Cabin Heating in C525 series
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Cabin Heating in C525 series
Is there a cetified cabin heater for the C525? We are often at airports with temps at -20C and running one engine just doesnt warm up the cabin. Most of these airports just dont have external cabin heaters or 220v as well, so a regular car cabin heater wouldnt work either.
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My fellow CJ'er...
Are you sure your 1 engine technique doesn't work?
We don't have any problems with this method, you just need to remember to turn the air source select to (i assume) the right engine, and give it at least 15 - 20 minutes. Admittedly not tried it at -20C but works fine at -10C...
Are you sure your 1 engine technique doesn't work?
We don't have any problems with this method, you just need to remember to turn the air source select to (i assume) the right engine, and give it at least 15 - 20 minutes. Admittedly not tried it at -20C but works fine at -10C...
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We never tried the air sourse select to the right technique, since if we only have one engine the other bleed valve should be auto to off (shouldn't it). We'll try this technique te next flight.
Thanks for the info.
PD
Thanks for the info.
PD
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Does the CJ have a 'GND' position on the pressurisation source selector ?
If so, and with the right engine running, should give greater volume of bleed air available for heating. This is on the C550 and Bravo. Would be interested to know if this feature is on CJ'S.
If so, and with the right engine running, should give greater volume of bleed air available for heating. This is on the C550 and Bravo. Would be interested to know if this feature is on CJ'S.
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We never tried the air sourse select to the right technique, since if we only have one engine the other bleed valve should be auto to off (shouldn't it).
In ours it does make a slight difference to the heating effect by selecting the running engine...
Let me know if it solves your problem or not.
Cheers
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I checked the system in my FSI book and there should be a checkvalve preventing flow to the opposite engine.
Lucky for us we've been flying straight out of the hangar the last couple of weeks so no cold yet. but as soon as it cools down or we stay overnight i'll let you know. we also will be flying into FAB this week so i might pop in to FSI to ask one of the instructors
have a good week
PD
Lucky for us we've been flying straight out of the hangar the last couple of weeks so no cold yet. but as soon as it cools down or we stay overnight i'll let you know. we also will be flying into FAB this week so i might pop in to FSI to ask one of the instructors
have a good week
PD
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Selecting RH with the #2 running will not increase the airflow into the cabin.
UVW is quite right that the valves are fail safe open thus powered closed. With the battery energised and the throttles in cutoff the SOV's, however, will be powered closed. When moved out of cut off the valve is de energised and opened. The flow valve is also commanded to the higher flow position. When the remaining throttle is brought out of cut off the respective valve opens and both flow valves go to low flow. If an SOV should fail open they also have a non-return element to prevent loss of air into the opposite side. (there are variations of valve types and combinations throughout the CJ range but the operation is fundamentally the same).
On the ground, in auto temp contol and throttles below 85% if the cabin 'ground' temp sensor is greater than, from memory, 65degF the controller will not allow the SOV(s) to open preventing incoming warm air. Not an issue at -20 unless its defective.
You could try selecting manual temp control which overides this and see if makes any difference, just be aware of a possible duct overheat on 'warmer' days.
Another option is to advance the throttle a little, makes a suprisingly big difference to bleed flow and temp, again use caution.
6 years in a citation centre and I've never had a issue with on ground heating, but never say never!!
UVW is quite right that the valves are fail safe open thus powered closed. With the battery energised and the throttles in cutoff the SOV's, however, will be powered closed. When moved out of cut off the valve is de energised and opened. The flow valve is also commanded to the higher flow position. When the remaining throttle is brought out of cut off the respective valve opens and both flow valves go to low flow. If an SOV should fail open they also have a non-return element to prevent loss of air into the opposite side. (there are variations of valve types and combinations throughout the CJ range but the operation is fundamentally the same).
On the ground, in auto temp contol and throttles below 85% if the cabin 'ground' temp sensor is greater than, from memory, 65degF the controller will not allow the SOV(s) to open preventing incoming warm air. Not an issue at -20 unless its defective.
You could try selecting manual temp control which overides this and see if makes any difference, just be aware of a possible duct overheat on 'warmer' days.
Another option is to advance the throttle a little, makes a suprisingly big difference to bleed flow and temp, again use caution.
6 years in a citation centre and I've never had a issue with on ground heating, but never say never!!
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This is one of the best topics i have come across, cheers to all. As I am used to operating in 30-45 degree temps its great to have this sort of info for the odd flight into cold areas.
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FYI
Some Interesting stuff here for Citation techies!
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Forgive me, a few citation types but not the CJ's mostly with APU's, why not start the left and put the selector to emer, or is that squat switch inhibited.
lots of hot air in a hurry, noisy but effective
lots of hot air in a hurry, noisy but effective
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G-SPOT
That'll work on on the CJ3 but not the other 525 models due WOW inhibit. Not sure about the 525c CJ4 though.
Not very practical for the loading of PAX and also with relativly little precooler air (only idle fan bypass air) the duct temperatures will soon exceed normal 'EMER' operating temps, potentialy damaging components or worse.
Would probably be ok in short bursts of 30 secs or so but by no means approved. Make sure your rotary windshield bleed knobs are off, preventing EMER air loss onto windshields and the possible melting of said windows!!
Happy Heating
That'll work on on the CJ3 but not the other 525 models due WOW inhibit. Not sure about the 525c CJ4 though.
Not very practical for the loading of PAX and also with relativly little precooler air (only idle fan bypass air) the duct temperatures will soon exceed normal 'EMER' operating temps, potentialy damaging components or worse.
Would probably be ok in short bursts of 30 secs or so but by no means approved. Make sure your rotary windshield bleed knobs are off, preventing EMER air loss onto windshields and the possible melting of said windows!!
Happy Heating
