The document discusses the principles of evaporative cooling, which has been used for thousands of years to lower temperatures. Evaporative cooling works by using the natural process of evaporation to remove heat from the air. As water evaporates, it absorbs heat and causes the surrounding air temperature to decrease. More recently, the physics behind evaporation and heat transfer have been studied scientifically. Evaporative cooling can provide an energy-efficient alternative to mechanical cooling systems in many applications.

1. EinB2016
–
5th
Interna1onal
Conference
“ENERGY
in
BUILDINGS
2016”
Luigi
Nalini,
Speaker
luigi.nalini@carel.com
Energy
saving
through
evapora7ng
cooling
in
comfort
and
industrial
applica7ons

2. EinB2016
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5th
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“ENERGY
in
BUILDINGS
2016”
Everybody
has
certainly
experienced
the
cooling
effect
caused
by
a
current
of
air
on
the
swea1ng
skin
or
on
wet
clothes,
as
well
as
the
perceived
lower
temperature
in
the
vicinity
of
waterfalls
where
microscopic
water
droplets
are
suspended
in
the
air.
Based
on
empirical
observa1ons,
even
without
knowing
its
basic
physical
principle,
humankind
has
Evapora7ve
cooling
has
been
used
by
humankind
since
50
centuries
ago!
used
since
from
the
third
millennium
B.C.
the
evapora1ve
cooling
to
mi1gate
the
temperature
of
spaces,
par1cularly
in
areas
with
a
hot
and
dry
climate.
Only
over
the
last
two
centuries,
scien1sts
have
studied
the
basics
of
thermodynamics
and
processes
related
to
the
exchange
of
sensible
and
latent
heat
and
found
the
theore1cal
principles
of
cooling
by
evapora1on
which,
however,
has
played
a
marginal
role
in
the
recent
past
due
to
the
extensive
use
of
mechanical
refrigera1on
systems.

3. EinB2016
–
5th
Interna1onal
Conference
“ENERGY
in
BUILDINGS
2016”
According
to
the
molecular
kine1c
theory,
as
any
element
water
assumes
the
solid,
liquid,
gaseous
state
in
func1on
of
the
internal
energy
of
molecules,
that
occurs
as
vibra1onal,
rota1onal,
transla1onal
mo1on
and
reciprocal
collisions.
Temperature
is
a
measure
of
the
average
internal
energy
and
therefore
the
higher
the
temperature,
the
greater
the
internal
energy
of
the
molecules.
Upon
an
energy
input,
liquid
water
molecules
increase
their
internal
energy.
Part
of
them
reaches
an
energy
level
sufficient
to
enter
in
the
evapora7on
process,
overcoming
the
aWrac1ve
forces
of
the
bulk
of
the
liquid,
passing
to
the
gaseous
state
(vapor)
and
spreading
in
the
available
space
around.
The
Water
Evapora7on
Process

4. EinB2016
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2016”
0
5
10
15
20
25
30
35
40
45
50
14000
12000
10000
8000
6000
4000
2000
0
temperature
-­‐
°C
Vapor
pressure
-­‐
Pa
SATURATION
PRESSURE
VPS
OF
WATER
vs
TEMPERATURE
The
diagram
shows
the
pressure
exerted
by
the
water
vapor
molecules
vs
temperature
just
above
the
surface
of
liquid
water.
In
this
condi1ons
water
vapor
is
in
equilibrium
with
its
condensed
state
and
therefore
that
pressure
is
said
Satura7on
Pressure
PVS.
Leaving
the
liquid
water
and
entering
into
the
atmosphere
the
vapor
molecules
must
«compete»
with
the
pressure
exerted
by
the
other
gases.
The
vapor
molecules,
due
to
their
kine1c
energy,
exert
over
the
con1guous
bodies
a
macroscopic
pressure
propor1onal
to
the
number
and
to
the
force
of
the
collisions.
As
well
as
the
internal
energy,
also
vapor
pressure
depends
on
temperature.
Water
Vapor
Pressure

