13
IV: VENTING (NATURAL VENT - CHIMNEY)
J.
INSTALL BREECHING.
For normal installation in
a large confined space refer to local codes for proper
selection of the breeching materials.
For installation in a confined space such as an under-
counter installation, special consideration must be given
to the selection of breeching material. The temperature
within the confined space will be higher than in the normal
installation. One major source of those higher temperature
is the exposed breeching within the confined space. Thus,
it is required that any exposed breeching be constructed
of type "L" are equivalent vent material.
Furthermore, the likelihood of accidental ignition of
combustibles within 12" of the breeching is increased
when the boiler is installed in a confined space. This is
due to the lack of free air movement over the surfaces
to cool them. For this reason THE ENTIRE LENGTH
OF BREECHING FROM THE OUTLET OF THE
BOILER TO THE CHIMNEY MUST BE INSTALLED
ACCORDING TO NFPA 211, OR LOCAL CODES. Refer
to Figures 11, 12 and 13.
Figure 11: Installation of FO in a Confined Space with Adjacent Chimney
NOTE:
1. Type L Vent Material generally means stainless steel inner liner and stainless steel outer covering and separated with 1"
thick special high temperature insulation - factory assembled and rated.
2. In a confined space, provide ventilation air to the burner and size such ventilation air openings to provide not less than 28
square inches free area per gallon of fuel input to the burner.
3. Keep right side of boiler accessible for flue cleanout and tankless coil maintenance.
4. Boiler is heavily insulated and is suitable for 1" clearance from jacket surface to combustibles.
5. Boiler is of wet base design and suitable for installation on combustible floors.
6. The original installation may have been under poor or outdated building codes. Replacement boilers are subject to codes
in effect at the time of replacement. Be sure to consult with local code officials before starting replacement.
