Results 1 to 13 of 13
  1. #1
    Join Date
    May 2000
    Location
    Urbandale IA. USA
    Posts
    4,925
    2 stage Variable Speed

    Scenario #1
    Single stage Tstat
    W1 jumpered to W2
    Staging set to (7.5 min)

    Scenario #2
    Single stage Tstat
    W1 jumpered to W2
    Staging set to (15 min)

    Scenario #3
    Two stage Tstat
    Proper Tstat to furn wiring


    Which is the most efficient for cold climates like Kansas Missouri and north?
    Please give simple explanation as to WHY.

    Those who dance, appear insane to those who do not hear the music.
    Those who believe, appear ignorant to those who do not know God.

  2. #2
    Join Date
    Mar 2005
    Location
    burlington county n.j.
    Posts
    9,741
    2 stage stat better for any area. unit will only go to 2nd stage when needed not by time. unit will come back down to low fire instead of satisfying and shutting off from high fire.longer run cycle on low fire= more even temperature

  3. #3
    2 stage equipment deserves a 2 stage stat!

    Why pay all that extra for a 2 stage unit, then not get the full benefits by installing a single stage stat?

    That just don't make very much sense.

  4. #4
    Join Date
    Apr 2004
    Posts
    7,680
    Efficiency cant be the issue. Its a matter of comfort. The best case, as mentioned should be a two stage stat. This will ensure the unit runs in low stage more often. However, in order for it to go to second stage the thermostat must have the additional call meaning you are further from set-point. (as much as 1.5-2 degrees).

  5. #5
    Join Date
    Dec 2002
    Location
    Rochester, MN
    Posts
    5,304
    Two stage t-stat for a two stage furnace.. No questions.. Gives you the best comfort.

  6. #6
    Join Date
    May 2000
    Location
    Urbandale IA. USA
    Posts
    4,925
    Originally posted by docholiday
    Efficiency cant be the issue. Its a matter of comfort. The best case, as mentioned should be a two stage stat. This will ensure the unit runs in low stage more often. However, in order for it to go to second stage the thermostat must have the additional call meaning you are further from set-point. (as much as 1.5-2 degrees).
    Thanks Doc,
    This is what I am questioning.
    If a 2 stage Tstat is 1.5-2 degrees lower BEFORE second stage kicks in, then on the coldest days and nights you will always be 2-3 degrees cooler than the warmer days/nights when second stage is not needed.

    I installed a new 2 stage and set it for a 10 min delay before second stage kicks in. It is wonderful. It does NOT go to second stage yet, but it has not gone below freezing yet.

    I have been selling many VS-2stage units since I installed my own.
    Lesson for salesmen---- You will sell more of what you OWN than what you don't own......

    Chris
    Those who dance, appear insane to those who do not hear the music.
    Those who believe, appear ignorant to those who do not know God.

  7. #7
    Join Date
    Apr 2004
    Posts
    7,680
    Well, I Dont believe once it goes into high fire you will continue to lose temps. Many of the digital stats have adjustable differentials. The key is to set it where you are comfortable. It will also recover and generally run until both stages satisfy. The option is clearly yours and the technician should offer both options.

    The two stage stat comes in handy because in mild temps, it will hold first stage indefinately. If the load on the house is at or below the first stage setting, it will remain very comoftable. Under most conditions, it will be that much more comfortable to operate on a two stage stat.

    If you want exact control the only real option is the mod.


  8. #8
    Join Date
    Dec 2002
    Location
    Rochester, MN
    Posts
    5,304
    My vision Pro kicks in 2nd stage in 1 degree of set point.. I didn't feel cold at all last winter when it was -23 out.

    A neighbor behind me has the same floor plan as ours, and thier basement was updated, but our still was much warmer with the two stage vs the single stage that they had..

    The did change the t-stat to two stage after feeling how much better ours was. They felt warmer too in the basement.

  9. #9
    Join Date
    Nov 2004
    Location
    SW FL
    Posts
    6,274

    Thumbs up Feeling

    Originally posted by mayguy
    I didn't feel cold at all last winter when it was -23 out.
    YOU MUST have Great jacket, hat and gloves to withstand that temperature and not feel cold.
    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. #10
    Join Date
    Dec 2002
    Location
    Rochester, MN
    Posts
    5,304

    Re: Feeling

    Originally posted by dan sw fl
    Originally posted by mayguy
    I didn't feel cold at all last winter when it was -23 out.
    YOU MUST have Great jacket, hat and gloves to withstand that temperature and not feel cold.
    Just a regular winter jacket, and gloves.. As long the wind isn't blowing, it's fine.

    When I had EMT training, they said not to over dress.. if you overdress, you may sweat, and moisiter will make feel colder.

  11. #11
    Join Date
    Apr 2005
    Location
    Tampa, Florida
    Posts
    1,634
    Originally posted by cehs
    This is what I am questioning.
    If a 2 stage Tstat is 1.5-2 degrees lower BEFORE second stage kicks in, then on the coldest days and nights you will always be 2-3 degrees cooler than the warmer days/nights when second stage is not needed.

    I installed a new 2 stage and set it for a 10 min delay before second stage kicks in. It is wonderful. It does NOT go to second stage yet, but it has not gone below freezing yet.
    The better digital stats use mathematical formulas rather than arbitrary differentials to determine when to engage the first & second stages. The big difference between these type of stats and relying upon the timer-based differentials/staging is that the 2-stage stats usually will go back from 2nd stage to 1st stage only as it approaches the setpoint. So, it'l do off-1-2-1-2-1-off, etc. Whereas the timer will do off-1-2-off-1-2-off. This will give you longer runtimes, which will prolong equipment life (fewer start-stops) and should be more efficient because the heat exchanger/coils will be kept warm (going into 1st stage rather than full off) rather than letting them go cold, etc.

    mayguy: anything cooler than 65F is COLD to Floridans. -23 is unimaginable.

  12. #12
    Join Date
    Nov 2004
    Location
    SW FL
    Posts
    6,274

    Talking Define Winter

    Originally posted by tpa-fl


    mayguy: anything cooler than 65F is COLD to Floridans.
    -23 is unimaginable.
    FLORIDAH Math
    93'
    -23'
    70'F = Winter

    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

  13. #13
    Join Date
    Dec 2002
    Location
    Rochester, MN
    Posts
    5,304

    Re: Define Winter

    Originally posted by dan sw fl
    Originally posted by tpa-fl


    mayguy: anything cooler than 65F is COLD to Floridans.
    -23 is unimaginable.
    FLORIDAH Math
    93'
    -23'
    70'F = Winter

    When i was a kid, we went to Fla for the first time in '84.. It was Dec.. one night, it got down to 40's/50's

    When we left the hotel, we were in our shorts, and tank top.. Going by the phone guy who was working on some lines, he was all wrapped up in heavy coat, ear flaps hat, and heavy glove, and a fire pit going next to him! We had to laugh.

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