Replies

1. 
   Mooney | Dec 22, 2003 02:38pm | #1

   Wow , you sound dangerous .

   You probably have tripple wall pipe which would never get hot . Since you are using gas logs and it was meant to burn wood it looks like you could be safe . Can you post pics of the pipe ?

   Tim Mooney

1. 
   TwoCybers | Dec 22, 2003 05:29pm | #4

   No pics -  I cut  2 inch holes with a hole saw and plugged them with grommets.  My mantle is sticks out in the room and there are shelves on each side of the fireplace.  The distance between the walls is about 80 inches and the flue is is the middle.  I measured as was surprised to "hit" the flue.  The flue ID is about 6 inches.  I figured I would be about 4 inches behind the flue -  So I may have a triple flue.  When I could not sleep while thinking about this last night, I got some Zip cord and wrapped in around the flue from my gas furnace.  The flue was between darn warm and HOT - but I could hold my hand on the furnace flue even after the furnace had been running for 45 minutes continuous -  furnace is 80,000BTUs input and gas logs are 42,500 BTU's max input.

   Two additional things  thing if it matters, the fireplace is one of these that is open in two rooms - and the flue is not off set as often happens with normal fire places -- I can see the cover when I crawl into the box.

1. 
   Piffin | Dec 22, 2003 06:55pm | #5

   Odds are that you have triple wall Class A pipe which is more common for metal fireplaces. The double wall uis more common with wood stoves. The triple wall can add 3" to the radius.

   The gas fixture only requires a B vent and combustables 1-2" separation, dedpending on your code. The pipe is possibly larger than required for elimination of the CO from the gas fixture, allowing it to run cooler.

   IMO< the two inner walls of your pipe qualify as a B vent with the third outer wall creating the separation needed. You are 'probably' OK.

   I would still upgrade the wirte to a high temp wire and if possible, enclose it in a conduit.

   But now here is the part that scares me about this physics experiment -

   The fireplace was originally built for wood burning. It has been converted to gas. What is there to stop it from reverting to a wood unit? Flue gases typically run around 600°F or more and you do not want them dropping below about 450°F or creosote will build too quickly. In a chimney fire, temps will run up over 2000°F.

   So chances are that somedayu in the future, someone will reconsider, and start burning wood in this unit and at some indefinite time after that, wonder why the speakers no longer work. Not much chance of danger to occupants though..

   Excellence is its own reward!

1. 
   Mooney | Dec 22, 2003 09:36pm | #6

   My thoughts exactly. Thats why I thought this could be dangerous. I thought maybe pics might show tripple wall which would make a difference to me.

   Tim Mooney

1. 
   Piffin | Dec 22, 2003 10:25pm | #7

   I did assumptions

   (yep, really on dangerous ground now)

   That it was triple wall from fact it is fireplace instead of stove and that it was further out from center than he anticipated.

   But he will likely take this wire out when he leaves too, no?.

   Excellence is its own reward!

2. 
   CapnMac | Dec 23, 2003 12:33am | #8

   What is there to stop it from reverting to a wood unit?

   Ok, I'm second-guessing your second guess (with all that entails, yada yada yada).  But, I'm thinking the "conversion" was to pull the old grate out, and just connect the previous log lighter up as the feed to the gas log unit.  In other words, no other changes were made to the FP (which also means that all parts are still correctly sized for wood burning).  That, of course, presumes that the original construction was to code, etc.

   This is not an uncommon "conversion" here in Texas.  The cost of a cord of wood and regular chimney maintence can be twice what the gas costs (and you don't have to store a 1/5th cord of wood all summer . . . )  The defect, in my eyes, is that they almost never seal the units and use outside air for the combustion.  Ok, for reuse as a wood burner, no fault/no foul.  Crummy for energy efficiency, though--very little heat added to the chimney breast, and expenxively heated inside air sucked up the chimney.  (Oops, must stop ranting.)

   Now, if, as I suspect, the fireplace is where the tv ought to go, it's the main obstacle for installing good audio/video stuff.  Sometimes, it is easier to run the flat speaker wire in a wiremould surfaced mounted next to the edge of the brick of the fireplace surround.  This eliminates worrying about heat rated a/v wire & cable.  The other probability is that there is a built in cabinet next to the fp.  What will not be ovbious sometimes is that there is a space behind the cabinetry which makes a much better wire chase than the chimney.

   Hope all of this info is helping (and not muddying the water).Occupational hazard of my occupation not being around (sorry Bubba)

1. 
   TwoCybers | Dec 23, 2003 05:26am | #9

   One Question and some comments --

   how would a picture of the flue help anyone determine if it was triple wall vs. double wall?  -- Based on ID from looking up with head in the fireplace and looking through the hole in the wall I made, it is certainly not single wall!

   Being a former Damn Yankee (Michigan and Ohio) I supposed I won't offend too many people, but there really are building codes in metropolitan Atlanta -  they call it the Southern Building Code.  When I dealt with codes, it was considered good.

   The fireplace is a metal job, designed for wood.  Pulte Builders built the development in 2000 and 2001 -  about half the houses were gas logs only and half were wood burning.   I bought the house as second owner and when I went to convert the fireplace lighter to gas logs, I discovered the gas line had never been hooked up -- it was capped in the wall.

   The obvious issue is temperature, so after thinking about it, I have decided to get a color temperature crayon set and make the flue.  Fire it up and see if it gets above 100 degree F.  If it does, then I can deal with the problem.

   Cheers

   Gordon Atlanta

2. 
   Piffin | Dec 23, 2003 06:25am | #10

   A picture from in the attic or from the roof top would probably make it easy for those of us experienced with such to ID whether double or triple wall. The joint is different for each and the view from above at the roof would be telling. You could even discover this yourself without a camera, but popping the chimney cap off.

   But no real need to sweat it or get nervous.

   CapMac, I hadn't thought about how rare trees are in Texas compared to how common Gas is there. But this unit under discussion is not in Texas..

   Excellence is its own reward!

3. 
   CapnMac | Dec 23, 2003 09:52am | #11

   I hadn't thought about how rare trees are in Texas compared to how common Gas is there

   LoL!

   Depends upon where the "where" is.  Up near Ruby, they are few and far between (they also have more than 90 hdd per year).  Towards the middle of the state they range from common to right common (cliffs rocks around elCid will be fewer, as will the valley & hill walls around Doug@ees).  Get over to the east side of the state, and they're practically an affliction (Piney Woods country is something to see after being down around Uvalde or Seguin).

   I've just seen a few of the conversions (and live in a 45-55 hdd climate).Occupational hazard of my occupation not being around (sorry Bubba)

2. 
   IMERC | Dec 22, 2003 02:39pm | #2

   a retired chemistry teacher

   Andy and rez are gonna want to have a conversation with you...LOL!

   Welcome to BT Gordon.... Enjoy....

   There is an excellant chance that the vynal will be melted and your wires shorted. There is the possibility that the flue is triple wall.

   Is there any way for you to put the wires inside of the wall.

   Where are you trying to get from and go to?There is a host of things to do. Rise the thermal resistence of the wire. (upgrade)

   Relocate. Use a different internal wall as a chase. Put them in an iside corner and cover them with a piece of crown mould. 

    

   Who ever invented work didn't know how to fish....

1. 
   brownbagg | Dec 22, 2003 03:59pm | #3

   I got double wall insulated pipe on my wood burner and up in the aatic you cannot keep your hand on it. proberly 150 degrees

   The best employee you can have but you wouldn't want him as a neighbor " He the shifty type"