This document discusses humidification and different types of humidifiers used during mechanical ventilation. It begins with objectives to describe normal airway heat and moisture exchange, the effects of dry gases, and indications for humidification. It then defines humidity and absolute versus relative humidity. The main types of humidifiers covered are bubble, passover, and heated humidifiers. Important points are made about maintaining water levels, discarding condensation, and replacing humidifiers every 24 hours to prevent bacterial growth. References are provided at the end.

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DEPARTMENT OF CHEMICAL ENGINEERING
HUMIDIFICATION
• PRESENTED BY: SAMEER ALAM
• ROLL NO : 1613351016
• BRANCH : CHEMICAL

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CONTENTS
• OBJECTIVE
• HUMIDITY
• ABSOLUTE And RELATIVE HUMIDITY
• TYPES OF HUMIDIFIERS
• IMPORTANT POINTS FOR HUMIDIFIER
• REFERENCES

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OBJECTIVE
• Describe how airway heat and moisture
exchange normally occurs.
• State the effect dry gases have on the respiratory
tract.
• State when to humidify and warm gas.
• Describe how various types of humidifiers work.
• Identify the indications, contraindications, and
hazards that pertain to humidification during
mechanical ventilation.

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HUMIDITY
• Humidity is the
quantity of moisture in
air or gas that is
caused by the
addition of water in a
gaseous state, or
vapor. Also called
molecular water or
invisible moisture. FIG 1

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ABSOLUTE And RELATIVE
HUMIDITY
1. Absolute humidity is the amount of water in a
given volume of gas; its measurement is
expressed in milligrams per liter.
2. Relative humidity is a ratio between the amount
of water in a given volume of gas and the
maximum amount it is capable of holding at that
temperature (capacity). Its measurement is
expressed as a percentage and is obtained with
a hygrometer.
3. Relative humidity= absolute humidity
capacityx100

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TYPES OF HUMIDIFIERS
• Humidifiers are either active (actively
adding heat or water or both to the device-
patient interface) or passive (Passive
humidifiers refer to typical heat and
moisture exchangers).
• Active humidifiers typically include
1. Bubble humidifiers
2. Passover humidifers
3. Heated humidifiers

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BUBBLE HUMIDIFIER
• Gas passes through
tube to bottom of
water reservoir.
• Gas bubbles through
reservoir Unheated
bubbles through
humidifier Provides
humidity for oxygen
therapy.
FIG 2

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PASSOVER HUMIDIFIERS
• Simple reservoir Gas
flows over surface of
volume of water
Usually used as
heated system to
provide humidity to
Mechanically
ventilated patients.
FIG 3

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HEATED HUMIDIFIER
• Adding heat increases
absolute humidity of gas
Heating of gas increases
risk of condensation in
tubing, causing
obstruction. Risk is
decreased by using large-
bore tubing Heated wire
circuits are used to
decrease amount of
condensation in circuit.
FIG 4

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IMPORTANT POINTS
CONCERNING
HUMIDIFIERS
1. Water levels of all humidifiers should be maintained at the levels
marked on the humidifier jar to ensure maximum humidity output.
2. Condensation occurs in the tubing of heated humidifiers. This
water should be discarded in a trash container or basin and
should never be put back into the humidifier.
3. Warm moist areas, such as heated humidifiers, are a breeding
ground for microorganisms (especially pseudomonas species). The
humidifier should be replaced every 24 hours.

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REFERENCES
• FIG 1
• FIG 2
• FIG 3
• FIG 4
• THEORY
http://www.brighthubengineering.com/hvac/41447-psychrometric-
processes-cooling-heating-and-humidification/.
https://www.vitalitymedical.com/salter-labs-humidifier-bubble-
350cc.html
https://www.cpap-supply.com/REMstar-Universal-Passover-Humidifier-
p/1006087.htm
https://www.cpapplus.com/heated-humidifiers
https://en.wikipedia.org/wiki/Humidifier

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THANK YOU