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  1. #14
    Join Date
    Feb 2006
    Location
    Float'N Vally, MS
    Posts
    1,834
    Quote Originally Posted by ccraven66 View Post
    Dan,
    3 ton is for upstairs 1000 sq feet, 4 ton for main level 2000 sq feet. house built in 2000. just finished bringing attic insulation up to R70 as well as air sealing all gaps and penetrations in attic.
    For a house built after 2000 with a good window schedule and insluation...
    That may be oversized for our swampy area.....

    You milage would vary....
    Life is too short, Behappy!
    TFMM

  2. #15
    Join Date
    Oct 2011
    Location
    Indianapolis IN
    Posts
    404
    If they are quoting you that Lennox XP21 and comparing it to an Infinity Greenspeed then that isn't apples to apples. Have them quote you a Lennox XP25 series and that will maybe get you closer. The Greenspeed is inverter technology and the XP21 is a 2 speed heat pump where the XP25 has inverter technology.

    Have you looked into that already?
    ______________________________

    I lift things up and put them down.

  3. #16
    Join Date
    Jun 2009
    Posts
    42
    Darrin
    I have not looked at the XP25. I will look.

  4. #17
    Join Date
    Feb 2010
    Location
    Metro Atlanta, GA
    Posts
    475
    Carrier also makes an Infinity heat pump without the Greenspeed technology if you wanted to compare more apples to apples price wise.

  5. #18
    Join Date
    Nov 2004
    Location
    SW FL
    Posts
    6,295
    Quote Originally Posted by ccraven66 View Post
    Dan,

    No Maytag HVAC dealers in GA. Room by room Manual J for main level calls for 3.5 ton. room by room manual j for second floor calls for 2 ton but contractor quoted 3 ton, don't know why.
    JOHNSTON CLIMATE CONTROL
    791 JOHNSTON OAK LN
    LILBURN, GA 30047 US

    WESTINGHOUSE = MAYTAG = BROAN = NORDYNE = TAPPAN = FRIGIDAIRE
    Designer Dan
    It's Not Rocket Science, But It is SCIENCE with "Some Art". ___ ___ K EEP I T S IMPLE & S INCERE

    Define the Building Envelope and Perform a Detailed Load Calc: It's ALL About Windows and Make-up Air Requirements. Know Your Equipment Capabilities

  6. #19
    Join Date
    Jun 2009
    Posts
    42
    Thank you Dan

  7. #20
    Join Date
    Mar 2006
    Location
    The South
    Posts
    2,197
    It would be helpful to know both your nat gas and electric rates. I would not make a decision on new system until this is known. The idea of dual fuel is to leverage electric versus nat gas. This was quite popular not so many years ago. In the South, electric is more regulated and rates have advanced. While nat gas is more marketplace priced and prices have declined. In many areas, it s difficult to make the case for DF. Post your rates and I will run a quick fuel comparison analysis for you.

    IMO

  8. #21
    Join Date
    Nov 2004
    Location
    SW FL
    Posts
    6,295
    Quote Originally Posted by ccraven66 View Post
    _____ MAIN Level ___ UPSTAIRS
    _____ 2,000 SQ.FT ---- 1,000 SQ.FT.
    Lennox XP21, 4 ton + ---- Lennox XP21, 3 ton
    Lennox CX34, 4 ton coil + -- Lennox CX34, 3 ton coil
    Lennox SL280, 90k BTU + -- Lennox SL280, 70k BTU
    160,000 BTU/HR could be nearly
    3.5 times Actual Needed

    SUMMER :
    Trying to achieve 70'F increases operating cost to nearly 2 X What's necessary for 76'F.
    Designer Dan
    It's Not Rocket Science, But It is SCIENCE with "Some Art". ___ ___ K EEP I T S IMPLE & S INCERE

    Define the Building Envelope and Perform a Detailed Load Calc: It's ALL About Windows and Make-up Air Requirements. Know Your Equipment Capabilities

  9. #22
    Join Date
    Nov 2004
    Location
    SW FL
    Posts
    6,295
    Quote Originally Posted by tigerdunes View Post
    It would be helpful to know both your nat gas and electric rates. I would not make a decision on new system until this is known.
    The idea of dual fuel is to leverage electric versus nat gas. This was quite popular not so many years ago. In the South, electric is more regulated and rates have advanced.
    While nat gas is more marketplace priced and prices have declined. In many areas, it s difficult to make the case for DF.
    Post your rates and I will run a quick fuel comparison analysis for you.

