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  • Heat Pump Head Scratcher

    Here it is by the numbers:
    Outdoor Ambient: 108
    Indoor Ambient: 90

    New Install 16 SEER HeatPump Condenser with a matched upflow Fan Coil ( 24K BTU on 900 SQFT new construction)
    Evaporator(Temps taken@ inlet and outlet of evaporator line set via contact thermometer)
    Suction Temp: 74
    Discharge Temp: 110

    Condenser
    Discharge Pressure: 440 / 124 degrees
    Temp @ Discharge service valve: 109
    Suction Pressure: 178 PSI / 63 degrees
    Temp @ Suction service valve: 63 degrees

    Total Superheat: 14 degrees
    Subcooling: 15 degrees

    System is splitting about 6 degrees between the return and the supply air with these conditions.
    -I do not normally keep a sling psychrometer with me:-/

    -Is the system just maxed out due to the high ambient s thus the LOW evaporator split temperatures? I don't feel like the evaporator is loading enough.

    -My first thought was that I had scortched the TXV so I was not loading properly after the initial install ( I replaced the TXV Today and these are the current numbers).

    I have got myself chasing my tail...LOL

    -
    Last edited by OkieBill; 07-07-2011, 07:51 PM.

  • #2
    Re: Heat Pump Head Scratcher

    You have a huge hole in the ductwork. I'd check that 1st.

    Comment


    • #3
      Re: Heat Pump Head Scratcher

      Doesn't sound to far out of line with the ambient temps that you have. You do have heat transfer. It should get better once the indoor ambient drops below 80.

      Comment


      • #4
        Re: Heat Pump Head Scratcher

        Originally posted by TheMaster View Post
        You have a huge hole in the ductwork. I'd check that 1st.
        Good to see you are not BANNED anymore "The Master" welcome back

        Comment


        • #5
          Re: Heat Pump Head Scratcher

          Originally posted by OkieBill View Post
          Good to see you are not BANNED anymore "The Master" welcome back
          Yeha I was reading posts while I was on my vacation......nothing much was being talked about except how many tools Rick has and who's K-sissy isn't working. lol

          I also was reading about propress.....one guy claimed the sealing element aka "o" ring doesn't really make the seal.....the copper being pressed together is what seals it. Funny stuff.

          Comment


          • #6
            Re: Heat Pump Head Scratcher

            Originally posted by TheMaster View Post
            Yeha I was reading posts while I was on my vacation......nothing much was being talked about except how many tools Rick has and who's K-sissy isn't working. lol

            I also was reading about propress.....one guy claimed the sealing element aka "o" ring doesn't really make the seal.....the copper being pressed together is what seals it. Funny stuff.
            While I appreciate your constructive input in most threads. Your decision to come into one of my threads considering your past behavior and attempt to pass off your veiled insults as humor appears petty and childish.
            Last edited by OkieBill; 07-07-2011, 09:41 PM.

            Comment


            • #7
              Re: Heat Pump Head Scratcher

              Originally posted by OkieBill View Post
              While I appreciate your constructive input in most threads. Your decision to come into one of my threads considering your past behavior and attempt to pass off your veiled insults as humor appears petty and childish.
              It seemed to me the unit was working fine. So I suggested a hole in the duct work......and unless you have checked it....it might be one. But the other guy said its working fine so I would say he is right. Its just hot.

              Whats wrong?

              Whats my past behavior? Nothing was ever proven. Computers are not perfect. Example my friend in college just got accused of cheating on a computer science test because of an IP address. the professor claimed that the IP address was one of a previous student 4 years prior. It took 3 professors from two different colleges to figure out what happened. Sorry your unhappy. What can I say,let it go and put me on your ignore list.

              Oh and ever time I sign on to Ridgid forum I get popups from spyware and malware programs saying my cumputer is being accessed.

              The forum changed formats because it would be "More secure" was the answer that was given.

              IMO its not too secure.
              Last edited by TheMaster; 07-07-2011, 09:45 PM.

              Comment


              • #8
                Re: Heat Pump Head Scratcher

                What's your RLA reading on the compressor?

                "Condenser
                Discharge Pressure: 440 / 124 degrees
                Temp @ Discharge service valve: 109
                Suction Pressure: 178 PSI / 63 degrees
                Temp @ Suction service valve: 63 degrees"

                Is that suction service valve temp, 63F, a typo?

                That is 0F superheat and 15F subcooling. You could be overcharged. How long is lineset?
                You may also have too much airflow moving across the evaporator. To raise delta T, you can try lowering fan speed.
                http://www.hvactechgroup.com

                Comment


                • #9
                  Re: Heat Pump Head Scratcher

                  Originally posted by Tech X View Post
                  What's your RLA reading on the compressor?

                  "Condenser
                  Discharge Pressure: 440 / 124 degrees
                  Temp @ Discharge service valve: 109
                  Suction Pressure: 178 PSI / 63 degrees
                  Temp @ Suction service valve: 63 degrees"

                  Is that suction service valve temp, 63F, a typo?

