Page 3 of 4 FirstFirst 1234 LastLast
Results 27 to 39 of 42
  1. #27
    Join Date
    Dec 2005
    Location
    Cincinnati, Oh
    Posts
    6,461
    Post Likes
    Anyone else waiting for the day when units come shipped with a bottle of refrigerant, and it autofills?
    'unit low on charge. Click here to refill to correct charge.'
    *5 hours later*
    "Yeah ma'm, it was a hard one to figure out. But I got it lick'd."
    "Better tell the sandman to stay away, because we're gonna be workin on this one all night."

    "Dude, you need more than 2 wires to a condenser to run a 2 stage heatpump."

    "Just get it done son."

    Dad adjusted

  2. #28
    Join Date
    Oct 2010
    Location
    SW Michigan, near Battle Creek
    Posts
    921
    Post Likes
    Quote Originally Posted by TriWorksInc View Post
    Wouldn't a fan cycle control do the same thing but a little more efficiently ?
    yeah, but you have to explain "you need this $200 control to make it run as good as it did before I fixed it". and you get the calls about the "outside fan not running right.

    And I guess at 80F outside air tempature the overcharged system is a bit more efficient (more subcooling). a different story at 95F oat.

  3. #29
    Join Date
    Apr 2011
    Location
    Coastal Maine
    Posts
    1,092
    Post Likes
    I have to agree with Fearless on this one. Here on the coast of Maine we also deal with cooler temps and high humidity. We have to do about a 10 - 15% overcharge to orifice systems to achieve desired interior comfort.

  4. #30
    Join Date
    Jan 2008
    Location
    In the work truck
    Posts
    3,183
    Post Likes
    Quote Originally Posted by hvacvegas View Post
    Anyone else waiting for the day when units come shipped with a bottle of refrigerant, and it autofills?
    'unit low on charge. Click here to refill to correct charge.'
    *5 hours later*
    "Yeah ma'm, it was a hard one to figure out. But I got it lick'd."
    I hate to be the one to break it to you but Trane/ AM. Standard already do this!!

    Hook up a jug to the condenser, Push a button and walk away for an hour. Come back and you got it lick'd

  5. #31
    Join Date
    Sep 2008
    Location
    Western PA
    Posts
    26,675
    Post Likes
    Quote Originally Posted by Pascone10 View Post
    I hate to be the one to break it to you but Trane/ AM. Standard already do this!!

    Hook up a jug to the condenser, Push a button and walk away for an hour. Come back and you got it lick'd
    It takes an HOUR?

  6. #32
    Join Date
    Jul 2007
    Location
    Chicagoland
    Posts
    482
    Post Likes
    Quote Originally Posted by fearlessfurnace View Post
    guilty secret. Fixed orifice systems work better around here if slightly overcharged.

    The book is the same in New Mexico or Alaska. In Michigans low temp and high humidity I have gotten more than one call back because the system "doesnt cool as well" after I reduced the charge to the book. Add a 10-20% overcharge back in everybodys happy.
    The likelihood is, by overcharging a fixed orifice system you are reducing the system capacity causing longer run times and condensing more humidity right? So the real issue is probably system size and design, not some strange Michigan charging warp.

  7. #33
    Join Date
    Jan 2008
    Location
    In the work truck
    Posts
    3,183
    Post Likes
    Quote Originally Posted by jpsmith1cm View Post
    It takes an HOUR?
    To be honest I never actually did it that way. I installed one system and it was too cold to use that feature. The ambient has to be above 55 I think.

    YOu install and solenoid valve and it opens and closes it to add the refrigerant. In the manual I believe it said it allows the system to stabilize a while before continuing to add. So depending on how low it is you may be waiting awhile. Ill look for a manual but i don't have access to comfort site.

  8. #34
    Join Date
    Dec 2005
    Location
    Cincinnati, Oh
    Posts
    6,461
    Post Likes
    Quote Originally Posted by Pascone10 View Post
    I hate to be the one to break it to you but Trane/ AM. Standard already do this!!

    Hook up a jug to the condenser, Push a button and walk away for an hour. Come back and you got it lick'd
    http://www.youtube.com/watch?v=B_Qc_nmSUGQ

    replace daycare with service tech.


    Trane tech is getting wild. Push button charging.......

    thats freaking scary, and yet, I'm somehow aroused by this idea.....
    "Better tell the sandman to stay away, because we're gonna be workin on this one all night."

    "Dude, you need more than 2 wires to a condenser to run a 2 stage heatpump."

    "Just get it done son."