5. EinB2016
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“ENERGY
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2016”
The
atmosphere,
a
mixture
of
dry
air
(i.e.:
permanent
gases
-­‐
such
as
N2,
O2,
Ar
-­‐
without
vapor)
and
vapor,
has
a
pressure
PATM
(around
1,033
bar
at
sea
level)
that
is
equal
to
the
sum
of
the
the
individual
pressure
of
the
several
gaseous
components.
According
to
the
gas
laws,
the
individual
pressure
of
any
gas
(called
also
par7al
pressure)
in
the
mixture
is
propor7onal
to
THE
ATMOSPHERE
IS
A
MIXTURE
OF
GASES
OVERALL
PRESSURE
=
101.325
Pa
@
SEA
LEVEL
NITROGEN
OXYGEN
ARGON
WATER
VAPOR
Of
course
the
maximum
quan1ty
is
got
when
the
vapor
par1al
pressure
equals
the
satura1on
pressure
PVS
;
in
this
condi1on,
the
air
is
said
Saturated.
However,
differently
from
permanent
gases
(whose
rela1ve
percentage
is
stable)
water
vapor
concentra7on
varies
with
1me,
loca1on
and
weather.
its
volumetric
frac7on;
therefore
the
number
of
molecules
of
water
contained
in
the
air
is
propor1onal
to
the
vapor
par1al
pressure.
Vapor
in
the
Atmosphere

6. EinB2016
–
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“ENERGY
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2016”
The
ra1o
between
the
actual
pressure
PV
and
the
satura1on
pressure
PVS
at
the
same
temperature
is
defined
rela7ve
humidity
RH:
RH
=
PV
/
PVS
[%]
(1)
The
Vapour
Pressure
Deficit,
or
VPD,
is
the
difference
between
the
actual
water
vapor
pressure
and
the
satura1on
pressure:
it
indicates
the
maximum
capability
by
the
air
to
absorb
addi1onal
vapor
at
that
temperature.
The
formula
closely
appoxima1ng
the
VAPOR
PRESSURE
OF
WATER
vs
TEMPERATURE
AND
RH
0
1000
2000
3000
4000
5000
6000
0
5
10
15
20
25
30
35
40
temperature
-­‐
°C
Vapor
pressure
-­‐
Pa
10%
25
PVS
=
3170
PV
=
1270
VAPOR
PRESSURE
DEFICIT
ATMOSPHERIC
PRESSURE
(101,325
Pa)
When
the
content
of
vapor
in
the
atmosphere
is
not
enough
for
satura7on,
also
the
vapor
pressure
PV
is
lower
than
the
saturated
pressure
PVS.
saturated
vapor
pressure
Pvs
vs.
temperature
T
[°C]
between
0°C
and
80°C
is:
PVS
=
exp
(23,5771
-­‐
4042,9/(235,57
+
T))
[Pa]
(2)
Psychrometric
Expressions
1/2

7. EinB2016
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5th
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“ENERGY
in
BUILDINGS
2016”
The
vapor
content
in
the
atmosphere
is
called
absolute
humidity
x,
expressed
as
mass
of
water
vapor
per
unit
mass
of
dry
air;
it
can
be
calculated
knowing
the
par1al
pressure
Pv
-­‐
func1on
of
temperature
-­‐
and
rela1ve
humidity:
x
=
0,622
*
PV/(PATM
–
PV)
[kgv/kga]
(3)
The
expression
(3)
shows
that,
at
a
certain
atmospheric
pressure,
absolute
humidity
x
is
func7on
exclusively
of
the
vapor
pressure
PV.
Another
important
parameter
of
humid
air
is
the
enthalpy
H,
i.e.
its
energy
thermal
content,
made
of
the
heat
contained
in
dry
air
and
the
internal
energy
of
vapor
molecules,
that
depends
on
temperature
and
on
absolute
humidity:
H
=
cpa
*
T
+
x
*
(r0
+
cpv
*
T)
=
1,005
*
T
+
x
*
(2501
+
1,9
*
T)
[kJ/kga]
(4)
where:
• T
[°C]
=
temperature;
• cpa,
cpv
[kJ/kg°C]=
specific
heat
of
dry
air
and
of
water
vapor;
• r0
[kJ/kg]
=
latent
heat
of
water
at
0°C.
The
expressions
from
(1)
to
(4)
are
the
bases
of
psychrometric
chart,
i.e.
the
graph
of
the
thermodynamic
parameters
of
moist
air
at
a
constant
pressure.
Psychrometric
Expressions
2/2

