Specifications

12/03/2013 Page 21 of 40
GF-2050
Benchmark Series Boilers
Venting and Combustion Application Guide
TAG-0022_0S
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526-0288
manifold to a floor drain. Condensate manifolds must be large enough to handle the anticipated
flow and must be properly secured and protected. Manifolds are generally located behind the
boilers so that short runs of plastic tubing into the manifold can be used for the condensate
drain. A base drain must be installed at the bottom of vertical common flue piping.
The pH level of the condensate produced by Benchmark boilers ranges between 3.0 and 3.2.
The installation should be designed in accordance with local codes that specify acceptable pH
limits. If required, any type of commercially available neutralizer may be used.
1.21 Individually Vented Systems
Systems with individual vents may be used with any of the combustion air systems described
previously and illustrated in Figures 9a and 9b. The maximum combined pressure drop of the
vent and combustion air system must not exceed 140 equivalent feet of length.
To calculate the pressure drop:
1) Calculate the exhaust vent pressure drop.
2) Calculate the combustion duct pressure drop.
3) Divide the vent pressure drop by the altitude correction factor (CF) listed in Table 4 to
correct for installations above sea level.
4) Determine the natural draft, if any, from Table 3 and multiply it by the altitude CF.
5) Add the altitude corrected vent pressure drop (positive) and the draft (negative) to get
the total vent pressure drop.
6) Add the total vent pressure drop to the altitude corrected combustion air duct pressure
drop.
The total system pressure drop must not exceed 140 equivalent feet.