Insert in custom masonry alcove?

[freeman.public]

I have an Osburn 2200 insert in a fireplace and love it. I am building a new fireplace in a family room for a second unit. What I would love to do is instead of building a full fireplace, and putting a liner in the flue, is to build a fireplace sized box out of masonry (firebrick + regular brick for an 8" wall) and put an 8" reinforced concrete cap on this (30" off of the masonry floor). I would put an HT wood stove chimney in the back, with the thimble throught the back wall.

The benefits are:
1. With an HT chimney out the back (into my garage), I can clean the chimney from the bottom (using the "T").
2. I get a better venting system for this unit
3. I can more easily make a recessed box in the wall above this (out of brick) for a plasma television.

Now, if I was placing a wood stove in this alcove, I would have no concerns, as there are no combustables anywhere near the unit; however, with the insert, the "clearances to combustables" are not given. Rationally, I am confident they are the same, but the instructions say that the unit must be installed in a fireplace. The walls of the masonry box are identical to a fireplace, only the cap is different. I would probably place fiberglass bats on top of the concrete cap.

Are my ideas reasonable? or should I go ahead and build the full masonry fireplace (I have not found one that is big enough to hold the insert AND is rated for an insert.

If I build a full fireplace, any thoughts on whether it is reasonable to build a recessed cavity (say 8" deep or so) right above it for a plasma screen? My thoughts are that the recess will help with the heat.

 

[thechimneysweep]

Your masonry alcove idea wouldn't fly in any of the four code jurisdictions our service dept. works in: all require a code-approved fireplace to put an insert into. You could install a free-standing unit in an enclosure such as you describe, though.

Plasma TV's create a lot of heat, so they have their own built-in air cooling systems which draw air in through slots at the bottom of the rear housing and out similar slots at the top. According to my local electronics guru, intake air temperatures must be kept below 90 degrees F, or premature death of the plaz is likely. The heated air that flows out the top openings in wood inserts is much hotter than 90 degrees, so he says don't do it.

 

[elkimmeg]

Clean outs are not allowed in garage locations 10 " of solid masonry is required using fire brick lined fire boxes 12" without fire bricks
If a true fire place with smoke shelf and throat the size your o fireplace opening will require at least a 12/12 masonry clay flue which will have to be lined with a approved liner for the insert Per cross-sectional code. Having an insert below a plasma TV the bricls and masonry will store heat it will cook the tv. If that were not enough the heat radiating from the stove also would finish the tv the tv also would have to be 36" above the top of the insert again another code issue. You could avoid many of the issues by building a masonry front and 8/8 clay flue line and instasll a free standing stove again the stoves' heat would cook the plasma tv

 

[mlouwho]

What you are suggesting would not be approved anywhere around here. Why not install a zero clearance high efficient wood fireplace. For example RSF Opel or Delta, Regency Warm Hearth, Security BIS. Each of these is going to work just like a quality woodstove or insert, but is designed to be installed the way you want to use it. And you would get a larger viewing window at probably less cost than you are looking at your way. All of these require a class A stainless steel chimney, I would recommend going straight up through your alcove.

 

[wg_bent]

Go over to the Perfect Picture forum and look at DonCT's "So it begins" thread. It's a corner alcove of sorts...(nicely done I might add). Is that what your thinking? I agree with all the previous posts. An insert in an alcove?? It's funny, since I had the same thought at one time. You should also look at the Napoleon High country, and I thought Avalon also had one, but I can't find it on their website.

 

[elkimmeg]

What you are suggesting would not be approved anywhere around here. Why not install a zero clearance high efficient wood fireplace. For example RSF Opel or Delta, Regency Warm Hearth, Security BIS. Each of these is going to work just like a quality woodstove or insert, but is designed to be installed the way you want to use it. And you would get a larger viewing window at probably less cost than you are looking at your way. All of these require a class A stainless steel chimney, I would recommend going straight up through your alcove.

