Specifications

• 10 • Application Guide • BALTIC - 0108
Transition Curb
According to the French regulation CH40 (Public buildings),
which says, that a gas rooftop with a burner bigger than 70 kW,
can not be installed directly on a roofcurb. Lennox has made
approved by the French minister of interior a special transition
curb including a free air ventilation of 20 cm high underneath
theRooftopoor,locatedbetweenthestandardroofcurband
the rooftop. This is a big time saver,because it allows again the
use of roofcurb on gas rooftop.
Horizontal / vertical Air Flow
Lennoxbelievesthatrooftopsshouldbeadaptabletospecic
designrequirements,thisiswhyavarietyofdownowreturn
and supply, horizontal supply and return or a mix of both are
offered.
Drive Kit up to 500 Pa (400Pa on size 20, 25, 30 and 35)
As all systems are different, it is useful to have the ability to
adapttodifferentairowconditionsandthiscanbeachieved
through the selection of various choices of motors and drives
thatcanprovideupto500Paatnominalairow.Thismeansthat
commissioning on site can be done easily and quickly, helping
youtokeepyourinstallationcoststoaminimum(*).
(*)
In order to minimize energy consumption and reliability, it is highly recom-
mended by LENNOX not to oversize the ESP (external static pressure) of the
Rooftop during the selection.
Air Sock Control
The use of air socks for space conditioning allows high air
volumes to be distributed at low velocity and is becoming a
common feature in many applications. To accommodate this
trend , Airsock control is offered which allows the air socks to
beprogressivelylled withaironstartup.BALTIChasbeen
enhanced with an electronic device to soft start the fan. It takes
1minutetogofrom0%ofairtofullairow.
FRESH AIR AND EXHAUST AIR
Economiser
"Free cooling" is provided through the use of fresh air where
appropriate rather than cooling the return air. The use of an
economiseristheeasiestandmostefcientwaytomodulate
fresh volumes and reduce running costs for a rooftop appli-
cation, as well as improving air quality. Fully controlled by the
CLIMATIC™ 50, it is also able to ensure that minimum fresh air
is provided in line with Indoor Air Quality Regulations. Economi-
ser operates using a "sensible" control. It is possible to prevent
the economiser from supplying air below a certain temperature
(adjustablesetpoint,10°Casdefault).
Theeconomiserisfactoryttedandtested,priortoshipmentand
includes 2 dampers operating from a 24V actuator. It includes a
rainhoodfactorytted.Hoodwillbefoldedduringtransportation
to limit risk of damage and is unfolded on site.
Gravity exhaust damper
Installed with economiser assembly, gravity exhaust damper re-
lief pressure when outside air is being introduced in the system. It
is a cheap and smart way to avoid overpressure in a building.
NOTE : When horizontal ow conguration is required, the
multidirectional roofcurb must be installed.
Power Exhaust Fan
Installed with economiser assembly, it provides exhaust air pres-
sure relief when high levels of outside air are being introduced
in the system.
Interlocked to run when return air dampers are being closed and
supply air blower is in operation. The extraction fan runs when
outdoorairdampersareatleast50%open(adjustable).Itisalso
overload protected. A gravity exhaust damper is supplied with this
option to prevent air from entering the unit during shutdown.
Return Roofcurb
Where system balancing is critical, it is recommended that an
exhaust fan is installed in the system. Instead of including the
exhaust fan inside the rooftop, LENNOX has designed a spe-
cial roofcurb that incorporates the return fan and handles the
exhaust function.
A centrifugal fan installed with a 3rd damper (1 inside the Roof
-
curb+2insidetherooftop),isabletoexhaustuptothenominal
airowoftheunit with a maximum of300Pastaticpressure
available. This roof curb can be used in either horizontal or
downowapplications.
FEATURES AND BENEFITS options and accessories