Page 1 of 3 123 LastLast
Results 1 to 13 of 30
  1. #1
    Join Date
    Jan 2004
    Posts
    60

    2 stage variable speed operation

    Can some one explain to me proper order of operation of the 2 stage var speed system to use all the benefits of it?

    For example: Thermostat calls 1st stage, 2nd, then off, again 1st, 2nd off
    That seems how mine is setup

  2. #2
    Join Date
    Aug 2002
    Location
    Office and warehouse in both Crystal River & New Port Richey ,FL
    Posts
    18,836
    There are different setups ,what brand and models,including the thermostat??

  3. #3
    Join Date
    Jul 2004
    Location
    Massachusetts
    Posts
    6,841
    Sure. Non-program operation: T-stat calls sytem on, initally 1st stage operation. System runs on first stage until A. the t-stat is satisfied or B. the temperature continues to move away from t-stat set point, at which time 2nd stage comes on, runs until the t-stat is moved back toward set point, operation returns to first stage and operates as in A/B above.

    Programmable operation: When the programmed event is reached that activates the system, it comes on in first stage for a period of time, perhaps 10-minutes and if the t-stat isn't satisfied at that time, the system bumps to 2nd stage until the t-stat is satisfied. Then the system cycles off and normal 1st, 2nd stage operations take over.

    Variables of this operation can be because of thermostat, numbers of wires or set-up issues. e.g. It's not uncommon to find 2-stage gas furnaces with the dip switches set to operate the system as it is always recovering from a new programmed event. That is, 1st stage for a set period of time, then if the stat is still calling, bump to 2nd stage for the duration. Usually this is beause there weren't enough wires to the t-stat to accommodate 2-stage operation. FYI Carrier/Bryant products now have the capacity to do full 1/2 stage cycling without timers using just 4, #18 t-stat wires.
    If YOU want change, YOU have to first change.

    If you are waiting for the 'other guy' to change first, just remember, you're the 'other guy's' other guy. To continue to expect real change when you keep acting the same way as always, is folly. Won't happen. Real change will only happen when a majority of the people change the way they vote!

  4. #4
    Join Date
    Jan 2004
    Posts
    60

    skippedover

    so who or what exactly is doing up and down staging, thermostat?

  5. #5
    Join Date
    Jul 2004
    Location
    Massachusetts
    Posts
    6,841
    That's correct. You need the proper thermostat to do the job. t-stats come as heating only, 1-C/1-H, 1-C/2-H, 2-C/3-H. Some more exotic variations can be had and you have to be careful you get the stat that's not only appropriate by stages but also by gas/electric or heat pump. Some do all and all do some. (Elton John?)
    If YOU want change, YOU have to first change.

    If you are waiting for the 'other guy' to change first, just remember, you're the 'other guy's' other guy. To continue to expect real change when you keep acting the same way as always, is folly. Won't happen. Real change will only happen when a majority of the people change the way they vote!

  6. #6
    Join Date
    Jan 2004
    Posts
    60

    skippedover

    So there is a thermostat which will stage down at some point during the same cooling cycle for?

    Is that how all that advanced technology being utilized or am I missing a point of 2stage var speed high seer etc, etc...

  7. #7
    Join Date
    Jul 2004
    Location
    Massachusetts
    Posts
    6,841
    Yes there are many thermostats that will do that for you. There are various after market stats and also manufacturer stats. The Honeywell VisionPro line of t-stats are an example of after market stats that can do all you want. Just be sure to get the right one as I described earlier. Different models do different things.
    If YOU want change, YOU have to first change.

    If you are waiting for the 'other guy' to change first, just remember, you're the 'other guy's' other guy. To continue to expect real change when you keep acting the same way as always, is folly. Won't happen. Real change will only happen when a majority of the people change the way they vote!

  8. #8
    Join Date
    Aug 2002
    Location
    Office and warehouse in both Crystal River & New Port Richey ,FL
    Posts
    18,836
    Some controls acually track the progress to set point,holding it in low stage as long as it is making progress to the set point.

    They also have dehumidification mode,to lower the air flow,while cooling to reach the summer humidity set point.

    Some can run in low to dehumidify,whn there's no call to cool.

