building construction and drawing

1. BCD
UNIT V
UNIT-V
Prof
P f S S JAHAGIRDAR
BE (CIVIL), ME(ENV.),PhD(persuing)
NK Orchid college of Engg and Tech , Solapur
Engg. Tech.

2. Process of treating the air so as to
control simultaneously its
temperature, humidity, purity
and distribution to meet the
requirements of controlled space.

3. 1) Comfort and health of
occupants
p
2) Needs of certain industrial
processes
3) Efficient working of
commercial premises/offices
p /

4. Comfort air conditioning : - Aim at
giving max human comfort to
occupants/users of conditioned
space
Industrial air conditioning : - The
coditioning creates, controls and
maintains such an environment
inside the conditioned space, that it
would suit b t t th needs of
ld it best to the d f
industry.

5. )
1) Summer air conditioning g
In summer outside temp is more and
hence cooling of air is required
Consists of
i) Air cleaning
ii)
) Air cooling
iii) Dehumidification
iv) Air distribution/circulation

7. 2) Winter air conditioning
In winter outside temperature is low
hence h i of air i needed f
h heating f i is d d for
comfort.
Cycle of operations consists of
i)
) Air cleaning
ii) Air heatingg
iii) Humidification
iv) Air di t ib ti / i l ti
Ai distribution/circulation

9. 1) Temperature control
Effective temp = 200C to 230C in
summer
Effective Temp = 180C to 220C in
winter
For Indian conditions 250C with 60%
relative humidity to 300C with 45 %
relative h idit with air velocity not
l ti humidity, ith i l it t
exceeding 10 m/min

10. During summer dehumidification
is done so that relative humidity
y
is 40 to 50%
During winter h humidification is
df
done so that relative humidity is
50 to 60 %

11. High velocity of conditioned
air may y cause g
greater
temperature difference
between outside and inside
inside.
Velocity = 6 to 9 m/sec is
desirable

12. Air should be free from
odour, toxic gases, bacteria
and other micro-organisms

13. 1. Filtration
2. Heating (in winter)
3. Cooling (in summer)
4. Humidification
5. Dehumidification
6.
6 Air circulation or distribution

14. Should be capable of removing dust, ash,
smoke,
smoke bacteria etc
Should be capable of holding moderate
amount of d
f dust without affecting the
h ff h
efficiency
Should offer low resistance to flow of air
Workable under sufficient range of
velocities.
Should ff d
Sh ld afford easy cleaning manually or
l i ll
mechanically

15. Heating is necessary in winter so
as to compensate heat loss from
room.
Pre heating of incoming air may be
done by passing over air furnaces
or coils through which hot water is
circulated.

16. Cooling of incoming air is
necessary in summer.
y
Principle of mechanical
refrigeration is used.
f d

17. Humidification or addition of
water is necessary in winter
when air because of low temp
has less humidity.
Incoming air is passed through
pans of water or wet cloth strips

18. In this process certain amount of
water is extracted from air.
This is done in summer where
incoming air is cooled
cooled.
Adsorbents can be used to
adsorb excess moisture from air