<s>
A	O
Thermally	B-Device
Advantaged	I-Device
Chassis	I-Device
(	O
TAC	O
)	O
is	O
a	O
computer	O
enclosure	O
that	O
complies	O
with	O
the	O
Thermally	B-Device
Advantaged	I-Device
Chassis	I-Device
specifications	O
created	O
by	O
Intel	O
.	O
</s>
<s>
It	O
is	O
capable	O
of	O
maintaining	O
an	O
internal	O
ambient	O
temperature	O
below	O
38	O
degrees	O
Celsius	O
when	O
functioning	O
with	O
Intel	O
's	O
Pentium	B-General_Concept
4	I-General_Concept
and	O
Celeron	B-Device
D	I-Device
processors	O
based	O
on	O
90nm	O
process	O
technology	O
,	O
and	O
an	O
ambient	O
temperature	O
below	O
39	O
degrees	O
Celsius	O
when	O
using	O
a	O
Pentium	B-Device
D	I-Device
processor	O
.	O
</s>
<s>
Intel	O
maintains	O
that	O
using	O
a	O
thermally	B-Device
advantaged	I-Device
chassis	I-Device
is	O
the	O
absolute	O
minimum	O
requirement	O
for	O
using	O
Pentium	B-General_Concept
4	I-General_Concept
(	O
Prescott	O
)	O
,	O
Pentium	B-Device
D	I-Device
,	O
and	O
Celeron	B-Device
D	I-Device
,	O
processors	O
.	O
</s>
<s>
Its	O
main	O
feature	O
is	O
a	O
Chassis	B-Device
Air	I-Device
Guide	I-Device
that	O
directs	O
room	O
temperature	O
air	O
directly	O
in	O
the	O
path	O
of	O
the	O
CPU	B-Application
fan	I-Application
and	O
heat	O
sink	O
.	O
</s>
<s>
The	O
chassis	B-Device
air	I-Device
guide	I-Device
is	O
a	O
passive	O
cooling	O
system	O
,	O
and	O
relies	O
completely	O
on	O
internal	O
system	B-Application
fans	I-Application
to	O
guide	O
the	O
air	O
.	O
</s>
<s>
Airflow	O
from	O
the	O
front	O
of	O
the	O
chassis	O
moves	O
around	O
the	O
Chassis	B-Device
Air	I-Device
Guide	I-Device
,	O
allowing	O
the	O
processor	O
fan	O
to	O
only	O
draw	O
air	O
from	O
outside	O
the	O
chassis	O
,	O
providing	O
more	O
effective	O
cooling	O
.	O
</s>
