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Are
there any special
requirements
for the use
of Portable
Air Conditioning? |
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Yes.
Access to either
an opening window,
external door or
suspended ceiling
is essential in order
that the hot air
exhaust can be ducted
out by either a flexible
hose (tumble dryer
type) or a condenser
box. The hose is
supplied in specific
lengths so don't
forget to ask for
any extension hosing
if required. |
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My
shop or office
doesn't have
windows or
a suspended
ceiling. Does
this mean I
cannot have
a portable
air conditioner? |
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In
all likelihood we
will be able to help
you with our range
of Evaporative Coolers.
These units do not
use exhaust hoses
and are ideal for
shops where the front
and/ or rear doors
can be kept open
and other large ventilated
areas such as factories
and warehouses etc.
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Do
Portable Air
Conditioners
require installation? |
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The
'hose exhaust' type
of air conditioner,
(the vast majority)
do not need any special
installation other
than placing the
exhaust hose out
of the window - just
switch on! If you
are ducting to a
suspended ceiling
void then simply
push the hose into
the void. Some of
our more powerful
portable air conditioners
comprise an internal
unit, connected by
a 3 to 35 metre hose
to a condenser box
which either sits
on a window ledge
or is hung out of
a window (fittings
supplied with unit)
or sits on any flat
outside surface.
This may require
a little help from
your handy person! |
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Do
Portable Air
Conditioners
need to be
filled with
water? |
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Ours
don't! - But many
of the Air Conditioning
units supplied by
hire companies do
require frequent
filling with water
(2/3 times daily)
which office staff
generally find a
'pain'. |
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How
do I calculate
my Portable Air
Conditioning
requirements? |
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Simple! -
grab a calculator
and follow the simple
instructions or have
even more fun and
click on our all
singing and dancing
CoolCulator Wizard
a) Multiply
the length by the width by
the height of the room to be
air-conditioned which will
give you the cubic capacity;
b) If
you are measuring in feet then
multiply the cubic capacity
by 5 which will determine your
Btu requirements. If you are
young at heart or just younger
than us old fogies and your
measuring in metres, then simply
multiply the cubic metres by
175.
Example: Room
dimensions are 25ft x 12ft
x 8ft = 2,400 cubic feet. Multiply
by 5 giving 12,000 Btu's
Example: Room
dimensions 7.6 metres by 3.7
metres by 2.5 metres = 70.3
cubic metres. Multiply by 175
giving 11,810 Btu's.
The above calculations
assume an office of
2 people and 2 computer
screens. For every
additional person and/
or computer screen
add 500 Btu's. If you
have large south(ish)
facing windows or a
skylight then multiply
the total Btu requirement
by 1.5. If you are
in any doubt about
your calculations,
our sales staff will
be delighted to help
you.
After
you've worked out your Btu
requirements, please refer
to our hire tariff and get
on the blower to us (pun intended!). |
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How
effective is
Portable Air
Conditioning? |
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Air
conditioning isn't
just a matter of
lowering the air
temperature; it is
about making the
living environment
more comfortable
and offering a cool
haven to those coming
from outside. In
order to achieve
this, it is sufficient
for the temperature
to be 3-6 C lower
than outside; a lower
temperature than
this would actually
feel cold and unpleasant.
The air conditioner
doesn't just cool,
it also dries the air
by reducing the amount
of humidity in it;
it is in fact the level
of humidity in the
air which causes the
sensation of unbearable
heat felt on the hottest
summer days. In order
to maximise the appliance's
performance, it is
advisable to keep the
doors and windows closed
and to begin the air
conditioning process
before the heat from
outside has had a chance
to affect the walls,
furniture and other
objects which can absorb
heat. These precautions
will allow the room
to remain cool even
during the hottest
hours of the day.
People in the room
should keep at a distance
of at least one metre
from the appliance.
If, due to lack of
space or other reasons,
one has to remain near
the appliance, the
airflow must be directed
away from the person
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A
Brief
Explanation
of Evaporative
Cooling
In
our range of cooling
equipment we have
a wide selection
of Evaporative
Coolers which are
suitable for cooling
areas from
120ft² (11.1m²)
to in excess of
2000ft² (186m²). These
machines use a
supply of water
and, unlike air
conditioners, do
not have exhaust
hoses or outside
condenser boxes.
They are different
from air conditioners
in that they provide
cooled air rather
than refrigerated
air.
On a warm summer
day, if you were
to put your arm
in a bucket of
warm water and
pull it out,
you would feel
a slight chill.
The cooling would
not be due to
the temperature
of the water,
but rather, the
evaporation of
water off your
arm. Evaporative
cooling is a
very powerful,
yet inexpensive
method of cooling.
In very dry climates,
everything from
residential homes
to large buildings
use evaporative
cooling to reduce
air temperature.
Though widely
used, the actual
mechanics of
how evaporative
cooling systems
operate are difficult
to comprehend.
With proper understanding
of evaporative
cooling, problems
can be avoided,
and the cooling
ability of these
systems can be
increased.
What
is evaporative
cooling?
When
trying to understand
evaporative cooling,
it may be best
to think of air
as a type of sponge.
Like a sponge,
as air comes into
contact with water,
it absorbs it.
