Every
window air conditioner should be properly
sized to match the
room area it will be cooling. If not the air conditioner will not
be successful removing moisture from the air. Since it's the moisture removal that actually produces the feeling of
cooling the result will be a disappointed consumer.
Unfortunately in their rush to purchase a window air conditioner
many people buy
too large a model. For instance if you require a 5000 BTU unit ,
purchasing a 10,000 BTU unit may not give you twice the cooling.
In fact, too
large a unit can actually provide less cooling than a smaller,
properly sized unit. This is because with an oversized air
conditioner cools the air in front of itself so quickly that it
shuts off prematurely. Therefore, its run time is too short and it doesn't
remove enough moisture from the room to produce a feeling of
comfort. This is called, 'short cycling'. So
if
your new window air conditioner seems to cycle off and then back on every few minutes, and
does a poor job of cooling, it may be oversized for the room.
Air
conditioners are rated in BTU’s. British Thermal Units are a
standardized measurement that indicates exactly how much heat is being transferred.
The larger the BTU rating of the air conditioner, the faster it
can remove moisture from the room, and the larger the
cooling effect it can produce. A
window air conditioner used in the average household bedroom can be
as low as 4000 BTU. While 5000, 6000, and 8000 are the most common
sizes purchased for home use. Large open areas such as an open
concept family room or rooms that contain a lot of people or
equipment may require a slightly larger air
conditioner.
How
you determine what size you need
Following
is a basic sizing chart for calculating the window air
conditioner needed for a room. Calculate the size of the room by
multiplying the width of the room by the length of the room. Use
your room size to determine what BTU's are required to cool that room size.
Room in Sq Feet
Room in Sq Metres
A/C size in BTU’s *
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100-250
9-23
5000-6000
250-400
23-37
6000-8500
400-550
37-51
8000-11000
550-875
51-81 11000-15000
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Before
purchasing your window air conditioner take the time to do this
simple measurement. Go to the store prepared with the knowledge of
what basic size you require. The sales person may have a different
opinion. They often suggest a larger air conditioner,
'for-just-a-few-dollars-more'.
If
still unsure, check the outside of the air conditioner box. Most
manufacturers put a small sizing chart right on the box. Use it to
confirm the size you know you need, and what size that particular
manufacturer suggests.
*Based
on a room occupied by two adults, having an average insulation,
number of windows, and sun exposure.
By
Donald Grummett
Copyright © 2005
Donald Grummett. All rights reserved
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