Trim air 737ng

[McBruce]

While on this subject it reminded me of a previous question I tried to find an answer to concerning the -800.

The gasper air valves in the cockpit, is this mix manifold air or air coming from the cockpit feed from the left pack?

[de facto]

The flight deck Air comes from the Left pack via a separate duct than for the pax so does not use recirculated air...it does not enter the mix manifold.
Fresher air for us.

[Dougie_diesel]

A word from the experts...............

Here's what Mr. Boeing has to say on the matter.....

Zone Temperature Control
This part of the A/C system increases the temperature of the conditioned air that flows into the occupied areas of the airplane. It also gives pressure regulation and on/off control for the trim air part of the system. These are the primary components:

• Trim air pressure regulating and shutoff valve

• Zone trim air modulating valves

• Temperature sensors.

The system calculates the necessary pack outlet temperatures to satisfy the cooling needs to the flight compartment and the mix manifold. The system also calculates the heating necessary for each temperature control zone. These are the temperature control zones:

• Flight compartment zone

• Passenger cabin zones (2).

Air from the pneumatic system adds heat to a zone that needs warmer air. The trim air pressure regulating and shutoff valve gives on/off control and keeps trim air pressure at a necessary limit.
See the trim air pressure regulation and shutoff control section for more information about the trim air pressure regulation and shutoff control systems. (SECTION 21-60)
The zone trim air modulating valves control the heat added to the conditioned air for each zone.
See the zone temperature control section for more information about the zone temperature control systems. (SECTION 21-60)
Zone Temperature Control
This part of the A/C system increases the temperature of the conditioned air that flows into the occupied areas of the airplane. It also gives pressure regulation and on/off control for the trim air part of the system. These are the primary components:

• Trim air pressure regulating and shutoff valve

• Zone trim air modulating valves

• Temperature sensors.

The system calculates the necessary pack outlet temperatures to satisfy the cooling needs to the flight compartment and the mix manifold. The system also calculates the heating necessary for each temperature control zone. These are the temperature control zones:

• Flight compartment zone

• Passenger cabin zones (2).

Air from the pneumatic system adds heat to a zone that needs warmer air. The trim air pressure regulating and shutoff valve gives on/off control and keeps trim air pressure at a necessary limit.
See the trim air pressure regulation and shutoff control section for more information about the trim air pressure regulation and shutoff control systems. (SECTION 21-60)
The zone trim air modulating valves control the heat added to the conditioned air for each zone.
See the zone temperature control section for more information about the zone temperature control systems. (SECTION 21-60)