Question about cold air intake in doublewide.

[FeedThatJones]

Hey guys, new member here with a question. I am getting ready to install a nc13 in a doublewide. Im going by the instuctions provided as the county i live in and our insurance said to do. My question is, where im installing the stove isnt against an outside wall. So the cold air has to come through the floor and hearth. Does it need any airspace around the ducting? My manual does not state that it has to have an airspace so im guessing i should be ok without it. Also do i need to run some type of sleeve to keep condensation from affecting the hearth materials? My hearth is going to be made of 3/4" plywood, two layers of 1/2" micore 300 board, 1/4" layer of hardibacker then tile. I may put a piece of thin guage sheet metal between the hardibacker and micore board to help distribute the weight from the stove.

Thanks for any help guys and gals.

 

[begreen]

Welcome. The outside air kit intake pipe runs cool. It does not need any insulation or air gap around it. I would use a couple layers of 1/2" cement board for the top layer under the tile for stiffness. Micore is soft and may flex under the weight of the stove. That probably will crack 1/4" underlayment and in turn the tile grout. Durock NexGen cement board has almost twice the insulation value of Hardiboard.

 

[FeedThatJones]

Welcome. The outside air kit intake pipe runs cool. It does not need any insulation or air gap around it. I would use a couple layers of 1/2" cement board for the top layer under the tile for stiffness. Micore is soft and may flex under the weight of the stove. That probably will crack 1/4" underlayment and in turn the tile grout. Durock NexGen cement board has almost twice the insulation value of Hardiboard.

Is durarock common material locally avaliable at lowes, home depot, etc? I had to special order the micore from a local building supply. And thank you for the very quick response. Also, is running the cold air straight out of the stove and into hearth going to mess with the R value any?

 

[begreen]

Yes, look or ask for Durock NexGen. It's ok to take the OAK pipe through the hearth. No problem with the hearth R value that I have heard of though it's a good question.

What are the plans for the chimney? The stove is going to need two things to burn well. Fully seasoned wood and strong enough draft to pull air through the secondary tubes. To achieve good draft it is going to want 15' of flue system straight up or more if the chimney is on the outside and tee'd into.

 

[FeedThatJones]

Yes, look or ask for Durock NexGen. It's ok to take the OAK pipe through the hearth. No problem with the hearth R value that I have heard of though it's a good question.

What are the plans for the chimney? The stove is going to need two things to burn well. Fully seasoned wood and strong enough draft to pull air through the secondary tubes. To achieve good draft it is going to want 15' of flue system straight up or more if the chimney is on the outside and tee'd into.

Im going to use the duravent mobile home chimney kit with the triple wall stove pipe. I had planned on running single wall pipe from the stove to the chimney because im going to have to make a small horizontal run with two 45° degree. But i just seen they make triple wall angled chimney pipe. Does that mean i could run triple wall on the entire system and get it alittle closer to the wall? Alot more money though. We also plan on running tile to the ceiling behind the stove.

 

[begreen]

DuraVent makes a value line DuraPlus pipe that is triple-wall and a bulky 10" OD, and DuraTech that is their premium pipe that is double-wall and 8" OD. There are no 45 elbows allowed for chimney pipe, regardless of brand, only 15 and 30 deg angle elbows. Is the chimney going up through the roof or out the side and then up?

 

[FeedThatJones]

DuraVent makes a value line DuraPlus pipe that is triple-wall and a bulky 10" OD, and DuraTech that is their premium pipe that is double-wall and 8" OD. There are no 45 elbows allowed for chimney pipe, regardless of brand, only 15 and 30 deg angle elbows. Is the chimney going up through the roof or out the side and then up?

Up through the roof. We just cant have a straight run because of ceiling joist placement. The difference is going to be about 14.75". Im hoping this will not affect the draft to much.

 

[begreen]

Straight up is good. You can offset up to the ceiling. That part of the flue is with stove (connector) pipe. They make 45's for that pipe. An offset using a couple 45s shouldn't dramatically affect draft. Once you are at the ceiling the pipe has to transition to chimney pipe (class A). You'll want to go straight up from that point.

 

[FeedThatJones]

Straight up is good. You can offset up to the ceiling. That part of the flue is with stove (connector) pipe. They make 45's for that pipe. An offset using a couple 45s shouldn't dramatically affect draft. Once you are at the ceiling the pipe has to transition to chimney pipe (class A). You'll want to go straight up from that point.

Yes its going to be straight after the offset in the house. From rough approximate measurments i should meet all the requirements refering to chimney heights. If not im going to just throw on another section of the triplewall. I plan on using a support on the roof either way. It can get rather windy up on this moutain.

 

[begreen]

Sounds good. Keep us posted and take some pictures!

 

[FeedThatJones]

Ok so had alittle bump in the road. I went friday to get my durarock and micore 300 boards. But the delivery driver called in and the micore wouldnt be there until monday. The salesman said they stock a similar board with a greater r value just a different brand. He told me it would work the same as micore in a hearth. Its sound deadining fiber board with an r value of 1.3 per 1/2" thick. But halfway through construction i realize this board says "warning : combustible". Checked the website and it says not to use in fireplaces, chimneys, heaters, etc without adequate protection. Called this morning and he cancelled the order of the micore so it will be 2 weeks before i can get it. He still says i can use the board i got but im not sure. Im going to re-read my manual but im pretty sure it says the pad under my stove must be a minimum of 1" thick, r valve of 2, and built of non combustible materials. Any suggestions? Can i use the sound board or do i need to keep trying to source the micore 300?

 

[begreen]

Roxul makes a rigid board insulation that might work.
(broken link removed to http://www.roxul.com/products/residential/products/roxul+comfortboard+is)