8. EinB2016
–
5th
Interna1onal
Conference
“ENERGY
in
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2016”
Water
liquid
molecules
require
an
heat
input
to
increase
their
internal
energy
in
order
to
pass
to
vapor.
This
heat
can
be
given
by
an
external
source
(i.e.:
by
the
sun,
by
electricity
or
by
burning
a
fuel)
as
it
happens
normally
during
winter
humidifica1on.
Alterna1vely,
the
evapora1on
heat
can
be
supplied
by
the
air
itself
with
no
external
input:
the
molecules
that
evaporate
absorb
heat
from
the
en1re
air-­‐
liquid-­‐vapor
system
which
then
undergoes
a
temperature
decrease.
This
process
is
therefore
defined
adiaba7c
(i.e.
without
transfer
of
heat)
and
isenthalpic
because
the
heat
content
of
air
being
humidified
does
not
change.
Just
for
the
same
reason
this
process
is
defined
adiaba7c
cooling.
In
an
adiaba1c
cooler
an
air
stream
is
circulated
over
an
extended
water
surface
with
which
it
comes
into
close
contact.
Within
the
cooler
the
air
flow
causes
the
evapora1on
of
water.
Adiaba7c
Cooling
1/2
water
adiaba1c
cooler
ADIABATIC
COOLER
SCHEME
cooled
humid
air
@
temp.
T2
<
T1
entering
warm
air
@
temp.
T1

9. EinB2016
–
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Interna1onal
Conference
“ENERGY
in
BUILDINGS
2016”
Isothermal
Humidifica1on
Adiaba1c
humidifica1on
Air
Hea1ng
Air
Cooling
Temperature
Enthalpy
Absolute
Humidity
Rela1ve
Humidity
0
5
10
15
20
25
30
0
5
10
15
20
25
30
35
40
30
15
10
5
0
25
20
20
100
70
80
90
60
30
40
50
DRY
BULB
TEMPERATURE
-­‐
°C
ABSOLUTE
HUMIDITY
–
g/kg
PATM
=
101.325
Pa
10%
Process
Trend
Psychrometric
Chart
and
Basic
Processes
ISENTHALPIC
LINES

10. EinB2016
–
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Conference
“ENERGY
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BUILDINGS
2016”
Due
to
the
difference
between
the
vapor
pressure
over
the
water
surface
and
the
par1al
vapor
pressure
of
unsaturated
air,
the
evapora1on
of
water
will
take
place.
The
lowest
temperature
theore1cally
aWainable
corresponds
to
the
intersec1on
between
the
isoenthalpic
line,
followed
along
the
process,
and
the
satura1on
curve:
this
is
represented
by
the
black
arrow
in
the
graphic.
Along
the
process
un1l
the
satura1on:
• the
Vapor
Pressure
Deficit
decreases
down
to
zero;
• the
rela1ve
humidity
arrives
to
100%;
• the
cooling
effect,
due
to
evapora1on,
reaches
the
maximum
value.
RH
[%]
100%
60%
40%
80%
20%
PVS
–
PV
[Pa]
4
2
6
0
Qsp
[J/kg
of
air]
10
5
15
0
20
saturation
Vapor
pressure
deficit
Air
rela7ve
humidity
Cooling
effect
ON
GOING
EVAPORATIVE
COOLING
PROCESS
20,6
25
30
35
40
15
10
5
0
Vapor
par7al
pressure
-­‐
kPa
absolute
humidity
–
gv/kga
38
1
2
0
0,5
2,5
1,5
water
evapora1ve
cooler
38°C
20%
RH
20,6
°C
100%
RH
Adiaba7c
Cooling
2/2

