Cabin Heater
Duct tape & cardboard are great for making a test version of the heater.
One of the benefits to using a liquid cooled engine, is convenient, efficient, clean cabin heat. Plumbing in a heater hose is simple and far easier than ducting in a heat muff.
I found a good aluminum heater core at the auto wreckers from a new wrecked Accent. Building a plenum to hold the core was simple enough and allowed me to have some control of where the heat was ducted. Ram air from both NACA ducts is brought in to the heater box via 2" scat tube, to the cold side. A 3/4" scat tube is fed from the cold side to the electrical compartment. the hot side of the heater box feeds 2 scat tubes to eyeball vents on the panel, and has a cable operated damper for floor heat. Defrost fans on the underside of the glare shield are 12 volt computer cooling fans (cheap & light). They draw air from under the panel. I chose to have fans for this in order to clear the canopy while on the ground, as ram air from the heater won't be reliable during taxi.
Temperature is control by a cable operated valve. Cable's are from a manual choke conversion kit available from auto parts store for approx. $7 cdn. The kit comes with a bunch of other parts that are useless, but the cable is perfect (cheap, light & sturdy) for operating the temperature valve & the floor heat damper.
I expect this to provide me with more than enough clean "CO free" heat to make the cabin plenty toasty even during winter flying in the Canadian north.
February 04, 2003
Heater plenum with aluminum core. Cold air enters the top from both sides. Small hole on top, right side sends cooling air behind panel. Heated air leaves bottom on both sides
Damper on the bottom is cable operated to provide floor heat.
Heater in place in front of the sub-panel
Top view shows black SCAT tube bringing cold air from NACA ducts. Orange/black SCAT tube carries hot/cold air to panel vents.
Cable operated heater valve controls cabin temperature, via a push/pull knob on the console.
Firewall penetration of fuel lines & heater hose.
5/8" heater hose fits tightly inside 1" hose with RTV to ensure a tight seal. 1" hose is inside a very close tolerance hole in the firewall. Both sides are ProSealed to make a permanent seal.