I like and agree with mlouwho suggestions. I also believe Qudra -fire 7000fp is such a brand Majestic also make a few models that fit the bill. I think your tv location is ill advised. Looks great in pictures, but not situated, that it life's expectancy bodes well

this is being discussed in the post a few down from yours quadra fire 7000fp

 

[Shane]

I've never seen a plasma tv put above a wood burner, but 4 years ago I installed 3 FPX44DVXXL gas fireplaces and 2 of those have 47" plasmas above them and they've worked beautifully for 4 years and counting.

 

[mlouwho]

Elk, I hate to contradict your opinion since this is the first time you have liked one of my suggestions, but I have done many plasma TV's above wood burning Fireplaces, even heat producing ones like mentioned above. As long as you have a 8 - 10" mantel at the proper clearance from the top of the FP opening you will not have any problem. The mantel deflefts/pushes the heat away from the TV screen, I would also always use the blower to help move the heat away from the area. I would not make that brick recessed cavity for the TV though. My local appliance dealer reccomends not putting plasma TVs into alcoves like Freeman described for cooling reasons as mentioned. So just hang the plasma TV on the wall above the mantel. Or you can step your entire wall back above the mantel, just dont bring the walls back out all around it.

 

[MountainStoveGuy]

I dont think i would take the chance on ruining a expensive tv, you will always hear that its ok, but the AV specialist will tell you it wont, and alot of times the manufacturs will void the warrenty. I dont have to worry, plasma tv's dont work in altitude, weird huh.

 

[Corie]

really?


that's weird, i had no idea msg

 

[mlouwho]

I have an RSF Opel burning right now, it has been burning constantly for the last 3 months. I am using a digital thermometer to check various temps throughout the room.

Ambiant room temp, 73
Ceiling temp, 71
Wall along side of FP(installed across corner), 74
Wall on other side of room, 72
Next room over, 72
Next room after that, 70
Air coming from FP blower, 146
Bottom of wood mantel, 111
Top of wood mantel, 71
Wall above mantel, 70

As you can see, there is actually less heat on the wall above the fireplace than there is on the other side of the room. There is no reason not to mount a plasma TV there.

 

[MountainStoveGuy]

agreed, its all about air temp. If your air above your firepace is 70 degrees there is no problem. I can say this is not typical. There is no blanket statement saying you can or cant use a tv above a fireplace, but most walls above a fireplace can get in the low 100's, every situation is different, yours is unique.

 

[freeman.public]

Wow, I am very impressed with all of the advice - Thanks!

Well, I have been working with my architect, and the idea of a woodstove chimney is out. We are definitely building a full fireplace for the insert. I still have a few questions:

1. I don't want to place a mantel below the plasma, as I don't want the screen up very high. I see plasma screens above a traditional mantel, and the bottom of the screen is almost 5' off of the floor. I would like the bottom of my screen bottom to be no more than 42" off of the floor. The surround for the insert is 30" tall, and I plan to build the fireplace at floor level. I planned on having four courses of brick between the top of the insert surround and the box for the plasma. I also planned in having a 1/4" in gap (supported with a steel beam) somewhere in this four course face to stop the conduction of heat through the brick. I thought that by recessing the plasma (say the face is 2" behind the face of the brick) that I would avoid some of the rising heat. I will have a couple of inches of space on either side, a foot in the back, and a foot above the screen for ventalation. Since this is a custom installation, I can place a temperature controlled fan in this box to draw air from another location. I was thinking of having the controller turn on the fan at 95 degrees (plasma screens can operate up to 104 degrees now). The controller (I already have a spare from my aquarium) will then alarm if the temperature hits 104 degrees. Does this sound reasonable?

2. I have the option of using a double walled steel shell for the inside of the fireplace. This box is similar to the old heatalator units, provides the box and ash shelf, and is desinged to be build into a masonry fireplace. This box has holes that can route the air from between the steel shells wherever you would like. (I often see these with vents just below the mantel.) I was thinking of using this unit, and making the vents to either side of the fireplace (just to the ouside of the recess for the plasma screen). Is this a good idea? Are these shells a good idea in general or should I just go with a firebrick box?

3. My builder is suggesting a double walled stainless steel flue liner instead of a clay tile. I will likely run a brick chase. The insert will have a 6" insulated stainless steel liner either way. Is there an advantage of one over the other?

Thanks in advance.