11. EinB2016
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“ENERGY
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2016”
However,
along
the
process,
the
temperature
and
the
vapor
pressure
differen1als
between
humid
air
and
water
sharply
decrease,
making
the
satura1on
of
leaving
air
hardly
achievable
in
prac1ce.
The
capacity
of
an
evapora1ve
cooler
to
approach
the
satura1on,
defined
as
Satura7on
Effec7veness
μe,
is:
μe
=
(T1
–
T2)/(T1
–
TWB)
[%]
DIRECT
SATURATION
EFFECTIVENESS
Dry
bulb
temp.
-­‐
°C
T1
T2
TWB
The
evapora1on
of
water
involves
a
simultaneous
transfer
of
heat
and
mass
(evapora1ng
molecules)
between
the
air
stream
and
the
liquid
surface.
• The
heat
exchange
is
propor1onal
to
the
temperature
difference.
• The
mass
exchange
(evapora1ng
water)
is
propor1onal
to
the
vapor
pressure
difference.
• Their
rate
depend
linearly
on
the
interface
area
between
water
and
air.
In
direct
evapora1ve
coolers
μe
ranges
between
20-­‐30%
(typical
of
the
tabletop
equipment)
up
to
90%
and
more
for
large
high
performance
ducted
Direct
Satura7on
Effec7veness

12. EinB2016
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“ENERGY
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2016”
The
adiaba1c
evapora1on
process
is
very
efficient
because,
where
prac1cable,
produces
a
cooling
effect
with
no
energy
consump7on.
An
evapora1ve
cooler
designed
for
air
condi1oning
purposes
reduces
the
processed
air
temperature
but
increases
its
humidity
content;
this
should
be
considered
in
order
to
keep
the
hygrothermal
room
condi1ons
within
the
limits
required
for
each
applica1on.
Therefore
room
air
condi1oning
by
means
of
an
evapora1ve
cooler
is
not
viable
just
recircula7ng
internal
air
because
the
indoor
humidity
would
soon
approach
the
satura1on
condi1on.
Instead,
it
requires
the
introduc7on
of
outside
air
to
which
obviously
must
correspond
an
equal
rate
of
exhaust
air.
Evapora1ve
cooling
equipment
can
be
direct
or
indirect.
40%
RH
80%
RH
100%
RH
100%
RH
YES
NO
Adiaba7c
Cooling
Requires
Air
Changes

13. EinB2016
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“ENERGY
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2016”
GI
Total
air
flow
rate
Gvent
Min
fresh
air
flow
EC
Evapora1ve
cooler
CC
Cooling
coil
GO
Outside
air
flow
CD
Combined
dampers
PC
Pre-­‐hea1ng
coil
RC
Re-­‐hea1ng
coil
The
free
cooling
by
Direct
Evapora7ve
Cooling
(DEC)
is
got
cooling
(and
humidifying)
outdoor
air
and
introducing
it
straight
into
the
space:
this
is
therefore
viable
whenever
the
temperature
T2
of
the
outdoor
air
downstream
the
adiaba1c
cooler
is
lower
than
the
indoor
temperature
Tamb.
In
fact,
for
the
same
air
flow,
the
cooling
capacity
is
propor1onal
to
the
air
flow
rate
and
to
the
difference
(T2-­‐Tamb).
GI
GO
GI
CD
PC
EC
CC
RC
AHU
UNIT
WITH
DIRECT
ADIABATIC
COOLER
AND
MOTORIZED
DAMPERS
TO
ADJUST
THE
AIR
FLOW
RATES
T2Tamb
Direct
Evapora7ve
Cooling
from
the
space
to
the
space
from
outdoor
to
outdoor

