Originally posted by lytrytyr Do you know how the temperature is regulated in the shipping companies' cargo planes?
As a matter of fact I do. I taught those systems for many years. NO TURBINE EXHAUST GASES ARE INVOLVED IN THE CABIN ENVIRONMENTAL AIR SOURCES!
In simple terms, a small jet turbine drives a
separate compressor stage turbine that compresses and heats outside ambient air to 200-300 deg F. It's then passed through a de-compression stage to cool it to just above freezing. The two air sources are then mixed to produce thermostatically controlled, cabin and cargo compartment zone temperatures between about 40-80 deg F.
There's no reason
not to regulate temperature to a healthy, comfortable level since the same environment is shared by the flight crew -- cargo or otherwise.
Note that the process lowers humidity to an unhealthy level. If there's not a load of sweaty, exhaling humans to re-humidify the air in passenger service (HEPA-class filtration is used), humidifiers are employed to satisfy crew health needs. Environmental systems are essentially identical in both passenger and cargo aircraft - one design suits all purposes.
The temperature issues are not with a normal aircraft in flight, but with unregulated cargo bay conditions on the ground in hot or freezing weather. Any environmental system failure in flight will soon have the aircraft on the ground.
If temperature and humidity aren't
very well controlled in any aircraft, excessive condensation forms on the INSIDE of the aluminum hull. Over time that soaks the insulation, adds tons of weight, freezes/thaws, grows nasty fungus and causes really bad corrosion problems.
Myths and BS aside, if something happens to you or your belongings in flight it will be because of human failure or unanticipated mechanical failure, sort'a like havin' the UPS truck T-boned by a train; not an intentional design decision. The crews that fly aircraft every day are far more concerned, and knowledgeable, about health and safety matters than the average Pentax user and we don't knowingly put ourselves at risk.
H2
More than you wanted to know, eh??