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HVAC workmanship question

Old 07-12-2015, 05:50 PM
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I am having a new telecom site built with 3 Mitsubishi inverter 3 ton out door units, 2 large air handlers off of two of the outdoor units, and 2 wall mount units as backup for the air handlers off the third.. Critical communication facility, with 100% reduandcy required

The contractor is rushing the job, too much rushing in my mind. They are trying to get us to accept the building ASAP.

Is it industry practice to run all of the cooling lines (40-50' one way) in soft flex? I would have thought that a permanent install would hard piped copper with soldered fittings where needed and properly supported. Obviously less fittings are needed and potential fail points with using soft flex, but it doesn't seem right.

Any thoughts?
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Old 07-12-2015, 06:52 PM
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Not necessarily bad, photos?
Typically there is a piping schematic.
Was it followed?
Shorter runs without significant differentials in height can sometimes take advantage of simplicity.
That being said, clean is clean. It's very difficult to run soft copper cleanly across an open area.
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Old 07-12-2015, 07:03 PM
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Originally Posted by Dan Hicks 2 View Post
Not necessarily bad, photos?
Typically there is a piping schematic.
Was it followed?
Shorter runs without significant differentials in height can sometimes take advantage of simplicity.
That being said, clean is clean. It's very difficult to run soft copper cleanly across an open area.
Pics in the morning, I was so disgusted at the state of the site, I had to leave. The GC is pushing way to hard, to the point that subs are getting pissed and cutting corners. The electricians were there 10 hours Saturday and Sunday.
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Old 07-12-2015, 07:17 PM
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If the line sets are white they are the new line sets used for the mini split systems.
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Old 07-12-2015, 07:38 PM
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I have never seen a mini split piped up with hard copper. The tubing size is not standard refrigeration copper and the units all come with specifically sized refrigeration grade soft copper.
It is absolutely standard in the HVAC industry and your contractor is not cutting corners in that regard.
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Old 07-12-2015, 07:53 PM
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Mitsu is quite happy with only soft tubing and flare connections, saves problems caused by poor brazing practices. That said, proper support, chafe protection, and routing are important.
There should be an HVAC piping spec page in the print set, with line sizes, hanger types, connection and start up procedures, that is what the contractor must follow.
I've only seen the new white line sets with 1/2 wall insulation, and some jobs are now requiring 3/4 wall thickness.
Maybe contact Mitsu or the supplier, the job might be worth a visit from a factory rep.
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Old 07-13-2015, 02:02 PM
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It is a complex deal, but I work for a governmental agency. My department is paying the bill, another is managing the project, who has contracted with an architect for construction management/design. Don't go there. It is F'ed up.

Here are the pictures. They plan to slide the metal siding behind a re-secure the HVAC lines. The siding is delayed.

I think they should have waited for the siding, drilled the holes at the top in a straight line, secure the lines better and in a straight line, use outdoor uni-strut and tucked the lines BEHIND the units instead of the goofy way they did it here. Way easy for a lawnmower to whack the lines.
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Old 07-13-2015, 02:48 PM
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There has to be a reason why it looks like ( They did not give a dam) ---------no pride in craftsmanship --------------pub-------------
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Old 07-13-2015, 03:46 PM
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Are those units too close to the wall? They need room for airflow. And yes ,those lines out front will get stepped on.
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Old 07-13-2015, 03:57 PM
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Originally Posted by hevysrf View Post
Are those units too close to the wall? They need room for airflow. And yes ,those lines out front will get stepped on.

I hope so... HVAC engineer/consultant approved the pad.

Pictures are circulating amongst consultants and such today. I was shocked yesterday when I checked on the job site yesterday afternoon. I was pretty disappointed in the work.
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Old 07-13-2015, 04:41 PM
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Wait till the sun has beat on that armaflex for a little while. They used no armaflex glue to hold the insulation together, so next option is duct tape which will come apart and look special in a year.

There is no reason for them not to use hard pipe for this installation other than cost. Soft copper is cheaper than stick and the labor to run stick versus soft is quite a bit more. The cheapest HVAC contractor got the job so you get what you pay for and nothing more.

I just looked at the pictures again and holy hell that is horrible.
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Old 07-13-2015, 05:03 PM
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That right there is "It'll work... and we don't care what it looks like". No pride. Shame.
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Old 07-13-2015, 05:11 PM
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I was just checking as I don't want to come off as a jerk. That is A LOT of money in HVAC, what you don't see is the $22k of City mandated DDC controls.
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Old 07-13-2015, 05:27 PM
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Is that where the fake chimney is going? Was there any kind of plan in place or were these meant to run down the center of the wall
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Old 07-13-2015, 05:46 PM
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That's not even good enough to be crappy. I think it's time for an ass-chewing meeting.
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Old 07-13-2015, 06:29 PM
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Originally Posted by Mine Now View Post
Is that where the fake chimney is going? Was there any kind of plan in place or were these meant to run down the center of the wall
It wasn't detailed on the plans to my satisfaction, but I wasn't too worried as it is an industrial building, but I sure didn't expect it zig zag down and then be at ground level to get whacked by a lawnmower. No there is no false chimney
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Old 07-13-2015, 06:34 PM
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You'll complain... they'll box it out in a chase and side it over...

Sloppy work hidden well. LOL... sounds like everyone these days.
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Old 07-13-2015, 06:39 PM
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low bidder is rarely the best choice
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Old 07-13-2015, 06:52 PM
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It looks like not enough clearance in rear of units. The linesets look awful.
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Old 07-13-2015, 07:20 PM
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Originally Posted by folly basser View Post
low bidder is rarely the best choice

Government-low bidder gets the job.
770sqft 1.5 million dollars. (Construction $1.2mil architect/pm $300k)
Most expensive site I have ever seen.
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