14. EinB2016
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“ENERGY
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2016”
GI
Total
air
flow
rate
Gvent
Min
fresh
air
flow
EC
Evapora1ve
cooler
HU
Humidifier
GO
Outside
air
flow
α
Ra1o
GO/GE
HE
Heat
exchanger
CC
Cooling
coil
GE
External
air
flow
CD
Combined
dampers
PC
Pre-­‐hea1ng
coil
RC
Re-­‐hea1ng
coil
GO
(=
r
*
GE);
TO;
HO
GE;
TE;
HE
GI
CD
PC
HU
CC
RC
GI-­‐GE
HE
GI
≥
GE
≥
Gvent
AC
GO
;
TC;
HA
GE
;
TX;
HX
GO
;
TA;
HA
GI
AHU
UNIT
WITH
INDIRECT
ADIABATIC
COOLER
AND
MOTORIZED
DAMPERS
TO
ADJUST
THE
AIR
FLOW
RATES
The
Indirect
Evapora7ve
Cooling
(IEC)
occurs
by
cooling
air
in
an
adiaba1c
humidifica1on
process,
and
then
in
turn
using
the
same
air
to
reduce
–
via
a
heat
exchanger
–
the
temperature
of
a
second
stream
of
air,
whose
moisture
content
remains
unchanged.
Indirect
Evapora7ve
Cooling

15. EinB2016
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“ENERGY
in
BUILDINGS
2016”
Based
on
a
mass
transfer
process,
an
adiaba1c
cooler
should
have:
• enough
air
velocity
to
create
a
sufficient
turbulence
and
the
removal
of
vapor
molecules
from
the
water
surface;
• enough
interface
surface
between
cooled
air
and
evapora1ng
water.
There
are
two
basic
ways
to
expand
the
surface:
1) by
using
a
solid
wet
media
with
an
extended
surface
that,
if
kept
wet,
act
as
a
vast
water-­‐air
interface
area;
2) by
introducing
into
the
air
stream
water
in
the
form
of
minute
droplets
using
a
process
known
as
nebulisa7on,
pulverisa7on
or
atomisa7on.
Features
of
Most
Used
Adiaba7c
Coolers

16. EinB2016
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In
these
adiaba1c
humidifiers
the
air
is
passed
through
weWed
pads,
i.e.:
honeycomb
structures
of
resin-­‐
impregnated
cellulose
or
glass
fiber
offering
a
wide
interface
area.
The
pads,
placed
ver1cally,
are
kept
wet
by
a
water
flow
distributed
on
their
upper
edge.
Wet
Media
Humidifiers
1/2
In
ducted
HVAC
systems
wet
media
humidifiers
are
generally
placed
inside
of
air
handling
units;
the
wet
pad
is
made
using
modules.
This
makes
possible
to
adapt
the
front
surface
and
the
depth
of
the
wet
media
according
to
the
available
space,
the
air
flow
rate,
the
efficiency,
the
allowed
pressure
loss.

17. EinB2016
–
5th
Interna1onal
Conference
“ENERGY
in
BUILDINGS
2016”
Only
part
of
the
water
drawn
from
a
boWom
tank
by
a
recircula1on
pump
and
distributed
onto
the
pads
evaporates
when
the
rest
is
recirculated.
The
evapora1on
process
increases
the
concentra1on
of
salts
which
may
build
up
on
the
surface,
forcing
to
clean
or
replace
the
pads
when
clogged.
Furthermore
they
should
be
periodically
controlled
because
the
presence
of
a
warm
water
recircula7on
poten7ally
promotes
a
risky
bacterial
growth.
Last
but
not
least,
the
air
side
pressure
drop
of
the
pads
requires
an
addi7onal
energy
consump7on
even
when
no
humidifica7on
is
needed.
Their
use,
widespread
for
the
limited
price,
should
be
carefully
evaluated
looking
also
at
the
opera1ng
costs,
some1mes
surprisingly
high.
Wet
Media
Humidifiers
2/2

