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It seems that flying at night, I typically have a cold cockpit. Last night I took a couple of photos. My wife had turned the temp way up but even after several minutes there was not much change to what we were feeling. What I don't understand is the massive difference in temp between the left and right HX (99C vs 5C). Is this typical?

I played around with turning the A/C to manual and then off and finally it warmed up on the right side (see next photo where it is 100C vs 66C). But the response was so slow I'm not really sure if that was due to turning it on and off or just having it finally get around to warming up.

Do others see this or should I be having this looked at?

Thanks!

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(Username Protected) - I have experienced the same. My trick is to start bringing in the heat when passing through 10,000 and up to half way on the dial when at FL180 and above. Keep the fan speed on low unless really cold then full heat and high fan speed to warm it up. You have to stay ahead of the temp on the climb up at night increasing as you climb to higher flight levels. Others may have another trick or two …

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Rob-

Take a look at the first picture's set/ actual cabin temp. Your wife has asked for 73F and the system is measuring 77F. In an attempt to match the temps, the duct temperature was driven down to 41, and the Vapor Cycle system has powered up to assist (Green VCS symbol). You were running AC for a while, it appears.

The 77 degree number is measured in the lav, so if the door is closed there is going to be poor feedback to the temp controller of actual cabin temp:

"The cabin temperature sensor which is installed on the cabin
evaporator is responsible for this behavior. As the cabin evaporator is
assembled on the area between the lavatory and the aft pressure
bulkhead, when the rigid door is closed, the return air from the cabin is
blocked causing a cabin and lavatory temperature equalization
impediment."

In terms of cockpit, 100C duct temp is a good as you're going to get. The VCS being on definitely was hurting you, but I have found the plane can lose heat at night in the cockpit faster than it can be replaced.