Lennox FLEXAIR FAC Series User guide

lennoxemeia.com
FLEXAIR
FAC - FAG - FAH - FAM
APPLICATION
GUIDE
Air cooled rooftop packaged unit
85 230 kW
FLEXAIR-AGU-1505-E

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FLEXAIR
Application Guide /FLEXAIR-AGU-1505-E
APPLICATION GUIDE
Ref : FLEXAIR-AGU-1505-E
TABLE OF CONTENTS
All the technical and technological information contained in this manual, including any drawing and technical descriptions provided
by us, remain the property of Lennox and must not be utilised (except in operation of this product), reproduced, issued to or made
available to third parties without the prior written agreement of Lennox.
GENERAL DESCRIPTION
OPTIONS DESCRIPTION
GENERAL DATA
OPTIONS DATA
STANDARD UNIT PERFORMANCES
FAN PERFORMANCES
HEAT RECOVERY SOLUTIONS PERFORMANCES
HEATING AUXILIARIES PERFORMANCES
ACOUSTIC DATA
ELECTRICAL DATA
DIMENSIONAL DATA
OPTIONS WEIGHTS AND ACCESSORIES PRESSURE DROPS
Product designed and manufactured under quality management
systems certified ISO 9001 and ISO 14001.
Our company’s products comply
with European standards.

• 2 • Application Guide / FLEXAIR-AGU-1505-E

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FFLEXAIR
F A C 300 D N M 1 M
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C
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Application Guide /FLEXAIR-AGU-1505-E
MODEL NUMBER DESCRIPTION
EXAMPLE :
Cooling capacity in kW
Revision number
Air cooled
Water cooled
No condenser
1 Circuit
2 Circuits
3 Circuits
4 Circuits
Cooling
Heat pump
gas fired
dual fuel
heat recovery
High heat
Standard heat
No heat
R410A
HFO
No refrigerant
400V/3/50
230V/1/50

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EPBD
ENERGY PERFORMANCE OF
BUILDING DIRECTIVE
eComfort
™
efficiency senvironment
Application Guide / FLEXAIR-AGU-1505-E
1- GENERAL DESCRIPTION
Faced with challenges relating to competitiveness and climate
change, Europe has launched several initiatives for an intelligent
energy strategy.
New regulations reflect the European Union’s commitments on
climate change and its determination to reach 20% efficiency
improvement in buildings by 2020.
One of the major requirements of the new EPBD is to set Energy
Certificates for buildings which grade the energy efficiency based
on the building annual energy consumption. Soon companies
will have to display their energy certificates to the public.
THE EXPERIENCE & COMMITMENT OF
THE EUROPEAN LEADER TO DRIVE
CONTINUOUS ENERGY SAVINGS
Lennox contribution to combat rising energy costs and global
warming is to design innovative, efficient and dependable
products, while providing best comfort and air quality.
As a major player in the European
HVAC market, Lennox is a reference
in sustainable development and has
been assembling its products in ISO-
14001 certified factories since 2007.
eComfort illustrates Lennox
commitment towards energy
efficiency and environmentally
friendly solutions.
Like any other Lennox Rooftop
unit, FLEXAIR is Eurovent
certified.
SUSTAINABLE ENERGY
DEVELOPMENT CHALLENGES
FLEXAIR provides the best life cycle cost thanks to
high energy efficiency and reduced set up time and
maintenance costs.
Low Energy consumption
• For a packaged air conditioner, 90% of the CO2
emissions are indirect emissions caused by the
energy consumption.
• 35% energy savings with FLEXAIR when com-
pared to a standard rooftop installed on a retail
building.
• Innovative solutions for long lasting energy savings:
. eDrive Direct transmission variable speed ventilation system
. Advanced refrigeration system with multiscroll R410A com-
pressor assemblies, electronic expansion valves, extended
heat exchange surface area, alternate and dynamic defrost
cycles.
. Fresh air and free cooling management.
. Optimized operation with eClimatic
Reduced maintenance Costs
• Fully factory tested plug and play packaged system.
• eDRIVE direct transmission plug-fan with zero maintenance
and airflow measurement with eFlow.
• eClimatic, eClimatic Wizard, unit remote management and
supervision through GPRS with ADALINK Service.
Better recycling management
• Unit assembled in an ISO14001 certified facility.
• Refrigerant R410Ato reduce refrigerant charge.
• Reduced material usage with compact pac-
kaged design.
LENNOX : THE BEST LIFE CYCLE
COST IN THE MARKET

