Things to remember in very hot weather

Stealth Pilot writes:

on the contrary it is a hell of a lot of fun.
just how long do you think it stays 43 C when you are flying for real?

Most of the flight, at moderate altitudes, or at least it stays too hot for
most of the flight. My baron has an "air conditioning" switch, but it's not
clear whether or not this is the real thing, since the real thing requires a
compressor.

"Mxsmanic" wrote in message
...
Stealth Pilot writes:

on the contrary it is a hell of a lot of fun.
just how long do you think it stays 43 C when you are flying for real?

Most of the flight, at moderate altitudes, or at least it stays too hot
for
most of the flight. My baron has an "air conditioning" switch, but it's
not
clear whether or not this is the real thing, since the real thing requires
a
compressor.

The "real thing" doesn't necessarily require a compressor.

Mike writes:

The "real thing" doesn't necessarily require a compressor.

So how does it work?

"Mxsmanic" wrote in message
...
Mike writes:

The "real thing" doesn't necessarily require a compressor.

So how does it work?

Some older planes had a non-compressor based system that required water. I
assume it was some sort of evaporative cooling setup. I lived in El Paso,
Texas where the temps routinely got above 43° C and I had an evaporative
cooler in my home that worked just fine.

You can also buy aftermarket systems that use ice.

Mike writes:

Some older planes had a non-compressor based system that required water. I
assume it was some sort of evaporative cooling setup. I lived in El Paso,
Texas where the temps routinely got above 43° C and I had an evaporative
cooler in my home that worked just fine.

That would be a swamp cooler rather than true air conditioning. It would work
in an aircraft if the humidity were low enough, but the weight of the
necessary water sounds like a major drawback.

You can also buy aftermarket systems that use ice.

Still not true A/C, but better than nothing.

I suppose adding a compressor to an engine would raise all sorts of issues
with certification, testing, performance, etc.

In article PTV9k.157$K%2.34@trnddc02, "Mike"
wrote:

"Mxsmanic" wrote in message
...
Mike writes:

The "real thing" doesn't necessarily require a compressor.

So how does it work?

Some older planes had a non-compressor based system that required water. I
assume it was some sort of evaporative cooling setup. I lived in El Paso,
Texas where the temps routinely got above 43° C and I had an evaporative
cooler in my home that worked just fine.

You can also buy aftermarket systems that use ice.

There are also state-change systems that just need a heat source to
drive them, like Dometic kerosene refrigerators. Not very useful for
aircraft use, granted.

On Jun 29, 7:23 pm, Steve Hix
wrote:
In article PTV9k.157$K%2.34@trnddc02, "Mike"
wrote:

"Mxsmanic" wrote in message
.. .
Mike writes:

The "real thing" doesn't necessarily require a compressor.

So how does it work?

Some older planes had a non-compressor based system that required water. I
assume it was some sort of evaporative cooling setup. I lived in El Paso,
Texas where the temps routinely got above 43° C and I had an evaporative
cooler in my home that worked just fine.

You can also buy aftermarket systems that use ice.

There are also state-change systems that just need a heat source to
drive them, like Dometic kerosene refrigerators. Not very useful for
aircraft use, granted.

Turbine engined airplanes don't have AC compressors. They bleed
some compressed air from the compressor stage of the engine, run that
through an exchanger to cool it, then drop its pressure, which lowers
its temperature a whole bunch. Mixing this really cold air with hot
bleed air provides whatever temperature the pilot wants.
A piston engine with a larger turbocharger could use some of
the same effect but it would be less effective since the pressures are
lower.

Dan

wrote in
:

On Jun 29, 7:23 pm, Steve Hix
wrote:
In article PTV9k.157$K%2.34@trnddc02, "Mike"
wrote:

"Mxsmanic" wrote in message
.. .
Mike writes:

The "real thing" doesn't necessarily require a compressor.

So how does it work?

Some older planes had a non-compressor based system that required
water.
I
assume it was some sort of evaporative cooling setup. I lived in
El Pas
o,
Texas where the temps routinely got above 43° C and I had an
evaporati
ve
cooler in my home that worked just fine.

You can also buy aftermarket systems that use ice.

There are also state-change systems that just need a heat source to
drive them, like Dometic kerosene refrigerators. Not very useful for
aircraft use, granted.

Turbine engined airplanes don't have AC compressors. They bleed
some compressed air from the compressor stage of the engine, run that
through an exchanger to cool it, then drop its pressure, which lowers
its temperature a whole bunch. Mixing this really cold air with hot
bleed air provides whatever temperature the pilot wants.
A piston engine with a larger turbocharger could use some of
the same effect but it would be less effective since the pressures are
lower.


Actually, some turbines do use compressers, like the old RR Dart, for
instance (they call it a spupercharger, it's a rootes type compressor)

The 787 is going back to them in an effort to get away from the problem
of cabin fumes...


Bertie

wrote in message
...
On Jun 29, 7:23 pm, Steve Hix
wrote:
In article PTV9k.157$K%2.34@trnddc02, "Mike"
wrote

There are also state-change systems that just need a heat source to
drive them, like Dometic kerosene refrigerators. Not very useful for
aircraft use, granted.

Turbine engined airplanes don't have AC compressors. They bleed
some compressed air from the compressor stage of the engine, run that
through an exchanger to cool it, then drop its pressure, which lowers
its temperature a whole bunch. Mixing this really cold air with hot
bleed air provides whatever temperature the pilot wants.
A piston engine with a larger turbocharger could use some of
the same effect but it would be less effective since the pressures are
lower.

Dan

Well...some turbine powered airplanes have AC compressors. The one I flew
had one, we used it to pre-cool the cabin and up to 18,000 feet. We also
used it as a de-humidifier when going into humid areas so the windshield
would not fog up.

--
*H. Allen Smith*
WACO - We are all here, because we are not all there.

On Sun, 29 Jun 2008 21:16:33 -0700 (PDT),
wrote:

On Jun 29, 7:23 pm, Steve Hix
wrote:
In article PTV9k.157$K%2.34@trnddc02, "Mike"
wrote:

"Mxsmanic" wrote in message
.. .
Mike writes:

The "real thing" doesn't necessarily require a compressor.

So how does it work?

Some older planes had a non-compressor based system that required water. I
assume it was some sort of evaporative cooling setup. I lived in El Paso,
Texas where the temps routinely got above 43° C and I had an evaporative
cooler in my home that worked just fine.

You can also buy aftermarket systems that use ice.

There are also state-change systems that just need a heat source to
drive them, like Dometic kerosene refrigerators. Not very useful for
aircraft use, granted.

Turbine engined airplanes don't have AC compressors. They bleed
some compressed air from the compressor stage of the engine, run that
through an exchanger to cool it, then drop its pressure, which lowers
its temperature a whole bunch. Mixing this really cold air with hot
bleed air provides whatever temperature the pilot wants.
A piston engine with a larger turbocharger could use some of
the same effect but it would be less effective since the pressures are
lower.

Or they can install a Keith style all-electric compressor rather than
the Malibu style compressor which is belt-driven off the engine next
to the alternator belts. Needs a beefy electrical system though, it
draws darn near 50 amps.