Brochure

7
Draft Control
Fig. 1
Fig. 2
(Installation Options)
Recommended Locations for Field Draft Controls
For gas-fired equipment, the preferred location of the
control is on the bull head tee. This location provides
maximum relief of downdrafts with minimum positive
pressure. (See Fig. 1, Dia. A-C)
With oil or solid fuels, the bull head tee is not
recommended, so locate the control as shown.
(See Fig. 1, Dia. D-J) These locations are acceptable
for gas units as well. Except on forced draft systems,
locate the control as close as possible to the furnace or
boiler, at least 12" beyond a stack switch on oil-fired
units, and at least 18" from a combustible ceiling
or wall.
Commercial and industrial furnaces and boilers are
frequently installed in multiples. (See Fig. 2)
Use a draft control for each boiler located on the
uptake between the smoke outlet and the breaching
(location A). When this uptake is too short to permit
the installation of a control, locate a separate control
for each boiler on the main breaching (location B). If
neither of these locations is possible, use a single large
control in the breaching between the chimney and the
nearest boiler (location C).
Where several units are vented into a common
breaching, the most draft-critical should vent highest
in, or be placed closest to the chimney. Incinerators
should generally be placed farthest from, or vented
lowest in the chimney.
Multiple Appliance Location Recommendations