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Application Guide /FLEXAIR-AGU-1505-E
1- GENERAL DESCRIPTION
1.1. GENERAL FEATURES
FLEXAIR range constitutes a packaged solution, easy to deliver
and quick to install on the roof.
Operating range shall be between 46°C and minus 12°C with
4 versions : cooling, heating, cooling with gas burner or dual
heat (heating with gas burner). All units are factory assembled,
internally wired, fully charged with refrigerant, and 100% run-
tested before leaving the factory.
EC FANS TECHNOLOGY
FLEXAIR units are fitted with EC fans as standard, the variable
speed option will save energy and reduce maintenance costs.
HIGH INDOOR AIR QUALITY
Filtration
FLEXAIR offers different filtration levels, ensuring the minimum
pressure drop.
The unit is fitted with EU3 filters as standard, but it can be
configured with :
- G4 filters
- G4+F7 filter option / efficiency > 85% / 0,4 μm particles
Free cooling
Some times the thermodynamic cooling can be replaced by
free cooling by introducing cold outside air into the building.
FLEXAIR saves energy with automatic calibration of fresh air :
- Intelligent Fresh Air Management (patent 03 50616)
- Motorised fresh air damper with enthalpy control (option)
- CO2 sensor to adjust the percentage of fresh air to the Indoor
Air Quality (option)
eClimatic ADVANCED CONTROLLER
eClimatic is the new generation controller that improves efficiency
and helps set up and service operations to guarantees long
lasting performance
HEAT RECOVERY SOLUTIONS
FLEXAIR range includes a heat recovery wheel to recovery
energy from the extraction air
This heat recovery wheel is fitted in a separated module to be
installed on site
1.2. CASING
FLEXAIR indoor section is built with precoated galvanized steel
panels painted in RAL9003 color, specially designed for corrosion
resistance and to ensure long operation life time.
Double skin can be demanded as an option.
Condensing section mounted in a rigid base frame to ensure
good support for compressors and giving rigidity to the complete
structure.
1.3. ADVANCED REFRIGERANT
CIRCUIT
FLEXAIR presents the most advanced design in the refrigerant
pipes, optimizing pipe length and at the same time giving the
best access for service and maintenance operations.
The exchangers have been specially designed by Lennox for
R410Aoperation, this copper tube and aluminum fins exchangers
have been tested to give the best heat transfer and the best
energy ratios.
The refrigeration circuit is responsible for up to 40% of the annual
energy consumption of a typical packaged air conditioning unit.
FLEXAIR features high efficiency, environmentally friendly
refrigeration circuits with multiscroll R410A compressors,
electronic expansion valves and optimized heat exchange
surface area.

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SAVING ENERGY WITH ADVANCED
REFRIGERATION CIRCUIT DESIGN
R410A refrigerant
Efficient systems such as FLEXAIR are designed around R410A
refrigerant to achieve the best performances.
• Energy efficient refrigerant thanks with pressure drop in the
pipes: Higher evaporating pressure and lower condensing
pressure improve compressor EER & COP.
• R410A compressors have a better isentropic efficiency.
• Environmentally friendly refrigerant:
It contains No Chlorine (ODP =0). Significant refrigerant charge
reduction (-40%) that limits the global warming potential of the
system. R410A optimized heat exchangers use less material
(copper, aluminum …)
1- GENERAL DESCRIPTION
1.4. MULTISCROLL COMPRESSOR
TECHNOLOGY
FLEXAIR units are provided with tandem compressors, to profit
from the multiscroll compressor technology and giving the highest
seasonal performance and the best SEER coefficients.
High efficiency multiscroll technology
Air conditioning equipments are sized to cover the need for the
most critical weather conditions which most likely will occur only
a few days or even a few hours during the year.
Most of the time, in Europe, the external temperature drops below
the reference value and consequently systems usually run 96%
of the time at part load. It is therefore important to design system
around part load performance to achieve the lowest possible
annual energy consumption.
FLEXAIR provides high efficiency and best possible part load
efficiencies year round with high efficiency multiscroll R410A
compressor technology.
Evolution of the net EER with varying capacity load
Net EER
Capacity load in % of nominal
1,5
2,0
4,0
2,5
3,0
4,5
3,5
10 20 30 40 50 60 70 80 90 100
Inverter Scroll
Single Scroll
A
B
C
D
MultiScroll
MultiScroll + eDriveTM
AMultiscroll + eDRIVE CMultiscroll
BInverter scroll DSingle scroll
Source: PERSAPAC Study by Cetiat, Eurovent, Armine & EDF
Lennox Europe Laboratory comparative testing on rooftops

