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Hi V system

"The air flow test out at 510 cfm and this is a 2 ton Lennox condensing unit. " you are moving insufficient air for a 2 ton system. You NEED 375-400 cfm / ton of in your case 750-800. You are way short.

The pressures you get despite your lack of air, tell me "Freon Freddy" is your mechanic,and adds refrigerant until you get the right low side read, but your sending some liquid back to the condenser, hence the lower temps after a few hours.

This is not a component problem..it is almost 100% guaranteed airflow related. Fix that, then get hte refrigerant level right. You should have no problems.

My $0.02



  • Andy_6
    Andy_6 Member Posts: 48

    I have a system that is a 2 ton Energy Saving Products Hi V system that has been having lots of troubles. They have sent me 4 new coils, replaced the line set 3 times, 4 new txv's and 1 new condensing unit. Also replaced the freon 2 times and now the factory wants to replace yet another condenser. I am begining to think that they don't know how to fix the problem. The smptoms are that on start up it will run at a coil temp of 42 degrees F, and a high side pressure before the txv of 175 psig. And the condensing unit is the same. The problem shows up after running for over 4 hours. The Coil temperature stays the same at 42 degrees but the suction line temperature at the condensing unit drops to 28 degrees and the head pressure goes very high. Sometimes to 375 psi. The freon test out dry and the lines blow free with nitrogen. Any ideas other than getting rid of Hi V? I almost forgot. The air flow test out at 510 cfm and this is a 2 ton Lennox condensing unit.
  • don_144
    don_144 Member Posts: 27

    I guess you can say they lost all their money on that project as well.But yet they keep trying to get it right.
    Kudos to them for that.

    It appears to me that your system does not have enough airflow across the coil and ever forgiving expansion valve
    thats doing its job.

    I would say look at your distribution system again and see if you have enough outlets.
  • tim smith
    tim smith Member Posts: 2,544
    Another problem besides airflow

    Airflow is definately a problem but thats not the cause of the high head pressure. If suction drops so will head.. Maybe non condensibles in system. Restriction on the inlet side of the expansion valve, possibly strainer plugged. Good luck, Tim.
  • Eugene Silberstein
    Eugene Silberstein Member Posts: 1,380

    Are you the Tim from HVCC?
  • Andy_6
    Andy_6 Member Posts: 48

    You all seem to be forgeting that this is a Hi V system much like a unico/spacepak that requires much lower cfm. About half that of conventional duct systems. The HiV specs out 500 cfm on a 2 ton condenser when matched with a Hi V. And No freon freddy was not on the job. If more freon was added it was by the recommendation of the manfactures not me or my service tech.
  • Mitch_4
    Mitch_4 Member Posts: 955
    My Apologies Andy

    I neglected to see that it was a hi V system. No slight on you or your techs..My error and I apologize.

    But I will still state that it is unlikely a component problem, other than a restriction like a poorly reamed joint, or copper shavings in the line.

    Heck I have even had an install (gas pipe) where the finish varnish on the inside stripped off and plugged the works.

    Keep us posted.

  • Andy_6
    Andy_6 Member Posts: 48

    We are going out tommorrow and replacing the Hi V system with unico. Every component in the refrigeration side has been checked and because it could only be a restriction it was then replaced. Still nothing seemed to help the situation. So I am going back to unico's. Have not had any troubles with them.
  • vtheat
    vtheat Member Posts: 8

    i see you are going back to unico ,very good idea. unico and spacepak are the only true hi-v systems out there to be installed
This discussion has been closed.