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MECHANICAL SYSTEMS TO ACCELERATE DRYING
The mechanical systems in a dryer control these same three conditions to accelerate the evaporation
of liquid water remaining in laundry. Within the dryer drum, the dryer:
A) Applies Heat to the Liquid Water
B) Provides Movement of Air over the Water
C) Increases the Surface Exposure of the Water
Efficient drying of the laundry is the result.
In a dryer, air is heated by either an electric element or a gas burner. The heated air is drawn into the
drum and passed over the laundry. To prevent the heated air from becoming completely saturated
with water vapor, a fan continually pulls the moisture-laden air from the drum and exhausts it outside.
Relatively dry heated air is continually drawn into the drum to replace the moisture-laden air being
exhausted.
(Fig. 3-4)
When you understand how a dryer works, you can understand why it is important that the dryer be
properly exhausted to the outside. If the moisture-laden air was vented back into the room where the
dryer was located, the air in the room would quickly become saturated. This same air would be continu-
ously drawn back into the dryer, heated and passed over the wet laundry. The drying time would be
greatly increased.
Fig. 3-4

TO MAINTAIN DRYING EFFICIENCY

The Dryer Must Be Correctly Installed
The Dryer Must Be Properly Vented
The Air Flow Must Be Unrestricted
(Clean Lint Screen)
The Dryer Must Not Be Overloaded
The Laundry Must Be Properly Sorted
(Heavy items dried with light weight
garments can develop over-drying and
under-drying in the same load.)
The Washer Must Extract As Much Water
As Possible During the SPIN CYCLE
Air system is similar in gas and electric dryers.
Gas Dryer shown.