Specifications
23
Example: A two-sided replace measures 24” x 36”
on the largest size. The opening measures 864 sq.in.
Multiply by 2 and the opening used for the selection
table is 1,728 sq.in.
For this method a chimney or ue opening must
be expressed as the inside diameter in inches. For
a round chimney or ue this is not a problem as
the size is expressed as 9”ID, indicating the inside
diameter is 9”.
Oval, square or rectangular chimney must rst be
converted to an equivalent ID. If the ue is a clay tile,
then the table below shows the typical standard ue
tile size along with the equivalent ID:
Example: A replace is served by a ue that is 8” x
12” or 9 in ID.
Flue sizes not shown in above table can be
converted using the table in Appendix B.
Check that there are no more than 2x90° elbows and
no more than 30’ of height. If there are more than
2x90° elbows, use a bigger fan or contact ENERVEX
for a custom sizing.
The following table is used for replaces that are
wood red:
Outside
Dimensions (inch)
Effective Flue
Area (sq.in.)
Equivalent
Diameter (ID) (inch)
4 1/2 x 8 1/2 23 5
4 1/2 x 13 34 6
8 x 8 42 7
8 1/2 x 8 1/2 49 8
8 x 12 67 9
8 1/2 x 13 76 10
8 1/2 x 18 102 11
12 x 12 102 11
12 x 16 131 13
13 x 13 127 12
13 x 18 173 14
16 x 16 181 15
16 x 20 222 16
18 x 18 233 17
20 x 20 298 19
20 x 24 335 20
24 x 24 431 23
Step 2 - Determine the size of the chimney opening
Note: The black background indicates that the fan will most likely
create some air-ow noise due to a high air velocity in the chimney.
The light grey background indicates the fan base will not cover the
chimney opening and a special adapter must be used.
Example: We have calculated a 24” x 36” (864 sq.in.)
wood-red replace and a chimney ue at 8” x 12”
or 9 in ID. Using the table we need to use a model
RSHT12.
If the application involves a gas-red appliance use
this table:
Eff.
Flue
ID
Fireplace Opening (sq.in.) - Gas
400 600 1,000 2,000 2,500 3,000 3,500 5,000
5 RS99 RS12 - - - - - -
6 RS9 RS9 RS14 - - - - -
7 RS9 RS9 RS12 - - - - -
8 RS9 RS9 RS9 RS16 - - - -
9 RS9 RS9 RS9 RS14 RS16 - - -
10 RS9 RS9 RS9 RS12 RS14 RS16 - -
12 RS9 RS9 RS9 RS12 RS14 RS14 RS16 -
14 RS9 RS9 RS9 RS12 RS14 RS14 RS14 -
16 RS9 RS9 RS9 RS12 RS14 RS14 RS14 RS16
18 RS9 RS9 RS9 RS12 RS14 RS14 RS14 RS16
20 RS9 RS9 RS9 RS12 RS14 RS14 RS14 RS16
22 RS9 RS9 RS9 RS12 RS14 RS14 RS14 RS16
24 RS9 RS9 RS12 RS14 RS14 RS14 RS16
Note: The black background indicates that the fan will most likely
create some air-ow noise due to a high air velocity in the chimney.
The light grey background indicates the fan base will not cover the
chimney opening and a special adapter must be used.
Examples: We have calculated a 24” x 36” (864
sq.in.) gas-red replace and a chimney ue at
8” x 12” or 9 in ID. Using the table we need to use
a model RS 9 - one size smaller than the above
sample using a wood-red replace.
Step 3 - Check number of offsets and height
Step 4 - Select a fan from the sizing table
Eff.
Flue
ID
Fireplace Opening (sq.in.) - Wood
400 600 900 1,200 1,500 2,000
2,500
5 RSHT12 - - - - -
-
6 RSHT9 RSHT12 - - - -
-
7 RSHT9 RSHT12 RSHT12 - - -
-
8 RSHT9 RSHT12 RSHT12 RSHT14 RSHT14 -
-
9 RSHT9 RSHT12 RSHT12 RSHT14 RSHT14 -
-
10 RSHT9 RSHT12 RSHT12 RSHT14 RSHT14 RSHT16
-
12 RSHT9 RSHT12 RSHT12 RSHT14 RSHT14 RSHT16
RSHT16
14 RSHT9 RSHT12 RSHT12 RSHT14 RSHT14 RSHT16
RSHT16
16 RSHT9 RSHT12 RSHT12 RSHT14 RSHT14 RSHT16
RSHT16
18 RSHT9 RSHT12 RSHT12 RSHT14 RSHT14 RSHT16
RSHT16
20 RSHT9 RSHT12 RSHT12 RSHT14 RSHT14 RSHT16
RSHT16
22 RSHT9 RSHT12 RSHT12 RSHT14 RSHT14 RSHT16 RSHT16
24 RSHT9 RSHT12 RSHT12 RSHT14 RSHT14 RSHT16 RSHT16