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[powerstroke]

Been busy over the summer and did some things to my owb.  I pulled all of the insulation out of the sides and top and replaced it all with 2" foam board.  Did the bottom also.  I wanted to be able to remove this should the need to ever weld on it arises.  I put in a Ranco t-stat and also put in a variable speed fan control.  I already have the solenoid flap on there but I think that the fan doesn't need to run wide open all the time.  Maybe half speed?  I am going to play with this when I fire it up and see if i can tell any difference in wood consumption.  Has anyone done this mod?  I think the polystyrene insulation will really make a huge difference.  My water temp was 87 degrees when I did this and after 3 days of lows in the upper 40s and highs in the low to mid 70s it only dropped down to 84 degrees.  Wow!  I will try to post some pics soon.

[mikenc]

I would say the insulation will make a big differance. I don't have a shaver but had thought about putting a speed control on fan. Got to looking on fan and it said not to operate using speed control. Something you might check on your fan. I just decided to control air flow with solenoid and damper. My damper is attached to suction side of fan on one side .I only have mine open about 1/4 inch. If you open it much more it blows a lot of heat out flue.

[Scott7m]

Hmm...  what did the shaver have on it for insulation in the first place?   

most foam board isn't very good insulation, like R5 or so, most furnaces have like R30.  Another important thing is a good radiant barrier.

[gandgracing]

I have the damper to go over the intake side but blocking off some of the fan seemed as though the fire wouldn't get as hot.  My 250 had a 75cfm.

[willieG]

a few of the stoves have a slide control on the out side of the fan that you can adjust  for how much air gets in to the stove...it is not recomended by most manufactures to throttle a blower on the suction side but i guess if youhave no other option you do what is needed

[powerstroke]

It had fiberglass insulation around the jacket.  From the jacket to the exterior sheeting their is about 2 1/2" of space.  It swells out a bit in the middle of the furnace due to the water pressure pushing on it.  While there was plenty of insulation on it, fiberglass insulation is only 3.2 to 3.8 r-value per inch.  This polystyrene was 5 per inch.  From what I have been told and read numerous times there is absolutely no comparison.  Polystyrene is the ultimate in r- value.  You could take an r 50 value batt and compress the hell out of it in a 3 1/2" wall cavity and still only have an r 13 value.  Another plus is that it were to ever boil over on a hot day (I had this happen only one time) it wouldn't soak the hell out of it.  Wet fiberglass is extremely poor at insulating.  I did however lay the factory fiberglass blanket and radiant barrier over the top of the foam on the topside.  So my thinking is that if your stove uses fiberglass as an insulator and they are saying it has r-30 value you would have to have approx. 8 inch thick sidewalls and if I had to bet my life on it I would say NOBODY has a stove with that much space between the jacket and exterior.  On top maybe but no way on the sides.  Just my 2 cents......for what it's worth anyway.    Lol!

[mikenc]

a few of the stoves have a slide control on the out side of the fan that you can adjust  for how much air gets in to the stove...it is not recomended by most manufactures to throttle a blower on the suction side but i guess if youhave no other option you do what is needed

I have heard that from several different sources. My stove came from factory with suction side dampered. Has dayton fan on it. Lasted 2 seasons so far, bought an extra just in case.

[RSI]

a few of the stoves have a slide control on the out side of the fan that you can adjust  for how much air gets in to the stove...it is not recomended by most manufactures to throttle a blower on the suction side but i guess if youhave no other option you do what is needed

I have heard that from several different sources. My stove came from factory with suction side dampered. Has dayton fan on it. Lasted 2 seasons so far, bought an extra just in case.

Is your stove pre 09 model year? They have it and the output side on them from 09 and up.

[mikenc]

Bought Feb. 09. Guess mine was made before change. Has worked ok so far. Will see how long fan last.