18. EinB2016
–
5th
Interna1onal
Conference
“ENERGY
in
BUILDINGS
2016”
These
devices
are
equipped
with
a
volumetric
pump
which
pressurizes
the
water
to
values
between
70
and
100
bar
and
delivers
it
to
small
nozzles
that
produce
a
fine
mist
(droplets
of
10-­‐15
micron)
easily
absorbed
by
air
stream
because
the
surface
offered
by
1
liter
of
water
atomized
at
15
μm
is
as
high
as
400
m2.
PUMPING
STATION
ATOMIZING
NOZZLE
High
Pressure
Atomising
Systems
1/2
The
distribu1on
piping
network
that
supports
and
supplies
the
nozzles
is
posi1oned
in
an
air
duct
or
placed
directly
into
the
environment
to
humidify.
NOZZLE
RACK
SUSPENDED
TYPE
NOZZLE
RACK
IN
AHU
SECTION

19. EinB2016
–
5th
Interna1onal
Conference
“ENERGY
in
BUILDINGS
2016”
High
pressure
atomising
systems
may
reach
an
excellent
level
of
accuracy
(±
2%)
of
the
humidity
in
the
controlled
space
and
very
high
capaci1es
with
a
negligible
electric
consump1on
absorbed
by
the
pump
(<4
W
per
liter
of
sprayed
water).
Under
the
hygienic
aspect
they
are
not
cri1cal
because
do
not
promote
bacterial
growth;
infact:
§ in
the
case
of
direct
atomiza1on
into
the
environment,
the
sprayed
water
is
fully
absorbed
by
the
air;
§ in
ducted
systems
the
frac1on
not
evaporated
-­‐
usually
very
small
-­‐
is
drained
without
recircula1on.
The
use
of
demineralised
or
sweetened
water
is
recommended
to
prevent
clogging
of
the
nozzles.
High
pressure
atomising
systems
are
available
for
capacity
up
to
many
thousands
of
kg/h.
High
Pressure
Atomising
Systems
2/2

20. EinB2016
–
5th
Interna1onal
Conference
“ENERGY
in
BUILDINGS
2016”
Ultrasonic
Humidifiers
STAND
ALONE
UNIT
SMALL
SIZE
UNIT
DUCTED
TYPE
UNIT
Ultrasonic
humidifiers
provide
an
extra
fine
atomiza1on
of
water
(≈
3
μm)
by
means
of
the
high-­‐
frequency
vibra1on
(close
to
1,7
Mhz)
of
a
piezoelectric
element
(or
more
than
one,
in
parallel);
the
absorp1on
of
vapor
is
immediate
due
to
the
wide
interface
surface
(2000
m2
offered
by
1
liter
of
water
atomized
at
3
μm).
Due
to
size
and
cost
they
are
convenient
for
small
and
medium
installa1ons
(0,5
to
15
kg/h).
The
use
of
demineralised
water
is
highly
recommended.
Best
ultrasonic
humidifiers
reach
excep1onal
levels
of
precision
(±
1%)
in
the
en1re
range
of
their
rated
capacity
and,
thanks
to
the
high
efficiency
of
absorp1on,
they
are
suitable
for
the
distribu1on
of
the
produced
mist
directly
into
the
room
as
well
as
in
ducted
systems.

21. EinB2016
–
5th
Interna1onal
Conference
“ENERGY
in
BUILDINGS
2016”
To
Conclude,
let
Us
Men7on
a
Few
Case
Studies

22. EinB2016
–
5th
Interna1onal
Conference
“ENERGY
in
BUILDINGS
2016”
Evapora7ve
Cooling:
Datacenter
Applica7on
The
need:
humidity
control
and
evapora1ve
cooling
A
company
has
a
big
data
center
in
Middlesbrough
(Newcastle-­‐
UK).
It
has
more
than
180
global
data
centers
and
IT
service
companies.
Data
hall
Atomizing
nozzles
Hot
exhaust
air
to
data
centre
Coniugated
dampers

23. EinB2016
–
5th
Interna1onal
Conference
“ENERGY
in
BUILDINGS
2016”
Internal
Views

24. EinB2016
–
5th
Interna1onal
Conference
“ENERGY
in
BUILDINGS
2016”
Evapora7ve
Cooling:
Air
Cooled
Heat
Exchangers
In
aircooled
heat
exchangers
(i.e.:
condensers,
radiators,
etc.)
the
intake
air
is
adiaba1cally
cooled
to
improve
the
performance
in
hoWest
periods.
Water
may
be
sprayed
in
excess
in
order
to
wet
the
finned
coil
so
promo1ng
a
further
evapora1on
during
air
hea1ng
along
the
exchanger.

