Exhaust vent material – U.S.A
PVC, CPVC, PPs, or SS venting materials are approved for use with these boilers in most of the
USA. Check local codes to determine if any materials are prohibited. The vent temperature is
limited with the use of the flue temperature sensor and software to ensure that the maximum
temperature of the PVC venting material is not exceeded. PVC venting material shall be certified
to Sch. 40 ASTM D1785 or D2665. CPVC material shall be certified to Sch. 40/ASTM F441.
Exhaust vent material - general
Use of cellular core PVC (ASTM F891), cellular core CPVC, or Radel® (polyphenolsulfone) in
venting systems is prohibited. Do not use ABS or any cellular core pipe for exhaust venting.
3.7.4 Direct vent
Direct vent is a two-pipe system that draws combustion air (air intake) from outdoors, and
discharges exhaust gases to the outdoors. Ensure that adequate separation is maintained
between the air intake inlet and the exhaust vent terminal. Refer to the vent terminal
configuration drawings in the "Vent Termination" sections.
Flue gas exhaust to outdoors
Combustion air from outdoors. "Direct Vent" installation: check air intake outside is
clear of obstructions.
Figure 15 Direct vent