AC Coolant Line Loops

[Mike Lamb]

The far AC unit in the photo (5 ton, I believe) makes 5 u-turns under this deck before it heads up the wall to the 3rd floor. What's the reason?

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[Mark P]

It provides the crack heads with more copper, but someone else may have another take on it.

[Mike Lamb]

I asked this on an HVAC forum and came up with not much.

A way to cool the deck above it?

AC was oversized and the outside air will add to the load to reduce oversizing problems? (the old line was cut out and replaced with this configuration.)

It was a novice and they were using one of those computer screen saver endless piping things as a template?

And, yes, more copper for crack heads to steal.

[Bain]

The coils seem superfluous to me. The system is pressurized, so additional right angles shouldn't have any effect on performance.

[Brian G]

Originally posted by Bain

The coils seem superfluous to me.

Yeah, and unnecessary too. [^]

I've not seen anything like that in all my travels....bizzaro. I'd love to know what the thought process was on that one.

Brian G.

Assuming There Was One...... []

[AHI in AR]

I can think of a few potential reasons:

1. Cost plus job.

2. Job pretty well finished at 3 pm Friday. Didn't want to get back to the shop too early -- and possibly be given a new task -- so adding a little footage of line seemed like a good way to kill time.

3. Just to see if anyone would notice it. Possibly even admire the artful configuration.

4. 3-Beer lunch made it seem like a good idea at the time.

I'm sure there are others...[]

[Scottpat]

Somewhere in the cobwebs of my brain I recall hearing that some HVAC guys think that the extra loops help the system in some way. I have seen lines coiled at an attic mounted unit a few times, when I worked in Mississippi.

Somebody had to do that with a purpose in mind as that took a good amount of time!

[JEuriech]

The air conditioning length of tubing and or number of elbows determine the size of the piping. Example: Thermo Pride Model AC13241A1 calls for 3/4" tubing suction line on 0-50" total length. For 50-75 length it is 7/8" and for 75-100' it is 1 1/8".

With all the excessive tubing being used, I would not think that you could get the full air conditioning rating from that system. It would not run efficiently plus you would need additional refrigerant.

Jeff Euriech

Peoria Arizona

http://www.thermopride.com/Manuals/13_SEERAC_I&O.pdf

[inspector57]

NO valid reason I can think of, but they may have been trying to reduce the potential for liquid return to the compressor (slugging) or reducing the tonnage of the system by absorbing some extra heat before the suction line got to the compressor.

Either of those theoretical remedies won't hold water in real life though and the desired results could be more easily (and more cheaply) accomplished with a suction line accumulator and a epr valve, respectively.

Just a waste of copper that does neither harm nor good at this point apart from a small amount of energy loss to the insulated lines.

[msteger]

No idea here either. I would think it would lower the efficiency of the system. I was always under the impression that the refrigerant lines should be as short as possible.

Maybe the HVAC tech forgot to bring a tool to cut the copper tubing to size, so he simply installed the entire length he had... just kidding.

[Neal Lewis]

Mike, did you say that system is 6 tons??

[Mike Lamb]

Yes, I did. My mistake. The units were 4 and 5 ton. I'll change my original post.

[Scottpat]

Originally posted by Mike Lamb

Yes, I did. My mistake. The units were 4 and 5 ton. I'll change my original post.

Mike, that might make for a good cartoon!

[Bill Kibbel]

The junior installer picked up the wrong lengths of pre-charged linesets with quick-connect fittings???

[Mike Lamb]

Originally posted by Scottpat

Originally posted by Mike Lamb

Yes, I did. My mistake. The units were 4 and 5 ton. I'll change my original post.

Mike, that might make for a good cartoon!

Yes, it would. Dave Argabright suggested this same thing to me a while ago, only with a plumber who charges by the fitting.

I havn't drawn anything in a while.

[Thor]

I've been in the HVAC industry for 37 years and that is just dumb.

Each one of the suction elbows is equivalent to almost 8' of straight line lenght ( 7/8"short radius 90 degree ells = 7.8' each). 20 ells = 160 ft equivalent length line set (just in the ells).

Also there should be a min 4' above units for air discharge.

[Mike Lamb]

Originally posted by Thor

I've been in the HVAC industry for 37 years and that is just dumb.

Each one of the suction elbows is equivalent to almost 8' of straight line lenght ( 7/8"short radius 90 degree ells = 7.8' each). 20 ells = 160 ft equivalent length line set (just in the ells).

Also there should be a min 4' above units for air discharge.

Thor, is 4' above an industry standard or just a certain manufacturer's specs? How much room side-to-side? Do you have any references? I've heard stuff about 12 - 16" on all sides but I just don't know.

[Thor]

I just pulled info on a couple of Trane Cond units and what they say for that model is 5' above unit and should be a min 12" from walls and all surrounding shrubbery on 2 sides and 2 sides unrestricted

( whatever that means). I have always used 4' min above with 1 side min 12" and other sides min 3'. Each system will have minor differences.

[Brandon Whitmore]

I have seen manufacturer's with minimums down to 8" from the wall (8 and 10" this last week).........

[Billy_Bob]

Hummm....

Maybe "deck" is the answer? Melt snow on the deck somehow?

Is it a heat pump-A/C?

Or sometimes you have situations like with large computer rooms where there is a lot of heat generated even in the winter and you need to have the A/C on even though it is very cold outside. Did A/C this go to some area which needed cooling year round?

[hausdok]

Hi,

Well, in the week that it's been discussed, he could have tracked down the installer and got it from the horse's mouth a hundred times. That's what I typically try to do when I have a puzzle like that; find out who installed it, look 'em up in the phone book or google 'em, and then I contact 'em directly, tell 'em who I am and why I'm calling and give 'em the address. Most folks are very cooperative and happy to tell me all about why they did what.

ONE TEAM - ONE FIGHT!!!

Mike