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From: n295v v



Stu, Our naca vent is located lower right side of the vertical stab.  Well, your information is partly right--in the winter it blows like a son of a gun, and the slide valve is certainly in order, cause it gets darned cold in the cabin.  Conversely, in the summer it blows like a son of a gun when the plane is going fast (not sitting on runway), but I find that the area under the panel exhibits high heating from all the instrumentation, so my recommendation is to make sure you run a cooling tube (or two) into the back of the panel, and the booster fan will certainly aid to move air under there.



I can't be at all critical of a booster fan--it will certainly help when you are on runway, and it will be of some help in 90 degree weather.



I guess my comments were more from surprise.  Since I have not received any revisions from the factory in what seems like eons,  my mushroom syndrome must be surfacing!  Did this suggestion come from the factory, or was it from another builder?



What did you use for a slide valve?  I recently added one to my IV--bought it from a large hardware store--it is one of those plastic jobs that is used in a dust collector for saws.  I saw a better one (more expensive) at a RV supply store that I felt would hold up better, but I have already installed the first one.



I ran a vernier push cable forward to the area between the wheel well from the slide valve. If the OAT deems it, I simply reach into the wheel well before departing, and adjust the slide valve accordingly. I had to be very careful to position the cable handle where it would not be touching the stored wheels in the wells.



I have not considered a booster fan because my vent blows really hard.  But, some planes might need it, especially those located in the southern states.  A nice addition might be to add an external electrical connector and a thermostat in the airplane.  When the airplane is in storage, fresh air could be pumped into it to lower the heat buildup.  Nothing is worse than getting into the plane in Texas in July.



What blower did you use?  How much does it weigh?  Has anyone made up a schematic of the Mac trim arrangement?



Alternately, I wish I had installed a second naca vent forward in the airplane.  It could have been used to cool the avionics stack and the fron cockpit area without adding weight to the airplane.



Good flying, David Jones, Pecatonica, Illinois

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