    Dad adjusted

  9. #35
    Join Date
    Feb 2010
    Location
    Northeast, PA
    Posts
    233
    Post Likes

    Fan cycling control

    Quote Originally Posted by fearlessfurnace View Post
    yeah, but you have to explain "you need this $200 control to make it run as good as it did before I fixed it". and you get the calls about the "outside fan not running right.

    And I guess at 80F outside air tempature the overcharged system is a bit more efficient (more subcooling). a different story at 95F oat.

    For an affordable $$.$$ solution I use the "p" encapsulated fan cycling pressure switch. I also try to explain the fan turning on and off to the customer, but you guys know how that can be.

  10. #36
    Join Date
    Dec 2016
    Location
    East Meadow, N.Y.
    Posts
    85
    Post Likes
    Quote Originally Posted by seanhoang View Post
    I respect "the man" alot and his knowledge of the trade. Perhaps he's been doing this for a long time that he "feels" thing. I know.. I know.. I'm confused myself. Me and him don't see eye to eye on everything, but he's passion about teaching me the trade.

    Well nuff' said. Thanks and see you guys on the other side!!!
    R-410A will force you to do it by the book at some point. R-22 is more forgiving but there were a few R-22 systems over the years, that did not conform at all to the way we do it, when we know the units we are working on, and the approximate indoor, and outdoor temps.

    You would be surprised at how many systems are not ready to perform for three days of 95+ heat. Either over or under charged. Created a monster here and there myself over the years.

    Sincerely,

    William McCormick

  11. #37
    Join Date
    Dec 2016
    Location
    East Meadow, N.Y.
    Posts
    85
    Post Likes
    Quote Originally Posted by TriWorksInc View Post
    Hey, for 21 yrs I have heard to charge an R-22 system to 30 deg above ambient temperature on the dishcharge gauge, guess what it did work on the old systems (I use superheat or manufacturers charging chart) and after charging a system sometimes it would match up. But now you get into the high efficiency systems and there not even close sometimes, I remove refrigerant from systems all the time to get the superheat. So the moral of the story is learn the proper way now and it will save you and customers alot of compressor failures. You will be amazed how fast you will get used to it, and you will never hook up to a system without checking the superheat and subcooling. It will make you a better technician.
    I agree, I will not setup a new R-410A system now without checking the sub-cooling. It is so easy to overcharge, nothing like R-22.

    Sincerely,

    William McCormick

  12. #38
    Join Date
    Feb 2010
    Location
    In a boiler room
    Posts
    7,736
    Post Likes
    Quote Originally Posted by Bill mcC View Post
    I agree, I will not setup a new R-410A system now without checking the sub-cooling. It is so easy to overcharge, nothing like R-22.

    Sincerely,

    William McCormick
    You're replying to 5 year old posts, how deep are you digging for these ancient posts.
    Worry is a really gross misuse of one's imagination. -- PHM

  13. #39
    Join Date
    Dec 2016
    Location
    East Meadow, N.Y.
    Posts
    85
    Post Likes
    Quote Originally Posted by Ford3517 View Post
    In school we were not even taught the method the OP posted. The only time my teacher and I charge any different than the manual states is when we use Enviro Safe. Then we charge by the refrigerant manufacturers instructions. I know efficiency changes everything, in school we learned (if my memory is correct) that condenser split should be around 30 if the SEER is below 5, 20 between 5 and 9, and 10 if above 9 SEER. I may be off on the numbers a bit but I do know one rule of thumb does not work for everything all the time so I take the time to do it right. I am just starting out so I want to do everything the right way and build a reputation so I don't take short cuts unless my teacher says so (he is in charge).
    Half the problem is that so many systems are plenum supply now with flexible duct. So much of the install work is putting in a new system to an old plenum box connected to flexible duct. There is a huge difference between that, and a system that has a diminishing trunk. And expanded take-offs within a few feet of the registers, that are all sized properly. You can get some strange things happening on one setup and not the other. My mentor always when in doubt, got out the cardboard. Then there is no doubt. I even throw away sub-cooling based on the cardboard test, or actual observed incidents.

    You can hear some funky sounds from a systems reversing valve, that has good sub-cooling in second stage, while it is running on a roof or on blacktop in first stage on an extremely hot day.

    I go by sub cooling for R-410A but will sometimes back off by a degree when the condenser is on a roof or a black surface.

    Add a zone damper system into the mix and again things change.

    Sincerely,

    William McCormick

Page 3 of 4 FirstFirst 1234 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Related Forums

Plumbing Talks | Contractor MagazineThe place where Electrical professionals meet.
Comfortech 365