Portable air con

[Steve]

9000 BTU will be about 1kw of 'lectric. They have pretty big compressors.

Is that full power though? Im assuming they have variable settings?

The compressor in standard air con units (certainly the cheap ones) are not variable. They start up with a shudder and pull a lot of current while doing so, like your fridge, but a lot more. And while running, they run at one speed. The compressor cycles on and off on a thermostat, so it isn't running constantly.

Newer, more expensive air con systems have variable compressors which use a technology called DC inverter. These are very quiet and they do run nearly constantly. Because they are variable, they dont draw high startup current, and this increases the lifetime of the compressor, as it reduces the strain on startup.

 

[gcol]

Can't praise my portable unit highly enough. 3 years old now and still going strong. Has been worth every penny of the £250 I paid for it. Sure they aren't silent (you get used to it), but it is superb being tucked up in bed under the duvet in the middle of Summer.
Mine's piped through the wall and is therefore not portable but I didn't buy it so that I could move it about - I bought it cause it was cheap. If it broke today, I'd buy another tomorrow - can't say fairer than that.

Edit: that one in your link looks fine.

Which model have you got? My son want one in the loft conversion bedroom, it's like a sauna up there and is the running cost okay?

Pretty sure it's an Amcor or something like that - I'll post tomorrow (save me going upstairs now and waking the missus), and I think it uses about 300W. Of course this figure may change tomorrow when I read the back of the machine. I think it's either an 8 or 9000 btu thingy. You son will love you forever if you get him one.

OK as promised, it's an Amcor AMC-10000E, which makes it a 10,000btu unit and consumes 830W. Hope this helps.

 

[ColJack]

i'd go for the "through the wall" one...

just 3 holes in the wall, no external condenser.. used as a heater in the winter...

 

[gcol]

Looks good ColJack, I wonder why it needs 2 large holes - usually just one? The small one will probably be the water outlet.

 

[ColJack]

since there is no outside unit, it has no pipework to run out except for the drain..

it needs air in and air out..

it takes heat from one and transfers it to the other..

in the summer this cools the air comming in and heats the air going out..
in the winter this is reversed..

 

[gcol]

My unit just has one exhaust pipe - it takes the hot air from the room and blows it outside to warm the neighbours. I would have thought that when in heat mode it would still take the air from the room and heat that. Still don't see why it needs 2 large holes.

 

[Balenza]

gcol wrote

Still don't see why it needs 2 large holes

Fresh air in. Exhaust air out. ?


The Airforce units are (and probably always will be) BUDGET air conditioning systems! - They will struggle to match the performance of the established Japanese manufacturers - Check out the Government's Energy Technology List (www.eca.gov.uk/etl) of tested and approved low energy usage heat pumps - The Airforce Climate Control system isn't on it because it's Coefficient of Performance is extremely poor by modern standards.
All the premium brand air conditioning manufacturers and most of the "second division" guys have moved to inverter drive compressors to push their system's energy levels efficiency levels far beyond the "A" energy label criteria. The airforce climate control system remains a Fixed Speed Compressor system with consequently higher energy consumption and lower efficiency.

 

[gcol]

Fresh air in. Exhaust air out. ?

Surely that's not very efficient? If you have it set to "cool" then you'd want to be cooling the air that's already in the room rather than taking in hot air from outside and having to cool it? Once the air in the room is cool it's going to take less effort to keep it cool that to continually chill the warm air from outside.

 

[Balenza]

I agree gcol but surely its taking a percentage of fresh air from outside and exhausting that same percentage.

 

[gcol]

I've no idea, I was just saying.

 

[Softus]

Do you have a loft water tank and vented hot water cylinder and some space for another tank

If so give some thought to a pre heater tank for the hot water. A fan circulates the hot air through a heat exchanger to warm the water in the pre heat tank and returns the cool air to the room.

I can't see how this could possibly be implemented economically

If you're talking about pre-heating the cylinder, then this is a non-starter, because even the water at the base of the cylinder it above room temperature.

If you're talking about the cold storage cistern, then you'd need some reasonably sophisticated controls to prevent the water temperature getting too high and raising the risk of bacterial growth, that being the whole reason for lagging the cistern in the first place!

 

[Balenza]

I've no idea, I was just saying.

Aaah. They need air delivered to the condensor in order to reject the heat absorbed at the evaporator along with the heat of compression.
So because their is no outdoor condensor unit then air has to be drawn in from outside, through the now internal located condensor and back outside again.
Their are probably some internal air dampers on the unit to let the room be ventilated to some degree also.

 

[Steve]

The ones with one exhaust pipe blow air from the room over the "hot bit" and blow it outside. This means air must somehow enter the room, as it is blowing air outside.

The ones with two pipes, take air from outside over the "hot bit" and blow it back outside. Much more efficient.

At least this is how i assume it works. If its a bit more sophisticated, it will provide fresh air into the room by some means too, but even the best commercial units aren't piped to do this.

 

[Balenza]

Crafty wrote

but even the best commercial units aren't piped to do this

.

AAaah. But they are.
On the ceiling mounts a duct panel is fitted above the trim panel.
Its about 70mm deep so the indoor unit is just raised up providing the height is available above it.
A 100mm duct spigot is moulded on one side . This enable's a flexi duct to be connected between the duct panel spigot and an outside air vent. A damper can be fitted to adjust the amount of fresh air that is drawn in by the operation of the indoor units fan.

 

[Steve]

Balenza, I know most are capable of it, its a function on their controllers. I was highlighting that they usually aren't installed that way! I should have been clearer!

OOI, I thought the outside air was drawn in by a duct on top of the ceiling cassette? I've never seen it done before, thats all.