AirCon loss of performance per meter

Air conditioning, fans, and anything related to keeping it cool, such as insulation. This would include any posts generally discussing how to keep it cool, such as which types of blocks are better insulators.... ideal wall thickness for keeping an A/C house cool, etc.

Moderators: Sometimewoodworker, MGV12, BKKBILL

AirCon loss of performance per meter

Postby Nawty » Thu Nov 22, 2007 7:42 pm

Anyone know about the loss of performance for a system with various lengths to run from the compressor outside to the unit inside.

Have been told various things, need to know the REAL thing.
User avatar
Nawty
 
Posts: 804
Joined: Mon May 07, 2007 12:23 pm

Postby jazzman » Fri Nov 23, 2007 7:26 pm

Can't give you the scientific facts & figures, but condo builders have now
realised that all the units for up to a seven storey building can be located in the basement or on the roof with out significant losse, and avoiding having the unsigtly things installed on every balcony. The real experts in this field are [url]http;//siamgpi.com[/url], but they may charge a small sum for a feasibility study for a secific project.
jazzman
 
Posts: 2161
Joined: Wed Dec 06, 2006 9:11 pm
Location: Thailand

Postby Nawty » Fri Nov 23, 2007 8:53 pm

So why then did the dude putting in my aircons refuse to put them ALL where I wanted, 2 in particular he said the loss of efficiency would effect them and as my house is a lot of glass, i did not want any loss. So we put them where recommended and where I did not want them really.

The difference in meterage from one postion that I wanted them to where he wanted them was about 6 or 7 meters.
User avatar
Nawty
 
Posts: 804
Joined: Mon May 07, 2007 12:23 pm

loss of performance

Postby pklongball » Sat Nov 24, 2007 8:00 am

Maybe the installation technician was only worried about the loss of "his" performance?

Could it be he just did not want to do the extra work involved to run the tubing another 6 or 7 meters? How many turns and walls would he have to penetrate and find a new way to route the electrical?

I have a friend who has all of his units in the back of the house,,,,,,,,,,no problems he's aware of,,,,,,,,,,,,except he had to pay extra for the additional distance and material.

Pk

:)
User avatar
pklongball
 
Posts: 375
Joined: Mon Jun 04, 2007 10:32 am
Location: Ban Chang-Phala Beach

Postby Nawty » Sat Nov 24, 2007 4:46 pm

The extra distance was not a problem for extra work as the concrete was bored where required by other workers, so they did not have any extra hard labour.

It was purely a 'loss of performance' argument from him and as I know crap about aircon, I nor the builder did not want to argue to much, or do as I wanted and end up with a loss as advised.

It's all a learning curve and if I can get some real accurate advice on this from experts somewhere somehow, then the next house will not have the same problems.
User avatar
Nawty
 
Posts: 804
Joined: Mon May 07, 2007 12:23 pm

Postby atlas_shrugged » Sun Nov 25, 2007 10:51 pm

The brochures I've seen just state a single number, not a loss per meter or anything like that. My guess is that as long as you stay within the given lengths & heights, the unit will operate within the normal range. The Daikin brochure I have in front of me says the "maximum interunit piping length" is 30 meters and the "maximum installation level difference" is 15 meters (5 floors!). It also states that both the liquid and gas lines must be insulated.

Got to get that compressor away from the head of the bed!

-Atlas
atlas_shrugged
 
Posts: 41
Joined: Wed Jun 29, 2005 4:58 pm
Location: Pattaya

Postby atlas_shrugged » Mon Nov 26, 2007 9:23 am

Oops, now I see in the (very) fine print at the bottom that the nominal cooling capacity is measured at 7.5 meters equivalent refrigeration piping, horizontal, whatever that means. Which implies that length does matter, so to speak. But it doesn't mean that if you go over 7.5 meters you're immediately hosed.

-Atlas
atlas_shrugged
 
Posts: 41
Joined: Wed Jun 29, 2005 4:58 pm
Location: Pattaya

Postby Nawty » Mon Nov 26, 2007 10:11 am

Length does matter in so many situations.

One would think that if the pipes are continuous lengths..ie no joints..and all the piping was insulated properly and again if all the piping was under cover from sunlight and direct weater, which most of it should be in roof or wall cavities....then where can the performance loss be ??

Is it possibly that the motor has to work harder to pump it further and that is where the loss is ?

