collect on the entering coil surface. The outdoor
coil must dissipate heat during the cooling mode and for a heat pump, also absorb heat during the heating mode.
If the coil is dirty and matted with debris, the airow across the coil will be reduced causing poor performance,
increased operating run time and associated utility bills and in extreme conditions can shorten the useful life of the
equipment.
Depending on the specic equipment involved, the surface that can accumulate debris can be on the opposite side
that is exposed to view when standing in front of the machine. Closely review the machine when operating to see
which direction or path the airow takes as it moves through the machine. If the air inlet side of the coil is hidden,
try to observe the back (hidden) side by looking into the side grilles, using a ashlight if necessary. While the user
of the equipment needs to be aware of the potential of clogging of the outdoor coil surface, actual cleaning of the
outdoor coil should not be attempted under most circumstances. If the user should attempt this procedure on their
own, never do so without rst having the installing dealer or service company instruct you in the proper procedure
and technique.
The product installation instructions contain additional information regarding unit coil cleaning.
This information may be accessed at www.bardhvac.com.
WARNING: Do not open or enter the equipment without rst turning off the electrical service disconnect.
Failure to do so can result in personal injury due to moving parts and/or electric shock hazard resulting in death.
Other conditions that can cause reduction of airow across the outdoor coil are owers, shrubbery or other growth too
near the outdoor coil air inlet and outlet openings. These living things, especially as they mature and grow, will be
just as effective in blocking the airow and create the same problems as will stacking things against the equipment.
These conditions can be easily managed and controlled by the user, as they do not require actually entering into the
equipment enclosure, which should only be done by qualied service technicians.
Equipment Corrosion Protection
1. Avoid having any lawn sprinkler spray directly on the equipment, especially if from a brackish water source.
2. In coastal areas or corrosive environments, locate equipment as far away from the corrosion source as feasible.
Units exposed directly to salt spray should be coated by a secondary protective coating operation to reduce
corrosion on copper tubing, fasteners, motors and other metal parts. Coils should be ordered with a corrosion
protective coating. Contact Bard for coating options.
3. Frequent cleaning and waxing of the cabinet using a good automobile polish will help extend its original
appearance and protect painted surfaces.

Manual 2100-034G
Page 17 of 21
Condenser Coil Cleaning
All Products – Condenser Airflow
W**A, W**H, T**H, T**S, W*RV Wall Mount Units:
These units are called “blow through condenser airflow” units
because they draw cool outdoor air from the sides and blow the
warm condenser air exiting the coil through the front grille.
C**H Wall Mount Units:
These units are called “draw through condenser airflow” units
because they draw cool outdoor air in the front through the coil and
blow the exiting warm condenser air through the unit sides.
I-TEC and Q-TEC Units:
These units draw the cool outdoor air through the top section of the wall
louver and exhaust the warmer condenser air out of the lower section of
the louver. I-TEC units also draw a small amount of air through the outer
right and left side of the louver.

Manual 2100-034G
Page 18 of 21 Unit Modes of Operation
Air-to-Air Cooling Products (Air Conditioners)
The cooling mode operates similar to a refrigerator, removing heat from inside the conditioned space and rejecting it
outside of the space being controlled. There are three main parts of the system:
1. The evaporator (indoor) coil where cold refrigerant absorbs heat from the air, which circulates from the
conditioned space through the machine and is returned to the space at a lower temperature and with some
of the humidity (moisture) removed. The moisture exits through a condensate drain system. A motor/blower
assembly moves the indoor air through the system.
2. The compressor, which is a sealed pump that moves the refrigerant through the system.
3. The condenser (outdoor) coil where the heat that was absorbed from the indoor space is discharged to the
outdoor environment. A motor/fan system moves the outdoor air across the condenser coil. A properly sized
air conditioner cannot cool a structure off rapidly and instead will pull down the temperature slowly. It also
will remove a certain amount of moisture (humidity) from the circulating airstream in the process. It may take
several hours to pull down a hot, moist building or structure on initial startup or anytime the system has been
turned off for a long period of time. It is generally best to set the thermostat at a comfortable temperature and
let it control the system as needed, rather than turning it on and off.
Moisture (humidity) removal with a conventional air conditioner (cooling) unit, or heat pump when operating in the
cooling mode, is not directly controlled and is a by-product of the unit operating to control temperature in response
to the temperature (thermostat) control device. Oversized equipment can easily control temperature but will have
short run-times, thus reducing its ability to remove moisture from the circulating air stream.
There are also many additional inuences that can affect humidity levels within the conditioned space such as
laundry appliances, cooking, showers, exhaust fans and any other items that can generate moisture or affect its
removal from the space. Therefore, while operation of the air conditioning or heat pump system in the cooling
mode will remove some amount of moisture as it reduces the air temperature, precise humidity regulation in the
conditioned space cannot be assured and additional equipment such as a dedicated dehumidier may be required.
Air-to-Air Cooling and Heating Products (Heat Pumps)
A heat pump is a refrigerant-based system that has additional components and controls that both heats and cools
using a compressor for both modes of operation. Most heat pumps will also be equipped with some amount of
electric heat to supplement the heating capacity of the compressor system on an as-needed basis. This operation is
entirely automatic and is controlled by the indoor thermostat and possibly also an outdoor thermostat.
Cooling Mode
The cooling mode of a heat pump is exactly the same as that described for an air conditioner in the above section.
Heating Mode
The system operates in reverse cycle, meaning that it absorbs and moves heat from the outdoors and transfers it
indoors to be rejected into the circulating air stream. Even though it seems cold to humans, there is usable heat
that can be extracted efciently from the outdoor air down to 0ºF, although the colder the air is there is less heat to
extract and the operating efciency is diminished.
Defrost Cycle
When operating in the heating mode, the outdoor coil will be colder than the outdoor air that is forced over it by the
fan system. When the outdoor air temperature is above approximately 40°F, moisture can accumulate on the coil
and it will drain down and out the base of the unit. As the air temperature gets below approximately 40°F, the coil
temperature will start to drop below 32°F, and frost or ice will begin to form on the coil.
An automatic defrost system keeps track of system run time when the outdoor coil temperature is in the freezing
zone and will initiate a defrost cycle at the appropriate time. The unit continues to operate during the defrost cycle,
but the outdoor fan motor will stop and the reversing valve will shift positions to ow hot refrigerant gas through the
outdoor coil to melt the accumulated frost. Water will start to drain freely from the unit, and steam may be emitted
from the unit.
The length of the defrost cycle will vary depending upon actual outdoor temperature, humidity levels and amount
of accumulated frost. It could range from 1-2 minutes up to but not exceeding 8 minutes. When the defrost cycle
Unit Operation