Results 1 to 13 of 13
  1. #1

    Off line Chiller problems

    I am currently looking into adding a VFD to one chiller in my 3 chiller plant (3 750 TRANE 1984 Chillers). I plan to make that chiller the lead one. Since the other chiller will serve as a backup only, they will be off line most of the time.

    What problems can arise from having chillers off line? I know one problem is air infiltration and refrigerant leakage, but I found a company that claim it can solve this problem by recirculating hot water thus raising the regrigerant pressure to Atmospheric Pressure. It's called prevac Aquapower, did anyone here ever used it?

    Thanks Gil

  2. #2
    Join Date
    Dec 2004
    Location
    Central New York
    Posts
    70
    I have installed these on many chillers. I have even rigged up a portable version that I can hook-up to any chiller for leak testing purposes. They have an adjustable setpoint for vessel pressure. An onboard pump circulates water through a small electric hot water heater and through the chiller, A tranducer on the chiller monitors pressure and cycles the electric heater on/off as needed. We have many customers that use them for the exact same purpose as you intend to.

  3. #3
    Join Date
    Aug 2006
    Location
    Mixing oil and fire with a big spoon.
    Posts
    4,336
    Quote Originally Posted by trane_stud View Post
    I have installed these on many chillers. I have even rigged up a portable version that I can hook-up to any chiller for leak testing purposes. They have an adjustable setpoint for vessel pressure. An onboard pump circulates water through a small electric hot water heater and through the chiller, A tranducer on the chiller monitors pressure and cycles the electric heater on/off as needed. We have many customers that use them for the exact same purpose as you intend to.
    me too! i really like them. makes small repairs (like vane operator rebuilds) very simple and easy and fast. be careful about cold air currents (like the kinds that can happen in a boiler plant) moving over the chiller. also, you need to be able to shut off the chilled and condensor water flow like with an isolation valve or shut the pumps off if they are dedicated.

    i have a customer (that i will seeing tomorrow as a matter of coincidence ) who has one of the old style "blanket" heaters. i show him the leaks every year...same leaks too. but the purge only puts on 10-20 minutes a year and we have never added refrigerant to it. works great but i can't get any leak repair work out of him, lol!
    "Mother" is the name for God on the lips and hearts of children....The Crow

  4. #4
    Join Date
    Jan 2004
    Posts
    1,174
    I gotta disagree, the blankets IMO are the biggest waste of time and money going, I can't imagine anyone wanting to pay for a resistive heater being on for 1/2 the year when it is much easier to keep the chiller tight. Not only that but refrigerant replacement will also add to the cost. A total bad ideal in my mind, and I have looked after a few that Carrier put on, but I guess it was because there purges were no good.
    Federal Reserve, stealing your kids futures since 1913

    UA290

  5. #5
    Join Date
    Aug 2006
    Location
    Mixing oil and fire with a big spoon.
    Posts
    4,336
    Quote Originally Posted by acjourneyman View Post
    I gotta disagree, the blankets IMO are the biggest waste of time and money going, I can't imagine anyone wanting to pay for a resistive heater being on for 1/2 the year when it is much easier to keep the chiller tight. Not only that but refrigerant replacement will also add to the cost. A total bad ideal in my mind, and I have looked after a few that Carrier put on, but I guess it was because there purges were no good.
    the one i am working on stuck on originally and they replaced it. been working well ever since. i do not think that they offer it any longer.

    i do have to agree that a tight chiller is a better alternative, but sometimes a small leak way back from the suction elbow may not be cost effective to repair.
    "Mother" is the name for God on the lips and hearts of children....The Crow

  6. #6
    Join Date
    Jan 2004
    Posts
    1,174
    A small leak is cheaper to repair than running a new circuit, installing blankets and paying for electricity, especiall when the crap and trade bill raises it to 50 cents a kwhour.
    Federal Reserve, stealing your kids futures since 1913

    UA290

  7. #7
    Join Date
    May 2001
    Location
    Western Wa
    Posts
    1,832
    That's "crap on trade" which is what the agenda truly is.
    God Bless our Veterans

    God Bless the USA

  8. #8
    Join Date
    Sep 2008
    Location
    Delaware
    Posts
    243
    Have used the"Prevac" systems since they hit the market a (few) yrs ago. Initial cost is a factor but lifetime savings should be considered. Do you do an annual leak check? How many hrs to set up and pressurize a machine? As mentioned, small leaks can be found and repaired at lower cost. The unit may be energized for 1/2 the year but only consuming power when the pressure drops below setoint and heat is needed( blanket type). I did not care for them at first either but found them to be benificial.

  9. #9
    Join Date
    Jan 2004
    Posts
    1,174
    I don't leak check a chiller if it has a Trane Purifier on it, they are leak check devices in themselves.If it doesn't have a trane purge at first, it usually will within a year or two, no matter who's chiller it is.
    Federal Reserve, stealing your kids futures since 1913

    UA290

  10. #10
    Join Date
    Jan 2008
    Location
    windy city
    Posts
    4,430
    installed plenty of the prevac 'blankets' back in the early/mid 90's. a filthy job it was! all are now kaput.replacement are the prevac 'mini boilers'. the few i've installed work great on 11.

  11. #11
    Join Date
    Nov 2007
    Location
    I am unsure myself
    Posts
    1,116
    Quote Originally Posted by acjourneyman View Post
    I don't leak check a chiller if it has a Trane Purifier on it, they are leak check devices in themselves.If it doesn't have a trane purge at first, it usually will within a year or two, no matter who's chiller it is.
    Hey AC got a bad UPCM word has it you installed 12 yrs ago I want warranty ha. Or maybe you have been dialing in and messing with me either way I want it fixed.

  12. #12
    Join Date
    Dec 2005
    Location
    Rockhill South Carolina
    Posts
    370
    134a dont need no damn heater.

  13. #13
    Join Date
    Jan 2004
    Posts
    1,174
    134a dont need no damn heater.
    , no just needs to be buried in dry ice to keep refrigerant in. Hey Mustard, no warranty, I had to install those UPCM's on chillers under duress.They are the hokiest things put on a chiller ever, rip them off and put a proper chiller panel on there. I can't believe RH made us do that. M-I-C-K-E-Y M-O-U-S-E , I was just an apprentice so don't blame me ,LOL.
    Federal Reserve, stealing your kids futures since 1913

    UA290

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event