25. EinB2016
–
5th
Interna1onal
Conference
“ENERGY
in
BUILDINGS
2016”
COMPARATIVA ESTACIONES 4/09/06
0,00
10,00
20,00
30,00
40,00
50,00
60,00
70,00
80,00
90,00
12.30
13.00
13.30
14.00
14.30
15.00
15.30
16.00
16.30
17.00
17.30
18.00
18.30
19.00
19.30
20.00
20.30
21.00
21.30
22.00
22.30
23.00
23.30
HORA
ºCY%HR
Tª EXT. PEÑAG. Tª EXT. ILUST. Tª AMB. PEÑAG. Tª AMB. ILUST. Tª IMP. PEÑAG. Tª IMP. ILUST.
HR EXT. PEÑAG. HR EXT. ILUST. HR AMB. PEÑAG. HR. AMB. ILUST. HR IMP. PEÑAG. HR IMP. ILUST.
El ecpa S.L.
Instalaciones y Control
The
aim
of
this
solu1on
is
to
provide
more
comfort,
cooling
the
environment
using
water
as
a
“source
of
power”,
because
it’s
considerably
more
economic
than
tradi1onal
cooling
systems
(direct
expansion)
as
it
consumes
less
power.
Evapora7ve
Cooling:
Subway
Applica7on
Number
of
pla•orms:
2
Q
=
90,000
m3/h
for
each
pla•orm
(ven1la1on)
Outdoor
air
=
100%
Discharging
air
condi1ons:
27-­‐28°C/70-­‐80%
r.H.
Result:
In
the
period
15/july/2006
to
15
sept/2006,
the
temperature
in
this
sta1on
was
3.4°C
colder
than
in
other
comparable
sta1ons.
Peñagrande
subway
sta1on,
Madrid

26. EinB2016
–
5th
Interna1onal
Conference
“ENERGY
in
BUILDINGS
2016”
Need:
efficiency
improvement
of
a
new
gas
turbine
for
produc1on
of
electricity
Petrochemical
complex
With
23
plants,
they
operate
400,000
barrels
per
day
of
crude
oil,
produce
18.4
million
tons
per
annum
(mpta)
of
petroleum-­‐based
products
and
2.4
mpta
of
ethylene
and
propylene-­‐based
deriva1ves
Evapora7ve
Cooling:
Industrial
Applica7on
Technical
note:
Cooling
the
combus1on
air
ingested
by
the
turbine
–
even
by
a
few
degrees
–
can
increase
power
output
substan1ally.
This
because
cooled
air
is
denser
and
therefore
gives
the
turbine
a
higher
mass-­‐flow
rate
and
pressure
ra1o,
resul1ng
in
increased
turbine
output
and
efficiency
–
as
much
as
1
%
per
degree
Celsius.
Varia1on
of
the
performance
of
a
gas
turbine
vs.
air
intake
temperature

27. EinB2016
–
5th
Interna1onal
Conference
“ENERGY
in
BUILDINGS
2016”
The
solu7on
Project
condi7ons:
Airflow
:
80.000
m3/h
From
43°C
and
20%
R.H.
Desired
25
°C
with
max
85%
R.H.
Total
Rack
Capacity
:
690
l/h
Turbine
Evapora7ve
Cooling
Diagram

