location of capillary tube

[afeef]

hi all
i notice that all split a/c systems :
the location of capillary tube is within the condensing out side unit not within evaporator inside unit.
my question : why?

[rbartlett]

hi all
i notice that all split a/c systems :
the location of capillary tube is within the condensing out side unit not within evaporator inside unit.
my question : why?

my answer

why not?

cheers

richard

[andy bailess]

With this system there is no liquid line thus reducing refrigerant charges,this means higher efficiency and smaller compressors with no liquid being pumped around a system.
Yuo do need to remember that critical charges are very important on these systems.

regards

andy

[rbartlett]

With this system there is no liquid line thus reducing refrigerant charges,this means higher efficiency and smaller compressors with no liquid being pumped around a system.
Yuo do need to remember that critical charges are very important on these systems.

regards

andy

I'm interested in a few things here..

1) why does no liquid line mean higher efficiency
2)why are smaller compressors needed in these systems
3) why are these 'charge critical' when a Daikin is charged to 30 metres

cheers

richard

[afeef]

my openion is :

if we use the pipe running close to suction pipe as liquid line , this will give subcooling to liquid ,which will increase the efficincy of system.
but using this pipe as part of evaporator will have heat loss along its length , this will degrease the efficincy.
am i right??
thanks

[wizzer]

rbartlett my answer

why not?

cheers

richard

Not very helpful there Richard.Do you know why?

[rbartlett]

rbartlett my answer

why not?

cheers

richard

Not very helpful there Richard.Do you know why?

The answer was not quite a flippant as it seems. I was around when the first Japanese splits were imported in a major way so as I had just joined the design team of a well know UK manufacturer Qualitair who used a liquid line we had to ask this very question..Our head of design had just come back from japan on a fact finding mission and was quite shocked how far behind we were even though we though we were second biggest in the UK.
I also knew Qualitair had no future when it started badge engineering Toshiba splits back in '83.

This has been discussed here many times before but I'm now extremely interested in Andy's assertions so I won't join the debate till he answers my questions

Cheers

Richard

[wizzer]

This has been discussed here many times before but I'm now extremely interested in Andy's assertions so I won't join the debate till he answers my questions

Cheers

Richard

Thats a bit hard on Andy's reply i have heard many engineers say the same thing,and i have read far worse posts in this forum than that from non engineers.

I would love to know your answers on the above and why andy's assertions are wrong please enlighten us all who have been told the same thing.

P.S i'll pick up your answer tomorrow early start

[juandeloscabos]

Hi Guys.......
You Will Find Answers Checking Out R-22 P-h Charts

[rbartlett]

Thats a bit hard on Andy's reply i have heard many engineers say the same thing,and i have read far worse posts in this forum than that from non engineers.

I would love to know your answers on the above and why andy's assertions are wrong please enlighten us all who have been told the same thing.

P.S i'll pick up your answer tomorrow early start

At no point have I said Andy was wrong.


Cheers

Richard

[Peter_1]

The reason why they do it is simple: to avoid the 'sssssssissing sound' you should hear when they install it in the indoor unit.
Second reason, easier to fabricate a heatpump when all the controls are in the outdoor unit.

[afeef]

oh ,,,yes peter , i beleve you are right
the sssssing sound is one of the reasons to locate the capillary at the out side unit
good point ,,,,,thanks
afeef

[Mohammed Qasim]

I want to say not all split systems have outdoor capillary
tubes ,some of them are indoor capillaries ,and as they mentioned above it is a matter of cost .

[S.K.VARDE]

EARLIER

Locating the capillary close to the cooling coil is certainly, benificial with a view to better COP/ EER of the system.

But it is experienced that doing so, it usually produces unpleasent intermittent Hissing sound due to flow of refrigerant. Also it may creat "Kir-Kir" sound as the coiled capillary vibrate in it self as the varying quantity of the refrigerant metered to evaporator due to varying load.

To avoid this sound the usual practice was to wrape the coiled capillary with wet & oiled glass putty. but it does not provide complete and permanent solution.

NOW

Later on during 80's some AC manufacturers started putting capillary at the condensing unit and tried to keep the sound out with the condensing unit which is remotely placed.

Yes, this resulted the soundless cooling unit compromising with the poor COP comparatively.

What else, yes, this is the total thermal comfort of human being.

[wizzer]

Who's bothered as long as it works

[The MG Pony]

I'm botherd if my machinery is wasting more power then needed!