    What brand/model do you have ?

  9. #9
    Join Date
    Jan 2004
    Posts
    60
    Thanks guys

    Dash - I have recently installed York 2 stage var speed dual fuel HP - 2 stage natural gas furnace, do not know what a model number is, plus it's zoned and controlled by 3 different, single stage thermostats and EWC control panel

    CFM board set for high humidity profile plus I can get 15% more with dehumidistat. Can Vision pro used instead of it or it dehumidifies by over cooling?

  10. #10
    Join Date
    Aug 2002
    Location
    Office and warehouse in both Crystal River & New Port Richey ,FL
    Posts
    18,836
    With some zoning systems you lose some dehumidification features.I not familar with that brand so best for someone who is to answer.

    Might want to start a new tread to ask that question.

  11. #11
    Join Date
    Jul 2004
    Location
    Massachusetts
    Posts
    6,841
    Quote Originally Posted by alex123 View Post
    Thanks guys

    Dash - I have recently installed York 2 stage var speed dual fuel HP - 2 stage natural gas furnace, do not know what a model number is, plus it's zoned and controlled by 3 different, single stage thermostats and EWC control panel

    CFM board set for high humidity profile plus I can get 15% more with dehumidistat. Can Vision pro used instead of it or it dehumidifies by over cooling?
    Ah, when you get into zone controls, everything changes. Most zone controls, including EWC, Honeywell, Arzel and other 'after market' brands don't allow full control over the system staging. They usually have a built in timer at the zone control panel that stages the equipment. For example, it allows the system to run for 10-minutes on 1st stage, then moves to 2nd stage. On the other hand, some of the manufacturer's zone control systems do allow total staging control as well as many other enhancements. Of course, those all cost more as well. It's not at all uncommon to see new equipment matched up with after market zone controls and they work just fine but personally, I think a little something is surrendered when you can't get the full benefit of 2-stage equipment.
    If YOU want change, YOU have to first change.

    If you are waiting for the 'other guy' to change first, just remember, you're the 'other guy's' other guy. To continue to expect real change when you keep acting the same way as always, is folly. Won't happen. Real change will only happen when a majority of the people change the way they vote!

  12. #12
    Join Date
    Feb 2004
    Location
    Wadsworth, OH
    Posts
    316
    Quote Originally Posted by alex123 View Post
    Thanks guys

    Dash - I have recently installed York 2 stage var speed dual fuel HP - 2 stage natural gas furnace, do not know what a model number is, plus it's zoned and controlled by 3 different, single stage thermostats and EWC control panel

    CFM board set for high humidity profile plus I can get 15% more with dehumidistat. Can Vision pro used instead of it or it dehumidifies by over cooling?
    The Arzel Heat PumPro panel was designed for zoning multi-stage heat pump applications.
    It controls staging based on a required minimum leaving air temperature. That min LAT resets as the outdoor temperature changes. The Min LAT is increased one half degree for every one degree of ODT decrease. So as the heat loss of the house increases with a drop in ODT and the heat pump output capacity decreases, the HPPro proactively stages up the equipment to meet the current min LAT. As zones satisfy and the LAT increases with a decrease in air flow across the coil, the HPPro will stage back down to meet the current needs of the home.
    The downside of staging from the thermostat is that the room temperature has to drop 1.5 to 2 deg before the 2nd stage is initiated.
    "When you perceive zoning not as a bandage but as an enhancement, you truly understand the dynamics and limitations of forced air heating and cooling"

  13. #13
    Join Date
    Jun 2003
    Location
    Madison, WI/Cape Coral, FL
    Posts
    6,587
    Quote Originally Posted by dash View Post

    Some can run in low to dehumidify,whn there's no call to cool.
    This dehumidification feature sounds like humidity control without comfort or energy penalty.
    If we have a 2,500 sqft. home at 75^, 60% with out any cooling load 70^F, 90%RH raining/night: How many minutes will an a/c operate on low before the temp is lowered 3^F? How many btus of sensible cooling/low speed cooling with 3 ton required to remove 50-75 pints of moisture per day while maintaining 50%RH? How much colder will the home be when there is no cooling load? What is the pints/KW using a/c? Dehu TB

Page 1 of 3 123 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event