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  1. #1

    Worth Replacing older working HVAC now?

    I live in a 2 story 1800sq.ft. house built in 1987 in Southern California and it's getting pretty hot now and I'm getting tempted by the rebates being offered ($1700.00).

    I still have the original HVAC system which seems to be working fine (or the same as it has since I moved in 9 years ago) which is as follows
    Lennox Conservator III
    Lennox HS18-511-3P (4 ton 3 phase?)

    I've had it serviced less than a year ago and am very good with the filters as well. Even my energy bills aren't that much, just under $200/mo for both electrical and gas.

    My biggest complaint, which I hear a lot, is how difficult it is to cool rooms upstairs. The only way to get it under 80 is to close all the down stairs vents and set it to about 72 and it still takes 2+ hours and that's in the evening. I've also taken a quick at the ducts which seem fine.

    Sounds like if I was to replace it this may be a good time but would it be mostly a waste? I know it won't pay for itself anytime soon but would the newer units make a big difference in comfort especially upstairs without running all day? I also don't want to do a major upgrade price wise just a newer possibly slightly higher level system.

    Thanks!

  2. #2
    Join Date
    Mar 2005
    Location
    Houston, Texas
    Posts
    11,829
    To fix the problem correctly,will involve a lot more than just changing old units for new.

  3. #3
    Join Date
    Jun 2007
    Location
    The Twilight Zone
    Posts
    2,964
    Quote Originally Posted by mtbjoe View Post
    I live in a 2 story 1800sq.ft. house built in 1987 in Southern California and it's getting pretty hot now and I'm getting tempted by the rebates being offered ($1700.00).

    I still have the original HVAC system which seems to be working fine (or the same as it has since I moved in 9 years ago) which is as follows
    Lennox Conservator III
    Lennox HS18-511-3P (4 ton 3 phase?)

    I've had it serviced less than a year ago and am very good with the filters as well. Even my energy bills aren't that much, just under $200/mo for both electrical and gas.

    My biggest complaint, which I hear a lot, is how difficult it is to cool rooms upstairs. The only way to get it under 80 is to close all the down stairs vents and set it to about 72 and it still takes 2+ hours and that's in the evening. I've also taken a quick at the ducts which seem fine.

    Sounds like if I was to replace it this may be a good time but would it be mostly a waste? I know it won't pay for itself anytime soon but would the newer units make a big difference in comfort especially upstairs without running all day? I also don't want to do a major upgrade price wise just a newer possibly slightly higher level system.

    Thanks!
    The problem with the upstairs not cooling may be duct related and/or needing additional insulation in the attic.

    The good thing about replacing the a/c now is that you are not in an emergency situation and have time to research your choices and get several competitive bids.

    2 years ago I replaced a fully functional 8 SEER 21 year old Trane heat pump with a new 14 SEER system. Maryland electric rates went up 60% thanks to de-regulation without competition. I combatted the 60% rate hike with a 40% gain in efficiency.

    Good luck.

  4. #4
    Join Date
    Apr 2001
    Location
    san jose,ca.
    Posts
    5,285
    when you get a hvac contractor out to your house ask him about a 2 zone system.
    one upstairs\ one downstairs.
    I have a 2000 sq,ft. ,two story & i always had a 10-14 deg temp difference.
    Now i have 1-2 deg. diff. between first & second floor.
    I`m in san jose,ca.

  5. #5
    Thank you very much! Agree about the ducts even though they seem OK after almost 25 years I'm sure there's some problem areas. I'm planning on taping, insulating or even replacing the upstairs ones in my attic.

    Bigbird, that sounds like exactly where I am now vs where I want to be. I was just looking at the 2 zone systems so I'll be asking about those for sure.

  6. #6
    Join Date
    Jul 2009
    Location
    Alabama
    Posts
    63
    You might want to consider an entire duct replacement especially if your duct has internal insulation. I like to use externally wrapped metal.

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