Rheem 97MDV060 Series Installation Instructions Manual page 26

GENERAL VENTING REQUIREMENTS AND
GUIDELINES
VENT PIPE SIZING AND MAXIMUM VENT LENGTHS (cont.)
TABLE 3: MAXIMUM EQUIVALENT VENT LENGTH
(-)97VA060M317USA
(-)97VA070M317USA
(-)97VA085M521USA
(-)97VA100M521USA
(-)97VA115M524USA
* This is the recommended maximum number of long sweep elbows for either 2 or 3 inch pipe. Combinations
of long sweep 90s, standard 90s, or 45s may be used, but the manufacturer recommends the use of long
sweep 90s whenever possible because the use of the maximum number of standard 90 and 45 elbows
only may result in nuisance furnace outages due to individual installation specifics.
Exceeding the recommended maximum number of elbows may cause nuisance operation of the pressure switch.
For modulating furnaces, non-direct venting is only authorized for
vertical terminations.
26
100