Mobile Air Conditioning Units

[telboy1938]

Do all mobile air conditioning units have to have an exhaust hose? I need Tom site one in an inside room with no means of reaching outdoors. Thanks

[donny48]

Yes, as far as I know they do,
http://www.which.co.uk/reviews/air-conditioners/article/how-to-buy-an-air-conditioner

[murraymints]

morning Donny XX..OO..XX..

[Old_Geezer]

Proper ones do. There are some portables that seem to be air conditioning but which rely on outputting damp air by exaporating water from it's tank. They are less impressive.

[murraymints]

My units in Herts were all mounted on outer walls with flues

[gangesboy]

No they don't all need a hose. You can get an evaporative cooler which uses water to cool the hot air.
See here
https://www.quora.com/What-are-portable-air-conditioner-without-window-exhaust

[donny48]

Good morning Minty, XXOOXX

[donny48]

Portable air conditioners can’t be ventless because they all produce hot exhaust air as a result of the heat exchange process that produces the cold air. That hot air must be vented to the outside because if it is not, you will get a net temperature increase in the room.

What people call ventless or vent free AC is actually a swamp cooler/evaporative cooler that cools the air by evaporating moisture. Since there is no hot air produced, there is no need for a vent

[donny48]

We tried the ventless, not very good. We tried the portable ones, extremely noisy. I found an old office one, re-conned it and fitted it to the outside wall of the bedroom, ideal.

[mikey4444]

Donny has it right. Proper AC units always need an exhaust, otherwise all they do is to re-circulate all the hot air.

[donny48]

In fact without a vent a proper air-con unit will increase the temperature, the process of cooling the air leaves you with the heat you have extracted.

[gangesboy]

I haven't tried the evaporative type. I have a Duracraft vented mobile which is extremely efficient (albeit a bit noisy). Bought it 5 years ago and it still works very well

[donny48]

I would recomend anyone thinking of buying one of these evaporative units to firstly hear one running and secondly to look at the figures given to see if you consider it effective.

[mikey4444]

I have a proper mobile AC unit, and its very expensive to run !

[donny48]

They are expensive to run, you are running a powerful little compressor and a fan.

[Togo]

The trick with the evaporative, twice a year portable units, is to put freezer blocks in the water tank. Change them regularly.

[Garaman]

When you say you have 'proper mobile AC unit', Mikey, do you mean a dual-hose unit?

Single-hose units aren't very efficient as they draw warm air into the room from outside to replace the hot air that has been expelled.

[mikey4444]

Garaman....not sure. All I know is that it has a small refrigeration unit included in it. As long as I can vent it, it is works very well but the cost means that I mostly rely on a tower fan.

[Garaman]

Mikey, you say that it works well but is costly to run, and I was just suggesting that if it is a single-hose unit, one of the reasons it will be costly to run is that those units don't work very well (as in efficiently). Instead of cooling the air in the room and switching off, they continually draw more warm air into the room to replace the air that they have expelled and of course they have to cool that air too. Hence you are paying to cool air that was outside.

[Old_Geezer]

One has to do something with the extracted heat. Unsure what the better alternative is. Replacing hot with cold from the unit and warm from the next room seems a reasonable solution.

[ivor4781]

air coolers are useless they increase the humidity , i had one,got rid, i got a 12.000 btu air con unit ( amcor make )its aprox 18p an hour to run not bad as you dont need it it for many months in the year anyway and vent essential naturally