Aircon Question (Slightly O/T)

[Shokka]

Bought a Toshiba Aircon unit from a classified ad and it works in a slightly different way to my other aircon unit (B&Q) and I wondered why.

Its a floor standing unit on wheels with an exhaust hose which goes through a hole in the wall, same as the B&Q unit.

However, it has a large water tank which needs refilling, whereas the B&Q one doesn't. It's NOT an evaporative cooler, so what is the water needed for?

It works *really* well, far better than the B&Q model so the water is obviously doing something..but what?

shokka

[sm_jamieson]

What's the model number. - should be able to look up on toshiba website and find a manual or something that would explain. Simon.

[sm_jamieson]

Um, are you sure the water tank is not just the one to collect the water extracted from the air ? The you empty, not fill ? Or are you saying there are 2 tanks ? Simon. Or

[Shokka]

The manual mentions nothing about what it's for, just that it needs to be filled.

The schematic shows the usual fridge compressor, fan, switches and control board so no clues there.

The water doesn't come out of the louvre on the front (The air feels dry) and in any case the machine has a dehumidification mode.

I wondered if the water was to improve the removal of heat via the exhaust tube?

I *think* the model number is RAC-08 (Or similar). It was made in the early to mid nineties.

shokk

[Shokka]

One large-ish tank that you fill up from the tap. I'm wondering if it uses it to improve the efficiency of heat removal via the exhaust pipe? The air that goes out of the exhaust tube feels damp.

Whatever it does and however it does it, it works extremely well.

shokk

[meow2222]

caution: wild guess approaching. Does it trickle over the hot heat exchanger to increase exhange rate? If it did it would slowly scale it up, so no.

Maybe its a twin cooling system, ac then evaporative. That would give more cooling than ac alone, and the evap cooling would work well with ac-dehumidified air.

NT

[Mike Harrison]

Is it maybe an evaporative cooler with a heat exchanger, so the warm damp air goes out of the exhaust hose while cooling the air on the room side of the exchanger.

[Andrew Gabriel]

Mine does that using the water condensed from the evaporator (cold element), so no scale problem.

[marvelus]

I've got a RAC-16sw. As Mike Harrison says its an evaporative cooler with the steam pumped out throuhg the exhaust. I think they offer a more powerfull cool for the size of unit but are a pain to keep topped up.

[Shokka]

Yup. Took it apart at the weekend to have a look! It's not an evaporative cooler in the common sense, in that the evaporation is used to cool the 'hot' air conditioner circuit rather than cool the room directly.

Biiig heating coil that makes the water evaporate which is then pumped up the exhaust hose, taking heat with it.

Because the 'steam' is a more efficient carrier of heat it means less air is pumped up the exhaust hose and thus less (Hot) air is drawn into the room being cooled, to replace it.

(The instructions for the unit includes directions for descaling the coils which it says should be done regularly.)

Yes, it's a pain to keep refilling but it works *much* better than other single hose air conditioners. I'm surprised that other manufacturers don't use the same method.

Thanx to all who replied,

shokk

[<me9]

My aircon pumps the condensate into a tray below the fan blades which splat the water over the heat exchanger, acheiving the same result, without having to fill up with water. I wonder if it increases the liklyhood of propogating legionella bugs?

[marvelus]

You need to find a chemist that will sell you citric acid and sodium bicarb without thinking your a druggy :) I havnt done mine for a few years and it was performing OK last night. But I live in a soft water area.

When I got mine 18 years ago it was the *only* portable AC you could get in this country, now you cant get this type. As another poster said its probably a legonella death trap :)

[marvelus]

The Toshibas use the condensate too but will get through an additional gallon of water with about 5-6 hours continual use.