Here is a wonderful titbit of information that will make
you the hit at the annual dinner of the Denpasar Toastmakers
Club.
Did you know there is no such thing as “cold.”
Cold is in fact a worldwide con created by exuberant salesmen
who want to sell fridges to Eskimos.
You see “cold” doesn’t exist, cold is in
fact an “absence of heat”.
To make heat you burn electricity, gas, coal, sweaty socks
or any other energy to turn it into heat energy. In an electric
fire or toaster all those little electrons dash round and
get so excited that they generate lots of heat. 1 kilowatt
of electricity will produce 1 kilowatt of heat (well nearly).
BUT if they run around backwards they won’t produce
cold. You can’t create cold. To make something cold
we have to remove heat so we use a different process. In my
recent article on Nasty Gas (see the Bali Advertiser or Mr
Fixit websites) you will find the cooling cycle used in refrigerators
and air conditioners.
One of the great things about Bali is the weather, we enjoy
a tropical climate but the sea breezes make it very liveable
and keep the mozzies away. Many of us get used to the temperature
and sleep with a ventilated room (good for the environment)
but for many people an air conditioner is a must particularly
when it gets up to treacle toffee on the stickiness scale.
Air conditioning is a big subject but I will try and keep
it simple. Firstly we need to understand a few things.
“How big is your peka?”
“I beg your pardon!”
In Indonesia the power of air conditioners is usually stated
in pekas (what!). A peka in fact comes from the Dutch PK which
is short for Paarden Kracht which translated means horse power
(HP) - but not quite. A PK is in fact a metric horse power
which is slightly smaller than a real horse power, this is
probably because the Dutch had smaller metric horses. One
horse power is the equivalent of 746 watts while a PK is 736
watts or 0.736 kilowatts.
The amount of cooling an air conditioner achieves is measured
in BTUs (an archaic imperial measure known as a British Thermal
Unit). To impress the Toastmakers you might like to tell them
that a BTU is the amount of heat required to heat one pound
of water through one degree Fahrenheit.
During the height of the British Empire a fiendish plot was
hatched whereby British Thermal Units were spread liberally
all over the world to confuse scientists and engineers and
give Britain a technological advantage. The plot was finally
exposed and Europeans converted all their BTUs into Kilowatts
at an exchange rate of 1 Kilowatt for 3,413 BTUs.
How much cooling can be achieved by an air conditioner is
determined by it’s power and it’s efficiency.
This is measured as COP (Coefficient of Performance) which
is the ratio of electricity input to cooling output. Back
in the days of window mounted box air conditioners you could
expect a COP of around 1.5 ( 1 kilowatt of electricity achieved
1.5 kilowatts of cooling). Nowadays with modern split air
conditioners you can expect a COP of up to 4.5 (1 kilowatt
of electricity will produce 4.5 kilowatts of cooling).
“Just a minute! How can 1 kilowatt of electricity produce
4.5 kilowatts of cooling?“
You must remember that an air conditioner is not converting
energy like an electric fire converts electrical energy into
heat energy, we are simply moving heat energy from inside
your house to outside.
A modern air conditioner is in fact a heat pump, it pumps
heat. It is also interesting that many air conditioners are
“Reverse Cycle” they can (unlike the electric
fire) run backwards pumping heat from outside your house to
inside your house. A modern heat pump is four times as efficient
at heating your house than an electric fire.
So you want to buy an air conditioner? Firstly you need to
determine how much heat you need to remove from your room(s).
A detailed calculation is needed including the floor area,
the insulation of the walls and ceiling, the height of the
room, the number of windows and doors, how much sun comes
into the room, how many people are in the room (and how hot
they are!) and the electrical appliances in the room that
produce heat including light bulbs. From this the size in
pekas can be determined.
This is complex but as an extremely rough guide the following
table may (or may not) help:
PK Input
Kwh Input
Very Well Insulated Room
qMeters
Medium insulated room
SqMetres
Badly
Insulated
Room
SqMetres
1
0.74
16
11
5
1.5
1.10
25
16
8
2
1.47
34
22
11
2.5
1.84
43
28
14
3
2.21
52
34
17
This is based on a split air conditioner with a COP of 4.
What make should you buy? Well basically you get what you
pay for. Generally regarded as the better air conditioners
are Daikin and Mitsubishi. At the other end of the scale names
like “Chou Well Hung”, “Poo” and “Dung”
speak for themselves.
There are many to choose from. Toshiba tend to be a little
more expensive than the others, particularly on spare parts,
while brands such as Panasonic, LG, Sanyo, Samsung, etc compete
at equal levels and try to outdo each other with extra features
such as self cleaning, ionisation, bacteria filters, tea makers
and toenail clippers. A rugged and reliable choice is Mitsubishi
Heavy Industries (not the same as Mitsubishi Electric).
As a final comment, the efficiency of your air conditioners
will drop quite markedly as the filters get dirty. It is a
good idea to get them cleaned and serviced regularly, perhaps
every three months if you use them a lot.
If you don’t understand a word of all this don’t
worry about it, just have another glass of wine and put your
feet up with a good book.
Here is a wonderful titbit of information that will make you
the hit at the annual dinner of the Denpasar Toastmakers Club.
Phil Wilson
Phil Wilson a project director for Focus Indonesia and a partner
of MrFixit property maintenance services. Opinions expressed
are those of Phil Wilson. If you have any questions or comments
related to property maintenance he can be contacted at the
office on 0361 288 789 or through the website at www.mrfixitbali.com
Copyright@2007 Fixed Abode
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