Skutt EnviroVent - Manual (Page 9)

9
Additional ventilation may be necessary when firing with wax resist; using high sulphur or
organic content clay bodies and glazes, thick-walled (over 1/4” thick) bisque pieces; firing
outside the United States where 50 cycle electricity is supplied; or when additional volume
is added to the kiln with a blank or wired ring.
If it is necessary to increase ventilation, drill additional hole(s) in the kiln floor only. For an
eight-sided kiln, drill one additional small (#21) hole. For a ten-sided kiln, drill two
additional small (#21) holes. For a twelve-sided kiln, drill one additional large (15/64”)
hole. Do not drill more than 6 large holes in the bottom of a kiln.
Insufficient ventilation can cause black or gray interiors in bisque, reduce element life, and
permanently alter some colors. However, too much ventilation may decrease the heating
uniformity of the kiln, so reducing the load may be the best solution.
Fume Removal
The EnviroVent

pulls air into the kiln near or at the top, then draws air out of the kiln near
or at the bottom during firing. This method causes the air pressure in the kiln to be slightly
lower than outside of the kiln. As a result of this negative pressure, air will be pulled into
the kiln through any hole or crack. This will remove essentially 100% of the fumes
generated, providing:
1 the system is installed properly for controlled air flow
2. the kiln is not excessively loaded with ware
3. heating rates are less than 150

C/hour or 300

F/hour for heavy loads
4. the kiln does not contain gaps, holes or large cracks
The 4” exhaust venting from the kiln to the outside is positive pressure. Take care to ensure
all joints are sealed (duct tape or high temperature silicone sealant work well) to prevent
fumes from entering the room.