Portable air conditioner modification

[gremlin_95]

Hi all,

I have a 4-5 year old Amcor 9000btu portable air conditioner up in my room, it seems to do a fairly good job of cooling the room although it does seem to work pretty hard to keep it comfortable (around 22ºc -

23ºc), that might sound quite high but it's a lot more comfortable since the humidity is reduced.

Anyway, I have read about this type of air conditioner creating negative pressure in the room which as a result causes it to pull in warmer more humid air from the surrounding areas, this is because air from the room is used to cool the condenser and exhausted outside. I remember another poster on here saying they modified the unit so it would use outdoor air instead to cool the condenser, I was just wondering how much of a difference it would make? Apart from cooling down a bit quicker initially when the air outside is cooler and obviously not pulling in warm air from the rest of the house..

I have inspected the unit closely when I had it open to clean it and it appears to have 2 completely separate air paths, there is an intake with a carbon and mesh filter which leads to the cooling coil and back in to the room and another 2 towards the bottom which just have a mesh filter on that leads to the hot condenser and out through the exhaust..

All I reckon I will need is some cardboard, flexible ducting and some tape, tbh it's an experimental thing but was wondering if it would be worth the effort?

Cheers

[Andrew Gabriel]

That's exactly what I did, and it made a big difference. Eventually, I fitted a fixed split unit system, which is much better still.

[gremlin_95]

Great, will some ordinary 100mm or 125mm flexible ducting do the job?

Also, when the outside temperature gets higher than what the room temperature is, will the performance be reduced given that when running as a single hose unit it would be using the cooler room air to cool the compressor? Or is this better than the negative pressure effect anyway?

[Andrew Gabriel]

Yes, I used 125mm ducting. The exhaust duct itself gets very hot. I was toying with the idea of core drilling through the wall in the right place so the unit could stand against the wall with no internal ducting, but eventually thought better of making a portable unit into a fixed one, and bought a fixed unit instead.

I was given the original portable unit by someone who bought it and then claimed it didn't work. This was entirely down to not being room sealed - it's actually one of the more powerful ones available and works very well when modified as above.

No - exactly the opposite, as the unit won't be fighting with itself. Once the room was properly sealed, the unit would drop the room temp and cycle on and off on its thermostat. Beforehand, it would run continuously and still not reduce the room temp much (although the drop in humidity was still worth having).

If you can better seal the room, the cooling, and more importantly the dehumidifying, will be more effective.

[gremlin_95]

I see, my unit at the moment is fitted like that (no internal ducting)

Thanks, looks like I will be doing this modification soon!

Thanks Andrew