Snout on a F-9A or F-9AX
Each JUCA F-9A or F-9AX unit has its firebox surrounded by a number of heat exchanger chambers on all sides. This means that the overall width and height of a JUCA unit is somewhat larger than the (visible) brass door assembly, which is the only part of the F-9A or F-9AX that is seen once it is fully installed.
As long as enough room exists for the larger body of our unit and the safety clearances necessary around it, there is generally little problem in this. The only possible installation problem would be in closing the unit in with the facing materials once installation is complete. If the brass door assembly had been just attached onto the front of the body of the JUCA unit, then there would have been a metal area surrounding the brass door assembly that would have remained visible from the room.
To avoid this appearance gaffe, JUCA sets the main body of the F-9A and F-9AX units back (usually about 4") from the final surface of the room wall, and includes a "snout" extension to connect the main body's firebox with the door assembly. This snout is generally slightly smaller in width and height than the overall width and height of the brass door set that will eventually attach to the front edge of it. This allows at least two possible choices about the final installed appearance of the JUCA F-9A or F-9AX.
Overlap MountThis is the normal way most fireplace doors are installed. The BACK surface of the brass door set is at the finished surface of the room wall. The fireplace facing materials are usually fairly flat, like with facebrick or ceramic tile or marble or veneer brick, and those materials are installed right up to or very near the outer sides of the snout. With a standard width F-9A, with a snout that is about 32" wide, this means that the facing materials cover everything EXCEPT for a space of about 32 or 32 1/2" wide where the snout comes through. In most installations, it is not critical for the facing materials to actually abut the outside surfaces of the snout. Since the brass door assembly is WIDER than the snout (many of the standard width door assemblies range from 34" to 36" inches wide), it OVERLAPS an inch or two of the facing brick surface, on both sides and above. The OVERLAP mount way thus means that the THICKNESS of the brass door set (often about 1 1/4") extends out into the room. This is by far the most common way brass door sets are installed on fireplaces.
Let's say that you have very rough surface fieldstone as the facing of the fireplace. A door set that would overlap such material would have gaps behind it in that overlap area, that would need to be filled in with caulking or mortar, in order to properly separate the firebox chamber from the air in the room. In such a case, a recessed appearance might be best. Let's say that you have decided that you want the front surface of the brass door assembly to be recessed 1/2", and the specific brass door set you selected is 1 1/4" thick. In this case, you would just initially place the JUCA so that the FRONT EDGE of the JUCA snout is set back 1 3/4" from where the final room wall surface will eventually be. The only other significant difference in installation is involved in installing the facing materials. In this case, instead of putting facing materials right up to or near the snout, it is necessary to leave an opening in the facing materials approximately 1/4" wider and 1/8" higher than the OUTSIDE dimensions of the specific brass door assembly you selected. Often, this means that there might be a narrow gap between the snout and the facing materials. If this is the case, it is especially important to surround the JUCA's blower with a cold air return box and duct, and NOT let the blower use the entire fireplace chase as its cold air return. This is because the blower would cause a low pressure area in such a chase, and if such a gap was present around the snout, and if a little bit of air could fit between the brass door set and the front edge of the snout, the blower might be able to suck smoky air out of the firebox via this path. So DON'T!
After all the masonry work is completed, the brass door set would be installed, and then high temperature silicone-based caulking used around the perimeter of the brass door set, to seal it to the facing materials.
In the same way as with the sides, the lintel could be bridged across with a narrow gap underneath it, especially with overlap fit installations. For Arch-Top fireplace doors, there are special arch-top lintels made to support the weight of the masonry above it.
If you use veneer brick, stone, slate, tile, marble, etc, that material will be attached to a backing panel of cement board. This type of installation USUALLY leaves a empty space behind the cement board. This is fine! There is absolutely NO reason to try to fill that space in with anything.
Continuing along this line, the physical position of the JUCA can be moved forward or back so the outer edge of the snout is at whatever location you desire. As mentioned above, for a recessed door set, slide it back a little. For an overlap mount, it can be at or near the final surface of the fireplace facing.
There is actually no absolute reason that the snout even has to come all the way out to the door assembly. Sometimes, people know before they place an order that they will use 8" diameter river or field stones to face their fireplace, so we could put an 8" snout on the unit. If, however, this possibility only arises after the unit has arrived, no problem! Just move the body of the JUCA four inches farther back. The stones will extend out four inches past the JUCA snout. The lintel up above also does. The door set could then be mounted to the stonework, four inches away from the snout. Or it could be mounted partially recessed into the opening, so it is just one or two inches from the snout. A lot of flexibility!
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