Thursday, May 14, 2015

HVACs with crossed cold/hot water lines versus condensate drainage

I’ll call this post “The Adventures of Installing New HVACs.”

Last night’s post on “HVAC Condensate Problems,” generated a number of emails to me as comments, requests, or questions.

MARK’S INTRO

I referred this set of questions from Mark Day to David Robinson. What was going on in Mark’s tier turned out to be caused by noonstandard installation of an HVAC done several years back.  Here is the intro by Mark and the Q & A exchange between Mark and David:

Last Friday, a Quality Air guy - Oleg - turned off our new console unit because he found condensation on the warm water line & thought our cold & hot lines could be crossed. The big problem was that hot water was bleeding into the chiller for the whole riser. 

I was sure the problem was not in our new carefully installed unit. And after closing our valves, the problem in the whole tier continued so…seems not [caused by Mark’s console HVAC]. 

But the console is still off & we can't cool our study. Oleg said a couple of days ago when I saw him in hall that they were still checking & hadn't found the crossed lines.

Talking to Hollis in the elevator, he outlined the clogged drains issue you [Karren Alenier] discussed.

So maybe the problem really is clogged lines? Or both that & crossed lines? 

MAIN QUESTIONS: 
1) Have you heard about the crossed lines issue?
David: Yes, I am familiar with it.

2) Have other apts. had their units' valves shut off?
David: My understanding is that all of the apts. in your tier will be shut off and brought back on line one at a time until the fan coil with the crossed lines is identified.  This is normal procedure.

3) When will we know that our risers/tiers lines have been cleared & we can safely run our HVACs?
David: Management will notify you.  Of course when the misconnected fan coil is identified the four pipes will need to be drained and the fan coil connected correctly.  Since Quality Air is already in the building the work should be completed rapidly.

4) You mention five lines have been cleared: out of how many total that need to be cleared?
David: The five lines were selected based on the number of condensate pans overflowing in the tier. The original plumbing blueprints for the building are being studied to determine the total number of condensate drains.  I suspect that they all need to be cleared.

5) Do they have a schedule as they did with windows so we'll know when ours is done?
David: When the total number of drains is determined a schedule will be developed and distributed.

FOLLOW UP

David told me that there were six engineers working on the problems in the building today along with some Quality Air employees. Here is the finding and fix as described by David:

“The offending unit turned out be a two pipe unit installed perhaps as long as 4 years ago and jury-rigged to connect to the 4 pipe riser.  It is currently isolated from the system and will be replaced with the appropriate 4-pipe unit by Quality Air early next week.  Having been installed years ago, the history on who had installed it is lost.”

David also said, “In the separate issue of clearing condensate lines, the engineering staff working with Denzel continues to remove the blockage from additional lines.  They have been too busy to review the blue prints so no total number of lines is yet available.” [The number of lines is not equal to the number of tiers in our building, Typically, more than one tier feeds into these condensate lines.]

Also one other thing to know about the floods (dripping) from the condensate lines is that these wet ceilings/walls are more likely to happen on the lower floors.

Thank you, David Robinson, for volunteering your time to sort out these problems with the army  of engineers.


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