Question:
How do portable units expel the heat?
Most units I have used in the past either have a heat exchanger (and fan)
mounted outside, or require a vent pipe for warm air to be blown out, so how
does a portable unit which says keep doors and windows closed expel the
heat?
Answer:
If you recirculate the air, forget it - it'll add to the heat in the
room. Opening a window and dropping the exhaust pipe out can help, but
it doesn't really help much because more warm air comes in the window.
The only solution is a firking great 4in hole thru the outer skin of
the house, thru which you poke the exhaust pipe.
But a 12x12 room? No chance. I've got 2 PCs in my study, combined they
chuck out about 500w of heat. The mobile aircon just about keeps up,
but only just. If I go sit in the study to admire the slightly lower
temperature it's over the top. And my study is something like 6x9.
Basically these mobile units are a pile of pooh. Don't bother is my
suggestion. I understand from comments made by others that you really
need a dual unit, where the fan is inside and the heat exchanger is
outside (I hope I remembered that right). Expect to pay a grand or
more for something like that.
As others have said the water filled ones aren't much cop (although some can
be filled with ice) and the portable proper ones don't have much power. A
friend of mine has one and it's about 500W or less of cooling. If you think
about how much energy it takes to heat a room up then it needs the same sort
of power to cool it down. And he has problems sealing around the exhaust
pipe (uses towel stuffed around the window).
