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bingeo_gw

Gas to Oil conversion quote - input appreciated

bingeo
10 years ago

Converting from Oil to Gas furnace includes changing A/C and Water heater. Live in Maryland.
Existing Ac- 3.5 ton
2900 sq ft colonial (1000 sq on each floor and 900 sq ft of finished basement.
Change is based on increasing cost of Oil (80 AFUE furnace and 10 SEER ac -16 yrs old)
Existing problem with air flow: Two rooms on the upper level farthest from the furnace has most difficulty cooling and heating (differences between upper floors and the 2 rooms can range upto 10F if doors to room are closed - dampers checked - fine)
Have had 3 quotes - two have been discarded - overpriced 18K for a 80 AFUE furnace that can be vented to the existing b vent, second installer was pushing for a 4 ton ac with a 2 stage furnace providing 96 AFUE
Third company has an excellent reputation and has offered two options for Lennox systems
Evap coils (CX34-62 C) and Furnace (SLP98UH110VXV60C) are the same for the two options
AC options: 3.5 ton XC17-042 (EER 16.5, SEER 16.5) and XC14-041(EER 13, SEER 16)
Total cost of install for heating and cooling (no oil tank removal, no water heater install cost): 11.3K and 9.3K respectively
Have heard one HVAC installer during the estimate state that the current blower has 1500 cfm, although note sure where I can find this info.
Std warranty on equipment, 10 yr on labor with maintenance agreement
Questions:
Which ac is the best option?
Is a modulating furnace needed- would a 2 stage be sufficient?
Does changing to a variable speed blower furnace improve the problem with airflow in the two rooms?

Comments (6)

  • tigerdunes
    10 years ago

    Are you saying the difference between the quotes is the condenser model? If so, that's pure nonsense.

    What model thermostat?

    New lineset?

    New filter box?

    Dealer should recommend improvement to the two rooms that have temperature difference. Very common problem though. Obviously airflow is poor, not enough BTUs. How many returns upstairs? Don't expect any significant improvement to these rooms because of modulating or two stage furnaces. Usually this is ductwork related.

    Finished basement is below grade? I would think the 90 KBTU model furnace would be more than adequate. I would want to see supporting documentation to justify the 110 model. What size and eff is existing furnace?

    For information, the XC17 AC condenser configuration qualifies for fed tax credit, the XC 14 condenser does not.

    Finally, I would recommend getting a competitive quote from Carrier/Bryant for comparison.

    Post back.

    IMO

    This post was edited by tigerdunes on Mon, Nov 18, 13 at 8:14

  • bingeo
    Original Author
    10 years ago

    Tigerdunes,
    Thanks much for the input. In response to your questions:
    1) The difference in quotes is based on condenser diff only
    2) Thermostat: I-comfort Lennox
    3) New lineset - yes
    4) New filter - No. Approx 3 yrs ago, had 20x25x4 filter put in - Healthy Solutions Climate Model: HCC20-28. FYI: Quote offers Honeywell F-100 for about $400.00 additional cost and Aprilaire Humidifier Model #700 for $450.00 (debating humidifier install)
    5) Basement: all of it below grade
    6) Existing oil furnace: Input: 131K BTU/hr, 80AFUE (Tempstar Lincoln series, Model NUOD105BHA)
    7) Competitive quote from Carrier/Bryant in process, will let you know when I have it.
    8)XC-14-041 coupled with CX34 62C and SLP98UH110V60C gives a SEER of 16 (AHRI ref 4253822) - does that still preclude the fed tax credit?
    9) The evap coil is for a 5+ ton system, so it bothers me that this may not be matched to the 3.5 ton condenser and can damage the coil in the long run. However, Lennox tech document lists it as a match in the AHRI match listing. My understanding was the general rule of thumb is to keep the evap coil to no more than 1/2 ton in excess of the condenser's specs. Any thoughts?

  • bingeo
    Original Author
    10 years ago

    Tigerdunes,
    Also meant to add that there are three returns- one on each floor (incl basement) located on the hallway for the main and upper floor and smaller return in the basement.
    Thanks

  • bingeo
    Original Author
    10 years ago

    Tigerdunes,
    Also meant to add that there are three returns- one on each floor (incl basement) located on the hallway for the main and upper floor and smaller return in the basement.
    Thanks

  • tigerdunes
    10 years ago

    The AHRI number you provided is not found.

    Here are the matching AHRI numbers according to my research.

    5429554 Active Systems XC14 SERIES LENNOX INDUSTRIES, INC. XC14-042-230-** CX34-62C+TDR 1405 SLP98UH110XV60C* 42500 13.00 15.20 1 RCU-A-CB 338

    5139349 Active Systems XC17 SERIES LENNOX INDUSTRIES, INC. XC17-042-230* CX34-62C+TDR 1405 SLP98UH110XV60C* 41000 13.50 16.50 1 RCU-A-CB 301 Yes

    As said earlier, the XC17 system qualifies for fed tax credit, the XC14 system does not.

    The $2K up charge on the AC condenser from the XC14 to XC17 is absurd.

    Not a big deal on the larger evap coil. All manufacturers do this to get their efficiency numbers higher. The main thing to verify is the AHRI match and both these coils are a match. See above.

    Not sure what other info I can provide. If you are serious about the Lennox system, then tell dealer he must do something about the cost of the condenser upgrade.

    Let's see what Carrier/Bryant have to say.

    No doubt you are going to save a bundle getting off oil.

    Has dealer offered any recommendations to improve temp variance on the two problematic rooms? Press him on this. Now is the opportunity to get something done.

    Nothing wrong with existing filter cabinet. I assume you plan to reuse. Humidifier is your call. This is all about comfort and keeping inside humidity within a proper range during heating season. If not a problem now, why bother.

    Let me know if I can help further.

    Good Luck
    IMO

  • bingeo
    Original Author
    10 years ago

    Thanks Tigerdunes. Will be in touch with the Carrier/Bryant quote.

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