Vermont castings ewf36a, Installating outside air kit, Installation precautions – Vermont Casting EWF36 User Manual
Page 11: Installation instructions

11
Vermont Castings EWF36A
20005167
Installating Outside Air Kit
An outside air kit may be installed on the EWF36A. If 
desired, or if local codes mandate the use of an air kit, 
then two (2) AK-MSTs are required to complete the 
installation (from air kit to the outdoors). If the outside 
air kits are to be used, the AK-MSTs MUST be installed 
BEFORE the fireplace is enclosed.
NOTE: Air duct assemblies must be installed in con-
junction with the AK-MST or cold air will enter the home. 
(Fig. 14)
NOTE: Four (4) inch Class 1 air duct, material or metal 
duct (not supplied) may be used with AK-MST. (For 
installation in New York State, only aluminum, non-
combustible flexible or type “O” metal ducting is 
permissible.)
Installation Precautions
The duct termination should be located so it is exposed 
to an out-of-doors opening at least 100 square inches. If 
the duct termination must be located in a crawl space or 
basement, be sure the termination area has 100 square 
inches of ventilation opening to outside air.
The duct termination must be located so it does not 
compete for air flow with exhaust fans, gas vent hoods 
or other air consuming devices or appliances. It must 
not be obstructed by rafters, insulation materials or 
other obstructions. The less restrictive the air supply, 
the better the AK-MST will perform.
It is a good practice to protect your hands and eyes 
during installation by wearing work gloves and safety 
glasses.
CAUTION: Do not install termination into a garage 
or other area that could contain flammable liquids 
or fumes, or into an attic space.
Installation Instructions
Determine the location of the fireplace as described 
in the fireplace Installation Manual. Then plan location 
of the duct termination and the route of the duct run 
between the fireplace and the duct termination.
Duct run must be limited to a maximum distance of 40 
feet from the fireplace pipe collar to duct termination. 
This will provide the least restriction to air flow. No more 
than four (4) 90° elbows can be used. Duct run may 
be horizontal, vertical, inclined or any combination of 
these. Vertical duct runs must be at least three (3) feet 
below the fireplace chimney flue exit. (Fig. 13) You are 
now ready to install the AK-MST Outside Air Kit.
FP1060
AKMST installation
7/6/00 djt
Duct Termination
Must be More Than 3’
Below Chimney
40’ Max.
Duct Run
Duct Termi-
nation
Ceiling
Attic
Duct
Soffit Termination
Exterior Wall
Rain Cap
Duct Termina-
tion
40’ Max. Duct Run
Duct
Exterior Wall Termination
FP1060
Fig. 13 Typical installations.
Fig. 12 Fasten fireplace in position.
Nail Top Stand-
offs
Nail Side
Nailing
Flanges
FP1197
FP1197
EPA36
nailing flanges
3/20/02 djt
1. Remove and discard the outside air cover plate
located at the center of both sides of the fireplace. 
Use care not to rub against the sharp edges of this 
opening to avoid cuts. Remove the four (4) screws 
