Mestek 44488010, Installation And Operation Instructions Manual

Page: 46 / 68

Form 43343350
Dec 2017
-45-
MULTIPLE HEATER VENTING (CONNECTIONS INTO A COMMON VENT OR MANIFOLD)
Requirements for venting of multiple heaters are the same as described for SINGLE HEATER VENTING except as
follows:
1.
The common vent size and total vent height is normally determined by the number of heaters per common
vent, length of horizontal connector runs, and connector fall. Connector lengths should be as short as
possible and have a minimum 1/4 inch per foot rise. Without regard to connector fall and total vent height
due to many possible venting configurations, the following should be observed:

Common vent pipe & vent connector diameter should be no less than that shown in the following Vent
Sizing Table.

A Y-connector must be used to the common vent.
2. Material for connectors and Y-connectors should be constructed of galvanized sheet metal or other approved
noncombustible corrosion resistant material as allowed by state or local codes. All common vent pipe
should be insulated flue pipe or double wall, Type B vent.
3. Avoid unnecessary bends. Limit to two (2) 90º elbows.
4. The entire length of vent connector shall be readily accessible for inspection, cleaning and replacement.
5. Groups of heaters with a common vent must be controlled by a common thermostat.
If any heater connected to a common vent system for multiple
heaters is found inoperative, the heater should be disconnected from
the vent system and its entrance into the vent system capped.