Is condensation normal on horizontal venting?

[icefisherman]

I installed a heater this fall with a horizontal vent going through my sheetrock/insulation/osb board/vinyl siding. Tonight when I ran it for a little while is was 15 degrees f outside and about 40 degrees inside. I warmed it to about 50 degrees and I noticed condensation running down my wall. Is there anything I could do to stop that? On the outside of the garage I sealed up the thimble with caulking but not the inside. ( maybe my problem?) I did notice it was really windy and I could feel cold air blowing in around the thimble. I just dont want it to get between my wall and rot anything out.

 

[krooser]

Not sure what kind of heater or vent you used but I would think that keeping it a little warmer in the garage would keep the vent warmer and you'd burn off any moisture accumulating on the vent.

I have an 80K gas fired tube heater and, according to the manufacturer, it could actually have moisture at the inside end of the 40' tube if you don't keep her cranked up... I've never seen it but they do aluminize those things for a reason.

 

[Kevin54]

Most heaters with a horizontal exhaust require that the pipe be tipped slightly and have a drip leg installed.
You will want to seal everything up. Do you have "B" vent and thimble going through the wall where you can have insulation right up against it? If you are getting air infiltration through and it is cold, when it comes into contact with the warm pipe it will condense. Is it sweating on the outside of the pipe or through a joint?
On the other hand, is the heater going to be shut completely off and only turned on when you are out there or can you turn it down to say 50 degrees? If it is left on, even on low, it will take care of some of the moisture in the area and the vent will remain warm and keep condensation dried up. If you go from extreme cold to warm you will probably have a repeat of this problem. One other alternative would be to maybe use a pipe wrap to absorb the moisture and keep it from running down the walls or inside the wall

 

[icefisherman]

I have a 45000 mr heater and I have the class b vent rise alittle like it said to do. I am going to keep it at the minimum 38 till I go out there and turn it to maybe 60. I think it might be condensating on the inside of the wall running back into the garage, on the outside of the vent.