Chimney Fan Source - Enervex Exhausto Chimney Fan Selection Chimney Fan Sizing And Selection.

The World's Finest Mechanical Draft Systems

Enervex Chimney Fans
Model RS Chimney Fan Selection
Wood and Gas Fired Fireplaces and Stoves

QUICK SIZING.... STEP 1 Determine the type of opening, measure and calculate.....


One-sided	Two-sided (See-through)	Corner	Three-sided	Free-standing	Free-standing Round
A x B	1.5 x A x B	A x B	( A + B ) x C	1.5 x A x B	1.185 x A²

QUICK SIZING.... STEP 2

Determine the type of flue and measure the INSIDE measurement... use the chart below to convert square and rectangular to round.

CONVERSION OF Rectangular / Square to Round Flues

Measure the INSIDE ( side to side ) measurements of the clay liner.

Ex... The INSIDE measurement of 6 x 10" on a clay liner is equivalent to

10 (dim. A) - 6 (dim. B) = 8 (8" Round)

NOTE: Clay liners are "called" by their OUTSIDE measurements, the INSIDE measurements may vary depending on the manufacturer and location.
EX. A 13x13 clay liner may only have an INSIDE measurement of 10" x 10"

QUICK SIZING.... STEP 3

Use of the following fan selection tables below to calculate the Enervex fan required to fully exhaust the fireplace opening and flue system.

Note: The RED background indicates that the fan will most likely create some air-flow noise due to a high air velocity in the chimney.
The BLUE background indicates the fan base will not cover the chimney opening and a special adapter must be used.

	Fireplaces (wood-fired)
	Fireplace Opening in square inches
Flue Size	Max. 400	Max. 600	Max. 900	Max. 1200	Max. 1500	Max. 2000	Max. 2500	Max. 3300
5	RS 12	RS 16	*	*	*	*	*	*
6	RS 9	RS 12	RS 16	*	*	*	*	*
7	RS 9	RS 9	RS 14	RS 16	*	*	*	*
8	RS 9	RS 9	RS 12	RS 14	RS 16	*	*	*
9	RS 9	RS 9	RS 12	RS 14	RS 16	RS 16	*	*
10	RS 9	RS 9	RS 12	RS 12	RS 14	RS 16	*	*
12	RS 9	RS 9	RS 12	RS 12	RS 14	RS 14	RS 16	*
14	RS 9	RS 9	RS 12	RS 12	RS 12	RS 12	RS 14	RS 16
16	RS 9	RS 9	RS 12	RS 12	RS 12	RS 12	RS 14	RS 16
18	RS 9	RS 9	RS 12	RS 12	RS 12	RS 12	RS 14	RS 16
20	RS 9	RS 9	RS 12	RS 12	RS 12	RS 12	RS 14	RS 16
22	RS 9	RS 9	RS 12	RS 12	RS 12	RS 12	RS 14	RS 16
24	RS 9	RS 9	RS 12	RS 12	RS 12	RS 12	RS 14	RS 16

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.

The "opening in square inches" refers to the fireplace or appliances over-all face opening.

Example : In a small wood burning fireplace, if the hearth opening is 18" x 24" with an 8" round ( INSIDE MEASUREMENT ) clay liner in a brick and mortar chimney we would...

Multiply the length and width, in this case 18" x 24" = 432 square inches. Being less than 600, on the wood burning chart above, follow the column to the 8" flue size. Highlighted in orange, the chart shows an RS 9 to be the proper size chimney fan for this application.

	Fireplaces (gas-fired)
	Fireplace Opening in square inches
Flue Size	Max. 400	Max. 600	Max. 1000	Max. 2000	Max. 2500	Max. 3000	Max. 3500	Max. 5000
5	RS 9	RS 12	*	*	*	*	*	*
6	RS 9	RS 9	RS 12	*	*	*	*	*
7	RS 9	RS 9	RS 12	RS 14	RS 14	*	*	*
8	RS 9	RS 9	RS 9	RS 12	RS 16	*	*	*
9	RS 9	RS 9	RS 9	RS 12	RS 12	*	*	*
10	RS 9	RS 9	RS 9	RS 12	RS 14	RS 16	RS 16	*
12	RS 9	RS 9	RS 9	RS 12	RS 14	RS 14	RS 16	*
14	RS 9	RS 9	RS 9	RS 12	RS 14	RS 14	RS 14	*
16	RS 9	RS 9	RS 9	RS 12	RS 14	RS 14	RS 14	*
18	RS 9	RS 9	RS 9	RS 12	RS 14	RS 14	RS 14	RS 16
20	RS 9	RS 9	RS 9	RS 12	RS 14	RS 14	RS 14	RS 16
22	RS 9	RS 9	RS 9	RS 12	RS 14	RS 14	RS 14	RS 16
24	RS 9	RS 9	RS 9	RS 12	RS 14	RS 14	RS 14	RS 16

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.

Gas fireplaces will need additional controls...

PDS (Proven Draft Switch) Safety control that senses a draft. A pressure sensor that ties into the log set or appliance controls and would shut the gas off if the draft became negative.

ADC 100 A pre/post purge control that would extend the the fan cycle before and after gas is present for a fireplace or appliance.

NEW!!! MFD Mechanical Fireplace Damper. Prevents excess heat from escaping through the chimney when the fireplace is not in use.

Wood stoves, coal stoves and fireplace inserts

	Stoves	Fireplace Inserts
	Door Opening in square inches A x B
Flue Size	Max. 300	OVER 300
6	RS 9	RS 12
7	RS 9	RS 12
8	RS 9	RS 12
9	RS 9	RS 12
10	RS 9	RS 12

Check that there are no more than 2x90° elbows and no more than 30’ of height.
If there is more than 2x90° elbows, use a bigger fan.

Fan Specifications

1 Junction Box
2 Conduit/cord
3 Motor
4 Motor Housing
5 Cooling Plates
6 Bird Screen
7 Base Plate
8 Locking Nut
9 Inlet
10 Axial Vane
11 Hinges
12 Capacitor
( inside J-box )

Capacitor
Wiring Diagram