28. EinB2016
–
5th
Interna1onal
Conference
“ENERGY
in
BUILDINGS
2016”
Humidifica7on
in
a
Music
Hall
in
Athens
The
needs
1)
Control
humidity
level
during
all
seasons,
ie..
instruments
made
of
wood
are
the
most
affected
and
come
into
contact
with
non-­‐wood
pieces,
string
instruments
(guitars,
violins,
etc.).
2)
Changes
in
humidity
cause
the
detune
problems
to
singers,
during
a
performance.
Room
environment
must
be
at
show1me
condi1ons
before
musicians
being
warming
up.
The
solu7ons
Music
hall:
4
–
adiaba1c
mul1zone
Master
sta1on
10
–
adiaba1c
mul1zone
Slave
sta1on
14
–
distribu1or
rack
14
–
drop
separators
Library:
2
–
adiaba1c
mul1zone
Master
sta1on
6
–
adiaba1c
mul1zone
Slave
sta1on
8
–
distribu1or
rack
8
–
drop
separators
Greek
Na1onal
Opera,
Athens

29. EinB2016
–
5th
Interna1onal
Conference
“ENERGY
in
BUILDINGS
2016”
CAR
FACTORY
Humidifica1on
in
most
automo1ve
paint
booths
has
tradi1onally
been
accomplished
by
water
spray
coils
or
wet-­‐media
located
in
the
air
houses
serving
the
paint
booths.
The
needs
Desired
stable
paint
booth
condi1ons
at
65
to
75°F
&
65
to
75%rH.
The
pain1ng
booths
are
supplied
with
permanently
condi1oned
air
by
a
ducted
system.
Humidifica7on
in
Water-­‐Borne
Pain7ng
Booths
The
results:
the
system
has
operated
with
a
precision
previously
unknown
in
this
industry,
achieving
set
point
in
10
minutes
from
cold
startup.
From
the
actual
performance
graph,
from
a
cold
start,
the
system
comes
into
specifica1on
within
10
minutes
and
then
maintains
±1°F
and
±2%rH.
The
old,
simple
cardboard
pads
will
no
longer
provide
the
precision
and
reliability
demanded.

30. EinB2016
–
5th
Interna1onal
Conference
“ENERGY
in
BUILDINGS
2016”
Humidifica7on
in
a
Museum
in
Venice
The
need
Temperature
and
Humidity
control
inside
the
various
rooms
with
1ght
Temperature
and
Humidity
set
point
range
(24°C
Temperature
–
50%
rH
with
±
5%
tolerance).
The
installed
system
It
was
chosen
a
Direct
Expansion
Units
(Mul1func1on
air/water
cooled
units
for
climate
control
+
Fan
Coils)
with
its
regula1on
system
for
temperature
control,
temperature
and
Humidity
values
recording
and
remote
management
via
Internet
access.
Due
to
historical
architecture
of
the
building,
it
was
not
allowed
the
installa1on
of
water
piping
for
hydronic
systems.
Technical
Solu7on:
Air/Water
Units
–
Fan
Coils
–
Ultrasonic
Humidifiers
AG150A
fan-coil
Bus
M-Net
fan-coil
gatew
ay
Ethernet
(cross
cable)
fan-coil
BUS
SUPERVISION
BUSpLAN
BUS
GATEWAY
BUS HUMIDIFIERS
RS485 bus GATEWAY
RS485 bus pLAN
RS485 bus HUMIDIFIERS
RS485 bus SUPERVISION
Results
• Reduced
energy
requirements:
60W
per
litre
of
spray
per
hour,
corresponding
to
about
7%
of
the
energy
consump1on
of
a
tradi1onal
humidifier.
• Use
of
demineralized
water
eliminates
the
problem
of
bacteria
improving
the
air
quality.
• The
adiaba7c
humidifica7on
process
decreases
the
temperature
of
the
air
in
summer7me,
thus
reducing
the
ac7vity
of
the
compressors
and
saving
energy.
• Extremely
fine
droplet
spray:
the
water
is
finely
sprayed
into
extremely
small
droplets
(few
microns)
easily
and
quickly
absorbed
by
the
air.

31. EinB2016
–
5th
Interna1onal
Conference
“ENERGY
in
BUILDINGS
2016”
Luigi
Nalini,
Speaker
luigi.nalini@carel.com