The amount of water
absorbed depends
largely on how
much water is already
in the air. After
all, how easily
you clean up a
spill depends on
how dry a sponge
you are using.
The term ‘humidity’ describes
the level of water
in the air. If
the air holds 20%
of its capacity,
the humidity would
be 20%. A humidity
of 100% indicates
that the air is
holding all the
moisture it can.
The lower the humidity,
the more water
the air can hold,
and the greater
amount of evaporation
that can take place.
When describing
the amount of
moisture in the
air, the term
relative humidity
is used because
the sponginess
of air changes
relative to air
temperature.
The warmer the
air, the more
spongy it becomes
and the more
water it can
hold. As a result,
we must describe
the level of
humidity relative
to the type of
sponge we are
talking about.
Is it a 50° F
sponge or an
80° F sponge?
An 80°F sponge
will hold more
water at 50%
humidity than
a 50°F sponge.
How
is the Cooling
Produced?
In
order to evaporate
water, heat (energy)
is required. In
fact, to evaporate
a gallon of water
requires almost
8,700 Btu’s
of heat. Where
does this heat
come from? From
whatever the water
is in contact with
as it evaporates.
This could be a
pavement, your
body, a tree or
from the air itself.
As the heat is
removed from an
object, the temperature
of that object
is decreased.
It is important
to realise that
the temperature
of the water
does not have
a great effect
upon the cooling
produced through
the evaporation.
If you were to
place a gallon
of 50°F water
on a warm pavement
(90°F) it would
produce 9000
Btu’s of
cooling. A gallon
of 90°F water
would produce
8700 Btu’s
of cooling, only
a 3% difference.
After all, if
you were sprayed
with water at
either temperature
on a hot day,
you would feel
much cooler.
With an evaporative
cooler, air is
drawn through
a wet filter
pad. As the air
moves over the
wet pad, water
is evaporated
off the pad removing
heat from the
air. The pad
basically acts
to support the
water within
the stream of
air entering
the building.
The key to getting
the most out
of an evaporative
cooling system
is to maximise
the amount of
air that comes
into contact
with the moisture
added to the
room/area. This
makes sense because
the best possible
way to clean
up a spill with
a sponge is to
go over it time
and time again,
flipping the
sponge over and
over, making
sure that the
dry sections
of the sponge
come into contact
with the water.
Evaporative cooling
pads typically
produce the most
evaporative cooling
because they
are designed
to provide the
maximum interaction
possible between
water and air.
An evaporative
cooling pad has
a huge amount
of wetted surface
area. This allows
the air entering
the room/ area
to become totally
saturated with
water resulting
in the maximum
cooling effect.
Some
practical tips:
Evaporative coolers
work best when
relative humidity
is below 70%.
Cold water does
not significantly
increase the
cooling efficiency
of an evaporative
cooler.
Evaporative coolers
must only be
used in areas,
which have good
natural ventilation
or adequate mechanical
air extraction
units.
EVAPORATIVE
AIR COOLER
TEMPERATURE
DROP CHART.
These
charts show
the approximate
output temperature
at the grill
of an evaporative
cooler given
the ambient
temperature
and relative
humidity %
(RH) combination.
The figures
assume a minimum
pad saturation
of 80%.
The
first chart
shows ºC
(Centigrade)
the second ºF
(Fahrenheit).
|
Ambient
Temp.ºC
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Relative
Humidity
%.
(RH%)
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10
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20
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30
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40
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50
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60
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70
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80
|
90
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10
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4
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4.5
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5.5
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6
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7
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7.5
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8
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9
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9.5
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15
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7.5
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8.5
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9.5
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10.5
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11
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12
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13
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13.5
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14
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20
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11
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12
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13
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14.5
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15.5
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16.5
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17.5
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18.5
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19
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25
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14.5
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16
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17
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18.5
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20
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21
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22
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23
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24
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30
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17.5
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19.5
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21
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22.5
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24
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25
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26.5
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28
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29
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35
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--
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23
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25
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26.5
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28.5
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30
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31.5
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32.5
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34
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40
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--
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26.5
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29
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31
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32.5
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34.5
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36
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37.5
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39
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45
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--
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--
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32.5
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35
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37
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39
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40.5
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42
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44
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50
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--
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--
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36.5
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39
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41
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43.5
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45
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47
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48.5
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Ambient
Temp.ºF
|
Relative
Humidity
%.
(RH%)
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10
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20
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30
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40
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50
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60
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70
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80
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90
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50
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38
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39
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41
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42
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44
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45
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46
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48
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49
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60
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45
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47
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49
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51
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52
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54
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56
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57
|
58
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70
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52
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54
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56
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59
|
61
|
63
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65
|
67
|
68
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80
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59
|
62
|
64
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67
|
70
|
72
|
74
|
76
|
78
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90
|
65
|
69
|
72
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75
|
78
|
80
|
83
|
86
|
88
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100
|
--
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76
|
80
|
83
|
87
|
90
|
93
|
95
|
98
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110
|
--
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83
|
88
|
92
|
95
|
99
|
102
|
105
|
108
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120
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--
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--
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95
|
100
|
104
|
108
|
111
|
114
|
118
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130
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--
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--
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103
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108
|
112
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117
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120
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124
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127
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Please
note the figures
in the above
tables are
approximate
and for guidance
only.
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