Ventilation

Question 1

Ventilation

How many equipment cooling systems does the 787 have ?

Answer 1

2
Forward ➔ Flight deck / FWD E-E bay / FWD Cargo
Aft ➔ AFT E-E bay / AFT Cargo

Question 2

Ventilation

In the override mode of the equipment cooling systems, what ensures Airflow ?

Answer 2

All fans being commanded off, the Airflow is provided through cabin differential pressure.
As the A/C descends, the cabin differential pressure decreases, reducing the airflow and cooling.

Question 3

Ventilation

In the override mode of the equipment cooling systems, are the cargo compartments still heated/ventilated ?

Answer 3

No, they are not.

Question 4

Ventilation

Placing which EQUIP COOLING switch to OVERRIDE would help with passenger cabin smoke evacuation ?

Answer 4

The AFT EQUIP COOLING switch.

Question 5

Ventilation

Placing which EQUIP COOLING switch to OVERRIDE would help with flight deck smoke evacuation ?

Answer 5

The FWD EQUIP COOLING switch.

Question 6

Ventilation

Can the Miscellaneous Equipment Cooling System be controlled ?

Answer 6

NO, its operation is fully automatic, but its power can be removed using the IFE/PASS SEATS switch on the overhead ELECTRICAL panel.

Question 7

Ventilation

What is the Power Electronics Cooling System (PECS) ?

Answer 7

It’s a liquid cooling system for the large motor power distribution system located in the aft E/E equipment compartment.
It also provides cooling for the integrated cooling system.

Question 8

Ventilation

How many liquid cooling loops does the PECS (Power Electronics Cooling System) have ?

Answer 8

The system consists of two independent liquid cooling loops.

Question 9

Ventilation

Is there a cool-down period for the PECS (Power Electronics Cooling System) during electrical power down ?

Answer 9

YES

• APU or both fwd ext power ON ➔ 10 minutes
• Only 1 fwd ext power ON ➔ 22 minutes

Question 10

Ventilation

How is the PECS (Power Electronics Cooling System) controlled ?

Answer 10

There are no flight deck controls.

Operation is fully automatic.

Question 11

Ventilation

What is the ICS (Integrated Cooling System) ?

Answer 11

Integrated with the air conditioning system and liquid cooling system, it provides cooling to galley carts and cabin air.

Question 12

Ventilation

How is the ICS (Integrated Cooling System) controlled ?

Answer 12

There are no flight deck controls.

Operation is fully automatic.

Question 13

Ventilation

Can the temperature of the aft cargo compartment be controlled ?

Answer 13

No, aft cargo compartment heat is fully automatic.

Question 14

Ventilation

What temperature range can be selected for the FWD cargo compartment ?

Answer 14

4 to 27°C

Question 15

Ventilation

Can the BULK cargo compartment temperature be adjusted ?

Answer 15

No, its an ON / OFF situation :

• AUTO ➔ target 21°C
• Off (AUTO not visible) ➔ No heating

Question 16

Ventilation

What does the VENTILATION switch to ALTN do ?

Answer 16

It triggers the AVS (Alternate Ventilation System) :
the Forward and Aft Outflow Valves are automatically repositioned towards the ten and one o’clock positions respectively when airplane is below 13,000 ft altitude and not on ground.

Question 17

Ventilation

What is AVS (Alternate Ventilation System) ?

Answer 17

The AVS provides an alternate means of ventilating the cabin and flightdeck in the event both packs are inoperative.