Hi,

Two questions about using the heat to the cockpit from a muff around the exhaust pipe.

1.  Will the airflow from an intake air scoop be adequate or would I need a fan to draw the air
into the cockpit?
2.  Can I fabricate the collector box with dump valve from aluminium or must I use stainless?

Pierre
South Africa


It depends somewhat where the muff is. If it is close to the ports I would
use SS. These device are very dangerous because of CO. You have a water cooled engine
I would use an H2O heater core.

Paul Lamar


Okay, I have two aircon cores +\- 5" x 6" x 1.5" thk. Would one be sufficient or should I use both
and should I use a fan or just a NACA duct?

Pierre

What kind of airplane is it? Two place or four place?
One should be sufficient for a two place. A NACA duct with a butterfly valve
ought to do the job.
Keep it simple.

Paul Lamar

Paul,

Have you heard from anyone in an extremely cold climate that uses engine coolant for cabin heat?

You'll have to get the engine pretty warm before takeoff so as to have adequate heat to provide
defrost.  Frosting over on the takeoff roll can be hazardous and happen surprisingly quickly.

You might need a cowl flap so that you have adequate hot water during a long decent.  Not just to
keep your feet warm, but to keep the windshield clear of frost.

I have also heard that in extremely cold places, taking external cold air in through the heater core
may produce marginally warm air - when you want the hottest air.  At the least you'll have to keep
the coolant warm enough, but it might be worth figuring out how to do recirculation.

Winter is coming - in Idaho, anyway...  ;)


Regards,

Matt-

South Africa is not all that cold :)

Paul Lamar

I don't think that would be a problem here.The lowest our temp dropped this winter was +7C

Pierre