Would love to put in 2 aircons, one at the recommended maximum and the other at normal lengths and just see what the difference in both actually keeping cool and electricity usage.
User avatar
Nawty
 
Posts: 804
Joined: Mon May 07, 2007 12:23 pm

Postby tintin » Wed Nov 28, 2007 6:45 pm

Lenght and height matters. The cooling medium loose efficiency for every meter it travel from the outdoor to the indoor unit and the pump works harder. The end result is not necessarily a loss in cooling inside but higher electricityconsumption.
Regards, Tintin.
tintin
 
Posts: 19
Joined: Sat Jun 03, 2006 4:13 am

Postby The Dude » Thu Nov 29, 2007 9:22 am

This is a very interesting thread. A refrigeration system is a closed loop system . So no more energy will be spent weather the "Line Set" is vertical or horizontal or a combination of both.However if the system is vertical you must have an inverted p-trap installed every 12ft of rise. Also pipe sizing is critical when running a line set due to velocity pressure for oil return and system refrigeration charge. Their are more factors involved for an efficient system. But I do not have the patience to put it all down at this time. My observance to air conditioning and refrigeration systems in LOS leads me to believe that most installers and repairmen haven't a clue why they do what they do to make a system operate. This is why the frustrations set in with many farangs in thailand.
The Dude
 
Posts: 12
Joined: Fri Dec 15, 2006 4:09 am

Postby Nawty » Thu Nov 29, 2007 10:26 am

What's an 'inverted P trap' exactly ??

So 2 examples here...

A single house, where the piping is running a horizontal distance of say 10 to 20m with maybe a vertical distance difference of 1 or 2 meters....should this have any performance loss over and above the recommended max distance of say 5 or 6 metres.

Secondly... A condo development of 8 levels, with all the systems placed equally half on the roof and half on the ground levels....so then the max distance should be about 11 or 12 meters vertically and whatever required horizontally.....how would this effect the performance ?
User avatar
Nawty
 
Posts: 804
Joined: Mon May 07, 2007 12:23 pm

Postby John Thede » Fri May 16, 2008 12:07 am

HI.

There are 2 different ways to provide active cooling.
1 is to circulate the cooling gas in the system.
1 is to circulate cooled water.

When circulating Freon - Ammonia - what ever or even CO2 ???,
then the media is pumped forward as liquid, expanded in the cooling unit,
and sucked back to the compressor as steam.
The longer the suction line is, the pressure drop increase.
To avoid this problem, the suction line must be over dimensioned
if the distance is too long.
Its the pressure drop in the suction line, that creates a too high diffence pressure over the compressor, and then the efficiency drops radical
over the compressor.
As it íis normally a hermetical compressor with a short piston movement
lenght, and a real primitive valve construction.
So... its not build to too high difference pressures.

Use cooled water instead. its a lot more eco friendly and then the amount off cooling media, and the risk of loosing it into the atmosphere is a lot lower.
John Thede
 
Posts: 2
Joined: Thu May 15, 2008 11:53 pm

Re: AirCon loss of performance per meter

Postby 39fiat » Thu Apr 23, 2009 8:35 am

my house is raised 1 meter and vented all round , when i install the a/c units . if i put them under the house will it hurt the proformance of the vented soffits? would i be better off with them out in the yard a bit further to avoid heat rising up into roof?
39fiat
 
Posts: 3
Joined: Sun Oct 26, 2008 11:46 am

Re: AirCon loss of performance per meter

Postby MGV12 » Thu Apr 23, 2009 10:24 am

39fiat wrote:my house is raised 1 meter and vented all round , when i install the a/c units . if i put them under the house will it hurt the proformance of the vented soffits? would i be better off with them out in the yard a bit further to avoid heat rising up into roof?


Positioning your air con heat exchangers in your crawl space will be better than on an external wall, where they would be directly under your vented soffits, if your location has a constant lee side and you can duct the heat out in that direction; even then make sure the outlet is past your soffit overhang to account for the days when there is no wind. If there is no constant lee side then a remote location would be better. Cool air shrinks and hot air expands and so hot air, like water and bugs, will always search for a way to get into your house. Hope your build goes well.

“Some days I am an optimistic pessimist ... other days I am a pessimistic optimist”
User avatar
MGV12
 
Posts: 5350
Joined: Wed Jan 23, 2008 4:23 pm
Location: Chiang Mai

Re: AirCon loss of performance per meter

Postby Nawty » Mon Nov 09, 2009 10:33 am

Not to mention cooler under there so the system should work a lot less harder and help cut your lecky bill.

Nice for the environment....well maybe not cos someone else will probably just do something to waste it again....
conwood is not real wood.....break it down 'con' to deceive...'wood'
User avatar
Nawty
 
Posts: 804
Joined: Mon May 07, 2007 12:23 pm

Next

Return to cooling systems

Who is online

Users browsing this forum: No registered users and 1 guest

cron