    IMO
    CHEAP
    http://www.energyshop.com/es/prices/...cfm?ldc_id=324

    x

    $0.11 to $0.13 for 1,000 kW per month Summer / Winter
    $0.10 to $0.14 for 1,500 kW per month
    http://www.psc.state.ga.us/calc/electric/gpcalc.asp

    The usefulness idea of heat pumps is to provide Comfort and
    economical heating at > 40'F
    where HSPF can be > 10.
    Designer Dan
    It's Not Rocket Science, But It is SCIENCE with "Some Art". ___ ___ K EEP I T S IMPLE & S INCERE

    Define the Building Envelope and Perform a Detailed Load Calc: It's ALL About Windows and Make-up Air Requirements. Know Your Equipment Capabilities

  10. #23
    Join Date
    Jul 2006
    Location
    Virginia
    Posts
    4,665
    i do like duel fuel in many situations although with a short mild winter and with natural gas i see no advantage
    We really need change now

  11. #24
    Join Date
    Mar 2006
    Location
    The South
    Posts
    2,197
    There is really little to no incentive going dual fuel with your current rates assuming a 95%+ high eff furnace.

    I agree about the suggestion of a properly sized HP system for upstairs. I would want a var speed air handler and a min 15 SEER model that qualifies for Fed Tax Credit.

    For downstairs a high eff two stage furnace with high eff AC. Now because of Hotlanta's moderate winter climate, you could consider an 80% eff furnace and then I would pair with a HP.

    IMO

  12. #25
    Join Date
    Jun 2009
    Posts
    42
    Quote Originally Posted by tigerdunes View Post
    It would be helpful to know both your nat gas and electric rates. I would not make a decision on new system until this is known. The idea of dual fuel is to leverage electric versus nat gas. This was quite popular not so many years ago. In the South, electric is more regulated and rates have advanced. While nat gas is more marketplace priced and prices have declined. In many areas, it s difficult to make the case for DF. Post your rates and I will run a quick fuel comparison analysis for you.

    IMO
    Tigerdunes,

    Below are my utility rates per KWh and Therm as well as the manual J for the main level and second floors of my home. Thanks for your input.

    Georgia Power Cost per KWh: June - Sep = 0.5 to 0.12 per KWh
    Oct - May = 0.4 to 0.6 per KWh

    Natural Gas Cost per Therm: 0.95 – 1.35 per Therm

    NOTE: When Georgia deregulated natural gas in 1998, my city decided to establish their own natural gas utility as did four or five other cities in Georgia. As a result, we do not have the option as other consumers in some Georgia cities to select our natural gas supplier with the best therm cost. We have to pay these high prices per therm no matter what.


    MAIN FLOOR
    Design Conditions: Athens, GA

    Indoor: Outdoor:
    Summer temperature: 74 Summer temperature: 97
    Winter temperature: 70 Winter temperature: 22
    Relative humidity: 50 Summer grains of moisture: 99
    Daily temperature range: Medium

    Building Component: Sensible Latent Total Total
    Gain Gain Heat Gain Heat Loss
    (BTUH) (BTUH) (BTUH) (BTUH)
    Whole House; 1,971 sq.ft. 35,340 7,227 42,567 47,027
    ( 3.5 tons )

    SECOND FLOOR
    Design Conditions: Athens, GA

    Indoor: Outdoor:
    Summer temperature: 74 Summer temperature: 97
    Winter temperature: 70 Winter temperature: 22
    Relative humidity: 50 Summer grains of moisture: 99
    Daily temperature range: Medium

    Building Component: Sensible Latent Total Total
    Gain Gain Heat Gain Heat Loss
    (BTUH) (BTUH) (BTUH) (BTUH)
    Whole House: 931.7 sq.ft. 15,625 3,708 19,333 24,453
    ( 1.5 tons )

  13. #26
    Join Date
    Nov 2004
    Location
    SW FL
    Posts
    6,295
    Quote Originally Posted by ccraven66 View Post
    Tigerdunes,

    Below are my utility rates per KWh and Therm as well as the manual J for the main level and second floors of my home. Thanks for your input.

    Georgia Power Cost per KWh: June - Sep = 0.5 to 0.12 per KWh
    Oct - May = 0.4 to 0.6 per KWh

    Natural Gas Cost per Therm: 0.95 – 1.35 per Therm

    NOTE: When Georgia deregulated natural gas in 1998, my city decided to establish their own natural gas utility as did four or five other cities in Georgia. As a result, we do not have the option as other consumers in some Georgia cities to select our natural gas supplier with the best therm cost. We have to pay these high prices per therm no matter what.

    Building Component: Sensible Latent Total Total
    Gain Gain Heat Gain Heat Loss
    (BTUH) (BTUH) (BTUH) (BTUH)
    Whole House; 1,971 sq.ft. 35,340 7,227 42,567 47,027
    ( 3.5 tons )

    SECOND FLOOR
    Gain Gain Heat Gain Heat Loss
    (BTUH) (BTUH) (BTUH) (BTUH)
    Whole House: 931.7 sq.ft. 15,625 3,708 19,333 24,453
    ( 1.5 tons )
    I guess you meant _Georgia Power Cost per KWh:
    June - Sep = 0.05 to 0.12
    Oct - May = 0.04 to 0.06 per KWh
    Designer Dan
    It's Not Rocket Science, But It is SCIENCE with "Some Art". ___ ___ K EEP I T S IMPLE & S INCERE

    Define the Building Envelope and Perform a Detailed Load Calc: It's ALL About Windows and Make-up Air Requirements. Know Your Equipment Capabilities

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