It’s a well known fact that the heating is not really very effective (but i do not know if it’s the same for all versions). In my plane it’s okay at -10 or -15 (I rarely fly in altitudes that are colder) … but I know that the passengers in the back seat tend to have cold feet.
Seems like it. I’ve browsed COPA and saw similar complaints. I will check all valves and outlets for tomorrow’s flight and also go shopping for ski clothing – if I can find it here in Barcelona at this time of the year :-)
60 liters of gasoline of which 30% is “lost” generating thrust still leaves you 70%, i.e. 42 liters of gasoline per hour to keep you warm. That is quite a lot for such a small cabin. Therefore it should be warm and cozy, shouldn’t it?
My aircraft has an extremely effective heater (it can melt plastic bottles) but only when the cowl flaps are closed. That means during a long climb in cold weather, I have the choice between freezing my b*** or frying my cylinders…
Stephan_Schwab wrote:
How good are cabin heaters? What temperatures one can expect? Where are the limitations?
Since you didn’t say, shall we assume your’e talking about a SR-22 ?
The heater in most SEPs is a simple heat exchanger on one or both exhaust manifolds.
This system relies on the temperature of the exhaust gases AND the air density.
It’s easy to see that in an NA (Normally Aspirated) engine the actual power output in the FLs is 50% or less, and since the exhaust heat is fairly proportional (all else being = ) to the power output.
Add to that the very low density of the air and voila, the efficiency of your heat exchanger is now a small fraction of what it’s capable of at say 6000’ .
achimha wrote:
60 liters of gasoline of which 30% is “lost” generating thrust still leaves you 70%, i.e. 42 liters of gasoline per hour to keep you warm. That is quite a lot for such a small cabin. Therefore it should be warm and cozy, shouldn’t it?
I believe the trip in question was at FL200 and in that case the fuel burn wad probable down to 30Lt/Hr.
My aircraft has an extremely effective heater (it can melt plastic bottles) but only when the cowl flaps are closed. That means during a long climb in cold weather, I have the choice between freezing my b*** or frying my cylinders…
Yours is a turbo which is basically an excellent heat factory ! 
(FYI: It’s a 22T)
To answer the question: SR22 turbo-normalized with enough heat to send towards the cabin – in theory.
Totally variable we have 3 Cessna 150/2. One if the 150 the heater is fantastic. One us OK but the C152 its awful. Almost upto the point whereno one will fly it over tthe winter.
Yet the whole system been apart and is supposedly in full working order.
achimha wrote:
I have the choice between freezing my b*** or frying my cylinders…
By restricting the cowl flaps to binary open/closed, the aircraft loses flexibility and comfortability. On the plus side it gains in simplicity but only marginally so.
tomjnx wrote:
By restricting the cowl flaps to binary open/closed,
I wonder why some airplane manuals pretty much recommend binary usage of cowl flaps.
Maybe it has to do with the lack of instrumentation (engine monitor) in the original panel and hence the inability to adequately monitor the CHTs?
