Results 1 to 13 of 13
  1. #1
    Join Date
    Apr 2012
    Posts
    9

    Is Dual Stage AC and Communicating Infinity worth a little extra?

    I'm replacing my gas furnace and air conditioning unit. My furnace is located in the attic of a 3 floor town-house.

    The 2 proposals that I'm considering are as follows:

    Carrier Infinity System:

    Carrier 58CVA070-12 2-Stage, Variable Speed Infinity Series gas Furnace
    Carrier 24ANB724 2-Stage Infinity Series Air Conditioner
    Carrier CNPVP3617A 2.5ton Indoor Evaporator Coil
    Carrier Digital Programmable Thermostat
    Aprilaire 2210 Media Filter (8-12 month longevity))

    Trane System:

    XV80 TUD2B060A9V3VA (If this is in the attic should it be the downflow?)
    XL 15i
    Trane 4TXCB025
    Honeywell Programmable Thermostat
    They will also modify the return supply duct and install an adjustable manual damper
    17.5SEER

    My main question/concern is if the price difference should I really consider the infinity system due to the communicating capability and dual stage AC? I currently have zero issues with noise even though the current unit was installed about 14 years ago. I just have a huge difference in temperature from floor to floor and my assumption is that's due to the unit being located in the attic.

    Let me know what you think and thank you very much.

  2. #2
    Join Date
    Jun 2003
    Location
    Madison, WI/Cape Coral, FL
    Posts
    6,373
    Quote Originally Posted by Prochu View Post
    I'm replacing my gas furnace and air conditioning unit. My furnace is located in the attic of a 3 floor town-house.

    The 2 proposals that I'm considering are as follows:

    Carrier Infinity System:

    Carrier 58CVA070-12 2-Stage, Variable Speed Infinity Series gas Furnace
    Carrier 24ANB724 2-Stage Infinity Series Air Conditioner
    Carrier CNPVP3617A 2.5ton Indoor Evaporator Coil
    Carrier Digital Programmable Thermostat
    Aprilaire 2210 Media Filter (8-12 month longevity))

    Trane System:

    XV80 TUD2B060A9V3VA (If this is in the attic should it be the downflow?)
    XL 15i
    Trane 4TXCB025
    Honeywell Programmable Thermostat
    They will also modify the return supply duct and install an adjustable manual damper
    17.5SEER

    My main question/concern is if the price difference should I really consider the infinity system due to the communicating capability and dual stage AC? I currently have zero issues with noise even though the current unit was installed about 14 years ago. I just have a huge difference in temperature from floor to floor and my assumption is that's due to the unit being located in the attic.

    Let me know what you think and thank you very much.
    The variable speed furnace fan is nice for the low speed recirc which mixes the home for even temps. In northern green grass climates, the value of the two speed a/c is pitched as better humidity control. While it helps a little, during low/no cooling loads, no dehumidification occurs. I suggest the furnace you selected, regular a/c, and a small whole house dehumidifier for ideal temp/%RH throughout the home in all weather loads.
    Regards TB
    Bear Rules: Keep our home <50% RH summer, controls mites/mold and very comfortable.
    Provide 60-100 cfm of fresh air when occupied to purge indoor pollutants and keep window dry during cold weather. T-stat setup/setback +8 hrs. saves energy
    Use +Merv 10 air filter. -Don't forget the "Golden Rule"

  3. #3
    Join Date
    Apr 2012
    Posts
    9
    Thank you for your advice.

    I should have added that I'm located in the Northern VA area. During the winter my home has been uncomfortably dry so I started using a large humidifier on the middle floor, I may purchase one for the bedroom depending on how dry it is this winter.

    I haven't noticed any humidity issues during the summer so far.

    Thanks again!

  4. #4
    Join Date
    Jul 2006
    Location
    Virginia
    Posts
    4,633
    If possible I would have a zone system added and a whole house humidifier installed . My ote is for the infinity with a infinity control

  5. #5
    Join Date
    Apr 2012
    Posts
    9
    Thank you catmanacman, Dual Zoning is out of my price range at this time.

  6. #6
    Join Date
    Aug 2007
    Location
    Northern VA 38 degrees N by 76 degrees W
    Posts
    5,060
    Go with the Trane system and spend the difference on evaluating air leakage into the home and air flow issues to the space.

    Communicating controls will not help you systems performance.

  7. #7
    Join Date
    Aug 2009
    Location
    Jurupa Valley, CA
    Posts
    1,778
    You will never have even comfort levels single-zoning a 3-story townhome. There's just too much difference from season to season. Ideally, it might be better to split the system between lower and upper floors (as opposed to a single unit with zoning dampers).

    Personally, I'd rather spend the extra money on zoning or splitting a lower efficiency unit(s), than on a single-zone higher efficiency unit. For me, the primary goal of HVAC is comfort.

  8. #8
    Join Date
    Apr 2012
    Posts
    9
    Thank you for your suggestion CraziFuzzy

    I'm really only super concerned with the top 2 floors to be honest, as long as I can cut the difference by a bit I'll be happy. In the prior years it has been like an oven on the upper floor in the winter and almost comfortable on the middle floor, the ground floor is always cooler.

    I'm just trying to figure out if the extra $$ for the Infinity system is worth it and will it make any difference with the dual compressors as far as comfort?

  9. #9
    Join Date
    Aug 2009
    Location
    Jurupa Valley, CA
    Posts
    1,778
    your problems are with air flow. The problems are in the ducts, not the unit. You could spend thousands of dollars, and it still won't fix the underlying problem.

  10. #10
    Join Date
    Apr 2012
    Posts
    9
    Well, without tearing up the floor or ceiling do you think an adjustable damper will help? Do you have any other suggestions?

  11. #11
    Join Date
    Aug 2009
    Location
    Jurupa Valley, CA
    Posts
    1,778
    Adjusting the air flow with dampers likely would help - however, only for a particular situation. Once the weather changes, it will have to be adjusted again, and again, and again, to maintain comfort. This, really, is what the simpler zoning systems do, they make these adjustments automatically for you.

  12. #12
    Join Date
    Jan 2009
    Location
    Keokuk, IA
    Posts
    5,520
    IF you can't get the air up there, you can't get BTU's where they need to go. 2 option if you're not willing ot open up walls and make space. 1) high velocity (uses higher air pressure ot get more air volume through the same ductwork. 2) Mini splits or VRF units (multizone minisplits). IF you can't get the air up there, then get ther run a pipe wiht refrigerant up there.

    I'll put it this way. IF you need to remove lets say 30,000 BTU's of heat form your upstairs and you want to maintain 75F. If the air temperature in the ductwork is 50F, then you need to get 1100CMF trough that ductwork to maintain 75F. End of story. Depnding on you climate and humidity levels you would need 3 tosn to deliver 1100CFM of 50F air. See how that works?

    IF you try to keep supply velocities under 1000fpm (800-900 is better), then you need 160sq inches of duct area.

  13. #13
    Join Date
    Apr 2012
    Posts
    9
    Thank you all for your help, I really appreciate it.

    Have a good one.

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