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Cooling air and Heating. Share your approaches.

Freemasm

Well Known Member
I'm taking Vince's recommendations and utilizing one each NACA inlet on the bottom of the wings. Ventilation here in hot AF Florida is important to say the least. That said, I'll also install a heat box and/or heated seats for elevation/winter travel out west.

- Can anyone please share their approach/ducting layouts?
- Did you have individual ducts to each occupant/seat?
- Did you tee off one to allow "double" flow to the pilot seat when no back seater?
- What would you have done differently?
etc.

I'm running out of room under the floor, aft of the aileron tubes. Your ideas and experience are appreciated.

Much thanks
 
My set up is pretty standard for the time that it was built. I have a NACA inlet on either side of the fuselage upfront which feeds eyeball vents on either side of the panel. The rear seat has an eyeball just ahead of the stick which is fed by an under wing NACA vent. The air coming in from the two front vents is noticeably warmer than from under the wing. Most likely from air spilling out the cowling inlets and traveling down the side of the fuselage. For cabin heat I have a heat valve connected to one of my two oil coolers. This feeds a single eyeball located below the panel.
 
My set up is pretty standard for the time that it was built. I have a NACA inlet on either side of the fuselage upfront which feeds eyeball vents on either side of the panel. The rear seat has an eyeball just ahead of the stick which is fed by an under wing NACA vent. The air coming in from the two front vents is noticeably warmer than from under the wing. Most likely from air spilling out the cowling inlets and traveling down the side of the fuselage. For cabin heat I have a heat valve connected to one of my two oil coolers. This feeds a single eyeball located below the panel.

I have the same setup in DFW Texas where the summer heat is brutal. I also use a head band as I think Elton John got all the glasses with wipers on them.
 
Standard rear seat : an eyeball ahead of the stick fed by an under wing NACA vent.
Front: two holes on the leading edges of the wing fairings, the right one fed an eyeball just under the corner of the panel, the left one fed a box, valve operated, putting air on pedals and electronic. The system do not suffer from the hot boundary layer around the cowling. A 30mm hole is enough.
A couple of knots before stall the two holes begins to bellow, an unexpected positive side effect!
To avoid excessive heat transfer from the motor side to the cabin, I installed a double insulation, internal and external on the FW.
 
Pilot cooling/heating

I tried those ‘gun ports’ hoping they would work - I guess your eyeball engineering is better than mine! I had to close those off and go with some small bluff body scoops, as seen on some WW2 big iron. These scoops seemed to attract our local mud dauber wasps, so I had to cover them with 1/8” hardware cloth. I ended up doing all the scoops as those wasps are very observant.

But one thing caught my eye: insulation on the inside of the firewall. Before Dan Horton pops in, did you do a burn test on the inner layer?

Also: don’t forget to let the air out. I added a reverse bluff body outlet on the aft inspection plate to help let the air out - I’m thinking of adding another. The aft PAX gets good air from the bluff body inlet in the inboard wing inspection panel (Evo wings on this one).

My plane is very warm no matter what - it is socks and shorts at 17500’ @ 5F. So, you can see what I am fighting at the lower altitudes. I added 2 ea bluff body scoops just behind the firewall, just above the upper longerons. One runs to the left eyeball; the other simply blows into the fwd area to keep the electronics happy. This ALMOST does the job.

Otherwise, I fly as high as practical here in Texas - trying to get some of that cooler air at altitude: generally 8500MSL at minimum. With the TCM 550 up front, I can get there rather quickly...

Formation work requires a bottle of water immediately after landing...maybe two... I do recall seeing the Dynon “greying out” during the first few flights when the ship was new - I had to fix that pronto as the pilot was also greying out..

Standard rear seat : an eyeball ahead of the stick fed by an under wing NACA vent.
Front: two holes on the leading edges of the wing fairings, the right one fed an eyeball just under the corner of the panel, the left one fed a box, valve operated, putting air on pedals and electronic. The system do not suffer from the hot boundary layer around the cowling. A 30mm hole is enough.
A couple of knots before stall the two holes begins to bellow, an unexpected positive side effect!
To avoid excessive heat transfer from the motor side to the cabin, I installed a double insulation, internal and external on the FW.
 
Hi Mark,
I certainly did not conduct careful and systematic tests like Dan's but I did something. The most difficult problem is finding an internal insulation glue that does not produce toxic fumes up to 600 ° C. Use the ceramic glue.
Find the tests I did at the link below. The names of the files explain the images.
The inlets on the wing fairings were copied from DocThrock, I put stainless steel wool at the entrance, it can be easily extracted from the outside. A siphon, obtained by bending the duct upwards, prevents the entry of water even with heavy rain.
Claudio
https://www.dropbox.com/sh/ctbi8vg7cwjyxa9/AAAwpZYRN0sE8ajuUWl2GztKa?dl=0
 
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