Week 06 · Thursday: Power and heat (Inside the Machine G3 to G5)

Thursday: Fans, vents and dust

A neighbor sets down a desk computer. "It sounds like a tiny jet," he says. "The fan never stops roaring." Rocket peers at the vent. Gray fluff fills the holes.

Raven points. "What do you notice about the vent? Can air even get through?"

Nova keeps her distance. "Would you like a hint? A fan pushes air. If the door is blocked, the fan just works harder."

What a fan does

A fan is a small spinning blade. It pulls cool air in through one vent and pushes warm air out another.

The fan helps carry away the heat that the processor makes.

A fan that roars all the time is a clue. Check that the air can get through.

Clue	What to do
Fan is quiet	Keep using the device
Fan gets louder	Look that the vents are clear
Fan roars all the time	Look at the vents and tell a grown-up
Fan makes a rattle or grind	Something is wrong. Tell a grown-up

LISTEN TO THE FAN

Read the question.
Tap your answer.

What does a fan do?

A fan gets louder. What is a safe first check?

The vents are full of gray fluff. Who cleans them?

Dust and blocked vents

In the story, gray fluff filled the vent holes. Fluff in a vent covers it like a blanket.

A blocked vent traps heat, so the device gets hot.

A kid may keep vents clear by using a device on a hard surface. A kid never pokes or cleans a vent.

A grown-up can clean the outside of a vent. Anything inside the case is for a repair shop.

Safety first

Never put fingers, pencils or cloths into a vent or a fan.
Cleaning liquids and cans of air are for grown-ups only.
Never open a case to reach a fan. Tell a grown-up instead.

Statement	True or false?
A fan pulls cool air in and pushes warm air out.	?
A kid may poke a pencil into a fan.	?
Dust on a vent traps heat.	?
A kid may clean a vent with a wet cloth.	?

WHY THIS EXERCISEFans and vents keep a device cool only when air can flow. Kids keep vents uncovered, and grown-ups do the cleaning.

What opening lets air flow in and out of a device?

WHY THIS EXERCISEVents are the doors for air. If they are covered or dusty, heat stays trapped inside.

PUT THE ROARING FAN CASE IN ORDER

?Ask a grown-up to clean the outside of the vents
?Look at the vents without touching them
?Name it: the vents are blocked with dust
?Test: is the fan quieter now?
?Notice the fan roars all the time

WHY THIS EXERCISEThe crew method finds the cause. The cleaning itself belongs to a grown-up.

Try it

Hold a sheet of paper in front of your mouth and blow gently.
Now hold a thick book there and blow. Does any air get through?
Dust on a vent works like the book.

The spinning blade that moves air is the

Air goes in and out through a

Gray fluff that blocks vents is

Cleaning a vent is a job for a

Listen to a device at home for one minute, with a grown-up. Write what you hear and what you think the fan is doing.

Excellent detective work! You can read a fan like a clue. Tomorrow you will put the power and heat story together.