Ed. 11/2006
User, Installation and Service Manual for F1 Gas Unit Heaters
10
Figure 4
POSITION OF THE UNITS
SIZE AND INSTALLATION OF THE AIR INLET / FLUE EXHAUST
F1 Series gas fired unit heaters can be installed as following:
-
B
23
type installation, combustion air taken directly from the room and flue exhaust gases to the
outside. This exhaust flue duct can be either horizontal or vertical. This type of installation is not
sealed regarding the heated room (see figures 6/7).
-
C
13
e C
33
type installation; room sealed combustion circuit. Appliance with inlet air supply and
outlet of exhaust gases with, either, concentric or separate ducts - horizontal (for
C
13
see figures
8/9) or vertical ones (for
C
33
see figure 10).
-
C
53
type installation: room sealed combustion circuit; appliance with inlet air supply and outlet of
exhaust gases by using separated ducts and terminals n different walls, for example, the air inlet duct
from the wall behind the appliance and the flue exhaust duct on the roof (see figure 11).
-
C
63
type installation: allows installing the certified air inlet/flue exhaust ducts, elbows and
terminals purchased on the market. Moreover, it permits to use the pipe diameters bigger than
80mm: for example when the installation requires using the pipe of the larger diameter, caused
by the longer ducts. With this typology, for the calculus of the flue/air inlet duct refer to the duct
manufacturers data and furthermore to the flue composition, flue flow and its temperature. (see
table 2).
Use only approved ducts for the installation of the units. Upon request, manufacturer can supply
approved rigid pipes, coaxial pipes and terminals.
To determine a correct size of the flue system its total pressure drop has to be calculated.
The allowed pressure drop in the pipe system depends on the model of the unit (see table 2).
Table 3 shows the maximum allowed pressure drop for each unit - diameters Ø80 and Ø100; it
shows the losses of the exhaust and air intake flues regarding the coaxial ducts supplied by
manufacturer.
External terminals pressure losses are negligible since it is very low.
Check the total inlet/outlet pipes pressure losses regarding maximum values given by table 2. On
the next page follows the example of pressure loss calculation and respective duct project. It must
be checked that the total amount of the flue system pressure losses are within the minimum and
the maximum losses allowed for the unit (see table 2).
Table 4 gives the lengths of the air supply and flue exhaust ducts for different types of installation.
These values are APPROXIMATE for the types of installation shown on the figures 6,7,8,9,10 and
11.
