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  1. #1
    Join Date
    Jul 2007
    Location
    tampa
    Posts
    12

    where do i go from here?

    just joined site - awaiting approval for pro forums. Anyways here are the measurements from 2:00 PM today (my own house). bryant s/c 3.5 ton 5 yrs old --inside furnace model# 373LAV048095 with evap coil model#CK3BX042021AAAA no txv

    out temp-85 indoor DB-74 RH-60%
    suction line temp 41 guage reading-58PSI/32 deg
    liq. line temp 91 guage reading- 230PSI/ 111deg.

    Just removed wall surrounding condensor that was affecting airflow to condenser considerably. House is 5 yrs old I have lived here 3 months.
    Assuming house is ducted correctly (I admit that is a LARGE assumption) is my unit working at 100% efficiency?

    CONCERNS
    1- 18X30 return sufficient for 373LAV048095 ??
    2- 042 evap coil on 048 furnace and 042 s/c condenser.
    3- used superheat for charging and other measurements are way off!!
    4-checked blower and coil both clean
    5- girlfriend has had $300- $350 power bills for 5 yrs. and water heater and laundry are both gas powered
    Last edited by rsdipesa; 07-22-2007 at 03:20 PM.

  2. #2
    Join Date
    Nov 2000
    Location
    Eastern PA
    Posts
    68,945
    You have not requested pro status and do not have enough posts to do so. Until you have pro status and can post in pro-technical sections of the site, no specific answers to technical questions can be posted.

    It would at least be of some help if you put something in your profile that allows other users to know your professional status a bit better. Until pro status has been determined, you will be viewed as a DIYer so get those post counts up and let us know a little bit about you.
    Government is a disease...
    ...masquerading as its own cure…
    Ecclesiastes 10:2 NIV


  3. #3
    Join Date
    Jun 2003
    Location
    Florida
    Posts
    9,548
    You need a service call, as there's no way it's correct with a 32 degree coil temp. Sorry to be blunt, but if you don't know this you need to step away from the system and call someone that does.
    If everything was always done "by the book"....the book would never change.

  4. #4
    Join Date
    Jul 2007
    Location
    tampa
    Posts
    12
    Thanks for taking the time to respond. Sorry I don't know the ways of the site. However, I am always trying to discuss new ac topics at work and learn a trick to make my work day easier. I'm sure with a little guidance I will be participating in the forums in no time. I edited my profile and sent my email to the committee. Any tips on what else I can do to ensure a smooth entrance to the site?

  5. #5
    Join Date
    Aug 2003
    Location
    Fort Worth, TX
    Posts
    11,350
    Quote Originally Posted by rsdipesa View Post
    just joined site - awaiting approval for pro forums. Anyways here are the measurements from 2:00 PM today (my own house). bryant s/c 3.5 ton 5 yrs old --inside furnace model# 373LAV048095 with evap coil model#CK3BX042021AAAA no txv

    out temp-85 indoor DB-74 RH-60%
    suction line temp 41 guage reading-58PSI/32 deg
    liq. line temp 91 guage reading- 230PSI/ 111deg.

    Just removed wall surrounding condensor that was affecting airflow to condenser considerably. House is 5 yrs old I have lived here 3 months.
    Assuming house is ducted correctly (I admit that is a LARGE assumption) is my unit working at 100% efficiency?

    CONCERNS
    1- 18X30 return sufficient for 373LAV048095 ??
    2- 042 evap coil on 048 furnace and 042 s/c condenser.
    3- used superheat for charging and other measurements are way off!!
    4-checked blower and coil both clean
    5- girlfriend has had $300- $350 power bills for 5 yrs. and water heater and laundry are both gas powered
    I read your profile. If you got twenty years in, perhaps you're just getting your feet wet with learning about superheat and subcooling. And about airflow. Lots of guys out there been doin' the same old thing for years...so their twenty years or so may translate to one year experience repeated twenty times. I've been in the trade awhile but the last few years I've really accelerated the learning curve...the trade is changing constantly and the old school ways can leave one in the dust at times.

    That being said, you're running 20 degrees subcooling and 9 degrees superheat. Your indoor conditions are a bit on the humid side with 74 degrees at 60% relative humidity. That's a 64 degree wet bulb. Indoor wet bulb would be better at 62 or lower. As for why the humidity is running higher in the house than it should, you'll have to go through the system to find out why. Duct leakage, house infiltration, overcharge, too much airflow...a few things to mull over, yes?

    As for the high bills, your girlfriend may be having prolonged "personal summers" and she's running the crap out of an a/c system that can't get into her comfort zone. Since you mentioned you've messed with the charge on this system, keep in mind fixed orifice (piston) systems are critical charge. It doesn't take a lot of refer either way to kill the sensible and latent capacities of these systems.

    As for forum decorum, since you're new here, spend more time reading and less posting until you get a good feel for the site. That's not a slam, it's just good protocol when joining a new board. There is TONS of good info here in the various sections concerning HVAC technical matters, so if you're into that, you're in the right place. It takes awhile to find your "spot" on a participatory board such as this, but once you do, it's all good.
    • Electricity makes refrigeration happen.
    • Refrigeration makes the HVAC psychrometric process happen.
    • HVAC pyschrometrics is what makes indoor human comfort happen...IF the ducts AND the building envelope cooperate.


    A building is NOT beautiful unless it is also comfortable.

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