2.12 FLUE GAS VENT INSTALLATION
AERCO’s Benchmark Venting and Combustion Air Design Guide, TAG-0022 (GF-2050) must
be consulted before any flue or combustion air venting is designed or installed. Suitable, U/L
approved, positive pressure, watertight vent materials MUST be used for safety and UL
certification.
Once you have selected the vent material, enter that material in the Edge Controller:
1. Go to: Main Menu → Advanced Setup → Unit → Unit Settings.
2. Find the Vent Type parameter.
3. Set the value of this parameter to match your vent material: PVC, cPVC, Polypro or
Stainless Steel; the material sets the exhaust temperature limits. Note, PVC and cPVC are
allowed for BMK750 and 1000 ONLY, and only where governing codes allow.
Because the unit is capable of discharging low temperature exhaust gases, the flue must be
pitched back towards the unit a minimum of 1/4" per foot (0.64 cm per 0.3 m) to avoid any
condensate pooling and to allow for proper drainage.
While there is a positive flue pressure during operation, the combined pressure drop of vent and
combustion air systems must not exceed 140 equivalent feet (42.7m) or 0.8” W.C. (199 Pa).
Fittings as well as pipe lengths must be calculated as part of the equivalent length. For a natural
draft installation the draft must not exceed -0.25” W.C. (-62 Pa). These factors must be
planned into the vent installation. If the maximum allowable equivalent lengths of piping are
exceeded, the unit will not operate properly or reliably.
2.12.1 MASSACHUSETTS INSTALLATIONS
For Massachusetts installations, the following companies provide vent systems which conform to
all applicable requirements for installations within the Commonwealth of Massachusetts. Contact
information is as follows: