Question about OWB (gassifier) and Storage

[hiker88]

I read a statement on another post today that I didn't understand and would appreciate clarification on. I didn't want to hi jack the other thread so I thought I would start this one here.

Someone made a comment that storage is not usually desirable with an OWB - even if it is a gassifier. Why is that? Couldn't you have an outside gassifier, but have your storage indoors (say, in my basement).

The reason I ask is that I really want to convert to a wood boiler system but my house does not have a chimney at this time. Part of my problem is that I have a home with a small heat load and that it will cost between 4-$6,000 to have a chimney installed and this really extends the pay back time on this project.

I won't consider any inefficient boilers, but if I could avoid the cost of a chimney and avoid idling I think that would be a great help.

I appreciate your feedback.

 

[flyingcow]

My first thought was down time between burns. depending on how big your storage is, are you in danger of freezing the OWB? But glycol would be an easy fix for that. I do not know the pro's and cons of using Glycol. Others will chime in soon.

 

[Singed Eyebrows]

I read a statement on another post today that I didn't understand and would appreciate clarification on. I didn't want to hi jack the other thread so I thought I would start this one here.

Someone made a comment that storage is not usually desirable with an OWB - even if it is a gassifier. Why is that? Couldn't you have an outside gassifier, but have your storage indoors (say, in my basement).

The reason I ask is that I really want to convert to a wood boiler system but my house does not have a chimney at this time. Part of my problem is that I have a home with a small heat load and that it will cost between 4-$6,000 to have a chimney installed and this really extends the pay back time on this project.

I won't consider any inefficient boilers, but if I could avoid the cost of a chimney and avoid idling I think that would be a great help.

I appreciate your feedback.

You can have storage indoors, I don't think it's as convienent as having it right by the boiler. A Garn makes a nice OWB, typical installed cost can reach $20,000 though, chimney not required. I would look into a Wood Gun(gasification) boiler, they will power vent(no chimney). You could put this in a small homemade shed or buy a shed from the local farm & barn. The WG is a real nice boiler & they have the option of a stainless steel(extra cost) one also, Randy The WG will tolerate small heat loads better than any boiler I have heard of because it has 100 percent shut off of intake air on statisfied thermostat.

 

[maple1]

I think the main reason is the aforementioned freezing possibility. With storage there might be extended periods of no flow. I'm sure that could be overcome though - I am quite sure I would be putting storage in my basement if I had an OWB.

 

[stee6043]

Well first of all.....did you get a quote for that chimney? I installed my own chimney with 24 feet vertical (with a finished, sided chase) for a LOT less than $4,000. And that includes the cost of having a 9" hole cored in my basement wall and all the materials which are readily available at your local Menards store.

For what it's worth, I'm the guy you quoted above.

One big reason for me saying storage with an OWB is "not desirable" is due to the fact that the point of storage is to let a boiler burn full bore, peak output, and then go out. So first, would anyone want to have to start a new fire in an OWB every day, rain or shine? The fire starting process is something most of us indoor guys have come to enjoy but it usually requires a couple trips to the boiler. If you have to go outside I can only imagine the process being a huge PIA.

But more important than starting the fire is the cooling that would occur any time an OWB were to shut down. Even if freezing is never a concern the heat loss from an OWB not burning mid-winter is going to be tremendous (I would guess). Every time you start a new fire in the OWB you're going to have to put all that heat back into the water before it's usable in the house. This is much less of a problem for boilers living at room temperature in the basement with no wind. And even when we do lose BTU's we lose them to our homes, not to the great outdoors, so it's really not loss at all.

In my humble opinion the only convenient way to run a true OWB is with it smoldering alllllll dayyyyyy long, as they are designed to do. And last of all, storage is mostly a convenience feature with a very slight impact on efficiency for a properly sized system. I dare say the convenience of storage would quickly be eroded by having to manage the issues that would go along with an OWB burning out every day.

Just my two cents. I don't sell these things and I'm not an expert on anything.

 

[stee6043]

I read a statement on another post today that I didn't understand and would appreciate clarification on. I didn't want to hi jack the other thread so I thought I would start this one here.

Someone made a comment that storage is not usually desirable with an OWB - even if it is a gassifier. Why is that? Couldn't you have an outside gassifier, but have your storage indoors (say, in my basement).

The reason I ask is that I really want to convert to a wood boiler system but my house does not have a chimney at this time. Part of my problem is that I have a home with a small heat load and that it will cost between 4-$6,000 to have a chimney installed and this really extends the pay back time on this project.

I won't consider any inefficient boilers, but if I could avoid the cost of a chimney and avoid idling I think that would be a great help.

I appreciate your feedback.

For what it's worth here is a shot of just how easy a chimney can be. I don't recall exactly but I'm quite certain this was in the $1,500 ballpark by the time I buttoned it up.

 

[hiker88]

I guess it makes sense now that I think about it. I watched a video today of the classic boiler and the start up process seemed a bit involved. I much prefer the thought of having the boiler in the basement - especially if I want my wife to start it in the evening when I am not home.

Stee, maybe I can get some more info on how you pulled that chimney off. The first quote I got was for a metal bestos (sp?) chimney and that was around $3900. The next guy I had come out talked me out of metal bestos because I was talking about installing a wood boiler. He said that due to the low stack temps, condensation would be an issue (I'm looking at 33' feet of outside chimney). Even though about 14 feet of the chimney will be in the garage, it's unheated and is essentially outside. He does metal bespos as well, but said I would be better off with an Isokern chimney due to its high R value and light weight. The isokern blocks, thimble and chimney cap are $3,000 the rest is labor. I can do a lot of the labor, but that's why I estimated 4k. He quoted me $6,000 to do the whole job.

There's a lot of labor because I need to cut a whole through my garage floor, sink a caisson down about 5 feet and pour a pad to start building the chimney on, then cut two holes through the basement wall for the thimble and a clean out door. Then cut through the garage roof, second story eave, flashing etc. etc.

I guess this project getting off the ground really centers around pulling off the chimney. If the house had been built with one, this would be a done deal for me. This probably isn't the right forum for chimney discussions, but any ideas are appreciated.

 

[maple1]

I'm not sure why you would need to do any construction work below your garage ceiling or trusses to put in a chimney. If going up from inside thru the roof that is. If going out then up, check stee's pic out - no caisson there. A picture of where you are thinking of would likely help.

 

[hiker88]

The construction work isn't under the garage ceiling - it's under the garage floor actually.

To maintain my "clearance from combustibles" with the stove pipe in the basement, I need to be a certain amount below the ceiling joists. I think it is 9 inches with double wall stove pipe. Then I need to have a certain amount of distance below that to cut another opening in the foundation wall for a clean out door. The wall that this would take place is the wall on the garage side of the home.

So I need to cut a rectangular opening in the garage floor slightly larger than the size of the Isokern blocks and dig down about 5 feet. This will give enough height to pour a cement pad to start buidling the chimney on. I have to sink a caisson as I dig down to prevent the dirt from under the rest of the garage floor spilling into the hole and weakening the garage floor. I think he said it would take 4 or 5 blocks to get up level with the garage floor. One of the blocks would line up with the thimble hole punched through the wall and into the basement, and the other block would line up with the hole for the clean out door. Then I would go up the garage wall which abuts my house, to the garage ceiling. I'd have to cut and "sister" one ceiling joist to make room for the chimney on the way to the ceiling, cut though the ceiling roof, go up the side of the house, and then through the eaves on the top floor.

So, I'm working under two conceptions that maybe aren't true.
1) That I need an Isokern type chimney for use with the wood boiler due to my long run (33') and the low stack temps associated with the boiler (to avoid condensation and creosote). You can only get Isokern through the installer, they won't sell to me directly. If I can use another type of chimney material that would not have condensation issues and that I can install myself - I'd be all over it. The other thing with the Isokern is that it is joined with a mortar mix that I'm not really comfortable doing myself, so I would need to have the installer build the chimney. He told me if I hump the blocks for him, he'd "pay" me $15hour, but I'd like to do this project on my own as much as possible.

2) That I can't build the chimney up the back of the house because the weight of snow sliding down the roof and resting against the chimney is not good. If I could go up the back of the house, I wouldn't have to deal with the garage floor.

I can shoot some video and post it somewhere for people to give their opinion on if that sounds good. I'm going to see if there are any other chimney threads on the forum too. What do you guys think?

I really appreciate the feedback. Unbiased opiniomns are invaluable.

 

[maple1]

I guess maybe some pics or a drawing might help - I was thinking you were talking about putting the unit in the garage. Still not sure on the setup you are describing.

I've never heard of Isokern - but I think every wood burning appliance I have heard of could be vented into a typical Stainless ('Class A') chimney. Here is a recent stove chimney thread that has a couple of links in it to more chimney info:

https://www.hearth.com/talk/threads/88988/

 

[Noggah]

Hiker,

That sounds very involved. If you would like to see my CB E-Classic in operation PM me. I am about twenty minutes from you. I am going add storeage to mine. The stove will maintain itself between burns. The controls allow for this. I don't have a chimney and the prices your looking at will cover most of a small e-classic install.