                  That is 0F superheat and 15F subcooling. You could be overcharged. How long is lineset?
                  You may also have too much airflow moving across the evaporator. To raise delta T, you can try lowering fan speed.
                  Thanks for the reply TechX, I'm still fighting this system (it is kicking my a$$...lol)

                  Here is a more detailed look: (numbers are from earlier today after this system has run for 24 hours)
                  New Install: Carrier 410A 14 SEER 24K BTU Heat Pump w/ matched Fan coil installed in an 800 sqft hunting cabin (new construction).

                  90 degree ambient
                  152 suction Pressure
                  1.8 deg superheat (Temps taken close to service valves @ condenser I will take it @ TXV inlet tomorrow if we think that will help:-))

                  399 Discharge Pressure
                  15.2 deg Sub cooling (Temp taken close to service valve @ condenser Suction line)

                  The condenser lists 14 deg sub cooling

                  80 degree interior temperature and the evaporator is only splitting 8-10 degrees across the evaporator. The system will run constantly as it never catches up with the load.

                  A few things I have noticed:

                  - I'm running at what I believe a slight over charge by refrigerant weight

                  - When I installed this system on initial start-up I noticed the low delta across the evaporator but thought that it was due to the High ambient temp inside the cabin (109 degrees).

                  - My first thought was that I damaged the head on the txv as I had some scortch marks on it so I replaced it but on an install later in the week on the same size and type of equipment I found the same scortch marks on a new unit right from the factory... *shrug*

                  - My next WAG was that I had an obstruction in the system looking at my numbers. I pulled the filter dryer though I did not have any delta through it and compared it to a new one from the truck (blow through test:-)) the installed filter dryer acted like it was more restricted then a new one so I installed a new one.

                  -Inspected the line set for crimps (none found)

                  -Airflow set @ fan coil for 24K BTU

                  Comment


                  • #10
                    Re: Heat Pump Head Scratcher

                    Originally posted by OkieBill View Post
                    Thanks for the reply TechX, I'm still fighting this system (it is kicking my a$$...lol)

                    Here is a more detailed look: (numbers are from earlier today after this system has run for 24 hours)
                    New Install: Carrier 410A 14 SEER 24K BTU Heat Pump w/ matched Fan coil installed in an 800 sqft hunting cabin (new construction).

                    90 degree ambient
                    152 suction Pressure
                    1.8 deg superheat (Temps taken close to service valves @ condenser I will take it @ TXV inlet tomorrow if we think that will help:-))

                    399 Discharge Pressure
                    15.2 deg Sub cooling (Temp taken close to service valve @ condenser Suction line)

                    The condenser lists 14 deg sub cooling

                    80 degree interior temperature and the evaporator is only splitting 8-10 degrees across the evaporator. The system will run constantly as it never catches up with the load.

                    A few things I have noticed:

                    - I'm running at what I believe a slight over charge by refrigerant weight

                    - When I installed this system on initial start-up I noticed the low delta across the evaporator but thought that it was due to the High ambient temp inside the cabin (109 degrees).

                    - My first thought was that I damaged the head on the txv as I had some scortch marks on it so I replaced it but on an install later in the week on the same size and type of equipment I found the same scortch marks on a new unit right from the factory... *shrug*

                    - My next WAG was that I had an obstruction in the system looking at my numbers. I pulled the filter dryer though I did not have any delta through it and compared it to a new one from the truck (blow through test:-)) the installed filter dryer acted like it was more restricted then a new one so I installed a new one.

                    -Inspected the line set for crimps (none found)

                    -Airflow set @ fan coil for 24K BTU
                    Bill,

                    Your head pressure seems a little high for the ambient. I installed a 13SEER Bryant 2ton the other day.10 minutes after startup, head pressure @ 96 F ambient 385, suction 150, indoor temp 79F, liquid line temp 104.7F, comp. RLA 6.75.

                    James

                    Comment


                    • #11
                      Re: Heat Pump Head Scratcher

                      Well it looks like I did it to myself...
                      -5 kw electric heat strips were pulling in on a call for cooling thus the crappy Delta across the Evaporator
                      - In my zeal to improve my delta I was running a bit overcharged
                      -Control board set for 0-10KW CFM airflow in heating which push's an added 400 CFM across the evaporator in heating and in my case cooling so I was running to much airflow as well.

                      All I can do is shake my head.... The heat must be getting to me*shrug* Thanks for the help all :-)

                      Comment


                      • #12
                        Re: Heat Pump Head Scratcher

                        I had a similar deal, just a stuck sequencer, the pressures were on the money perfect outside. but my vapor line was coming back at 80 degrees. when it was only 75 outside. I finally pulled my head out and realized the heat was coming on every time it got a call for cool.
                        No, it's not rocket science, it's plumbing and unlike rocket science it requires a license.

                        Comment

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