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Application Guide /FLEXAIR-AGU-1505-E
1.5. ELECTRONIC EXPANSION
VALVES
The new electronic expansion valves are directly driven by the
eClimatic and optimize the performances in both cooling and
heating mode and provide reliable and accurate operation in all
conditions all year round.
This model of electronic expansion valves ensures also smooth
and precise control at low capacities for improved part load
performances.
Multiscroll” compressor technology with electronic expansion
valves allows energy consumption reduction when compared
to “inverter” solutions:
• Multiscroll compressors are always running at their best
nominal operating conditions whereas compressors with
inverter control usually run at 90 Hz for nominal point down
to 30 Hz for low capacities.
• Energy consumption due to inverter electronics for speed
variation can reduce efficiency by up to 5%.
• Multiscroll compressor assemblies optimize heat exchanger
usage during part load operation. For example, with 50%
capacity load, a FLEXAIR would only start one compressor
on each circuit. The running compressors would then benefit
from the whole heat exchange surface area and the whole
airflow rate: The EER is then increased to 4.5 in some cases.
• Multiscroll compressor assemblies improve operating limits
giving the possibility to unload compressors providing cooling
to the building even when the outdoor temperatures are very
high. With unloading, FLEXAIR can operate and supply
cooling operating one compressor with outdoor temperatures
reaching 50°C.
1- GENERAL DESCRIPTION

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140 %
218 %
312 %
430 %
Application Guide / FLEXAIR-AGU-1505-E
Fan absorbed power with variable airflow rate
Fan absorbed power
(% of nominal)
Airflow rate
(% of nominal)
1.6- EC FANS IN SUPPLY AND EXTRACTION
Annual compressor consumption
Annual consumption of other electical systems
Remaining annual fan motor consumption
Energy savings thanks to eDRIVE
EC fan technology offers the maximum efficiency together with
the minimum power consumption. That’s why FLEXAIR provides
EC fans both in indoor and exhaust section.
FLEXAIR will adapt the fan pressure to the different conditions
of the unit, and will provide high pressure available in the duct
even when all the options have been selected.
The EC plug-fan technology allows:
- Adapting airflow at commissioning
- Varying airflow during unit operation providing progressive
inflation of smooth /textile ductworks
- Easy maintenance operations, as there is not pulleys and
belts regulation
eClimatic profits about this EC technology by:
-Monitoring the airflow in the service terminal
-Compensating the airflow if the filters are dirty
-Regulating the airflow to arrive to the desired set point tem-
perature.
Optimize the air-flow to the load demand (reduce consumption
when possible)
Condensing section mounted in a rigid base frame to ensure
good support for compressors and giving rigidity to the complete
structure.
eDRIVE
VENTILATION
eDRIVE is a standard feature
of Lennox FLEXAIR units
for ventilation with direct
transmission, variable speed
drives that saves energy and
reduces maintenance costs.
SAVING ENERGY WITH eDRIVE VARIABLE
SPEED, DIRECT DRIVE FAN.
With a rooftop, the blower fan motor is one of the major contributors
to annual energy consumption. Fans usually run 97% of the year
at full speed to circulate the air inside the building. 42% of the
annual energy consumption of an air conditioner is due to the
fan motor, which can be more than compressors.
VARIABLE SPEED DRIVE
Airflow reduction during part load operation and dead zone can
help save on energy consumption.
There is no need to reduce airflow rate too much to achieve
important energy savings: For example reducing airflow rate by
only 25% will save 60% on the fan motor energy usage.
• FLEXAIR integrates the new eDRIVE which automatically
adjust airflow rate to the needs, saving up to 30% annual
rooftop energy consumption.
• Airflow Rate can be easily adjusted to the exact needs, thanks
to eFlow the airflow measurement and display system.
• eDRIVE will correct power factor to reduce current.
• eDRIVE integrates soft starter feature as standard, that will
reduce inrush current during fan starts and makes the unit
fully compatible with flexible ducts air diffusion systems.
1- GENERAL DESCRIPTION