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

--
David

In article ,
gremlin_95 writes:
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?

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.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On 23/05/2012 22:40, Andrew Gabriel wrote:
In ,
writes:
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?
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.

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?

--
David

In article ,
gremlin_95 writes:
On 23/05/2012 22:40, Andrew Gabriel wrote:
In ,
writes:
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?
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.

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

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.

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?

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).

Or is this better than the negative pressure effect anyway?

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

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On 24/05/2012 13:03, Andrew Gabriel wrote:
snip
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 see, my unit at the moment is fitted like that (no internal ducting)

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

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?
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).

Or is this better than the negative pressure effect anyway?
If you can better seal the room, the cooling, and more importantly
the dehumidifying, will be more effective


Thanks Andrew


--
David