Problems with tranquility 27

Discussion in 'General Discussions' started by firefly country, Jan 24, 2009.

  1. The main problem we are having with the unit is the auxilary heat is on 90% of the time. Our electric bill is through the roof.
    History: We bought a Tranquility 27, 5 ton in May 2006. In the first year the unit in the heating cycle would turn the auxillary heat on at around -5 c.( We had to turn the auxiliary on as ice appeared on the pipes leading into the furnace and the unit was not able to heat the house). We live in southern Ont. and in an older home 2200 sq/ft. unheated basement .( new outside doors, some new windows, new insulation installed in some walls, no drafts)
    Present: Since November 2008 our unit has been running all the time either on heat or auxillary heat. It never shuts off. It does not matter if it is 2 degrees celcius outside or -28 c. The unit is always running in both modes. Service tech said it was the filter. We changed the filter and still had the same problem. Tech came back again on Jan 7th, all pressures and temperatures were fine he said. He told us to turn off the auxillary breaker and see what would happen. Within 2 hours the temp. started dropping the unit was unable to keep our house at 20c. After it dropped by 5 degrees we had to turn the auxillary heat back on. Service tech said he would come back on the 19th. When he did not show up, called the company and he said he would be out in a few days but thought it was our unheated basement causing the problems. On Jan. 22 new service tech with a different company came out at our request, he agreed there was a problem and was very helpful but still could not find the problem. There were no code errors showing in the furnace, but he felt that the temperatures leaving the furnace should be 10 degrees higher. (He measured 90 degrees F at the furnace( heat pump ) Temperatures taken at floor registers vary, 69-73 F when the geothermal is on and 81-83 F when the auxillary is on. (Although once I did see a reading of 100F on auxillary) This furnace is costing me a lot to heat my house Please can anyone give me some ideas on how to fix this problem. Thanks.
     
  2. geo fan

    geo fan Member Forum Leader

    since the problem developed the answer is a leak , refrigerent or water
    Water should be eisily noticed , so its likely refirgerent
    have the second tech go over everthing with a sniffer if he hasnt allready
    if its a package unit it should be pretty simple
    because your system is r410a all refrigerent will have to be reclaimed you can NOT add refrigerent
     
  3. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    That or I wonder if a significant leak of unheated air is entering the return

    Measure air temp as close as possible to unit, such as at air filter
     
  4. Thanks for your help. The service tech measured the return air at the furnace at 68 F. The cold air return vent on the main floor was 70F.
     
  5. waterpirate

    waterpirate Well-Known Member Industry Professional Forum Leader

    Delta t air coil

    Welcome firefly,

    If the return air at the unit is 68, what is the output at the unit with aux heat off?

    Also a Delta t at the exchange coil, what is the incoming fluid temprature and the outgoing fluid temprature?

    Also a delta p at the exchange coil, what is the incoming pressure of the fluid, and the outgoing pressure of the fluid?

    These three things will make quick work of the diagnosis of your problem when cross refferanced with the performance data of your unit. Ask your tech for them. If he can not provide them get another tech.
     
  6. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    Geofan

    410A can be added.

    Puts on foil hat.

    Has epa universal refrigerant card.

    Could buy R-11 if there was any left.
     
  7. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    BTW

    Geo is correct, something is leaking. Air flow, loop, or refrigerant.

    Could be a bad ECM motor drive.
     
  8. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    OK, possibility of return air leak is eliminated - good

    I'm mystified by this statement in your original post:

    "Currently at 90 degrees F. Temperatures at register vary between 69 F when the geothermal is on and 83 F when the auxillary is on."

    Clarify that and get WaterPirate's ???s answered.
     
  9. Thanks for all your replies and assistance. I have edited my original post, hopefully my information is clearer. I will talk to my tech on Monday to see if I can get those values and pass them on.
     
  10. geo fan

    geo fan Member Forum Leader

    your scaring me

    I dont know who told you that there is no concern with fractionalization but the where most likely not working on a 20k plus system puchased for eff. If there was no concern ( and I do releize the small temp glide) why for propper charging do you HAVE to charge with liquid ?
    Near azeotrope and azeotorpe are very different
     
  11. geo fan

    geo fan Member Forum Leader

    While r410a has a small temp glide , there is a risk of fictionalization . This is why the pink can always has to be upside down . If there is a leak on a r-410a system and the leak is on the vapor line you have no idea if the mix is still 50/50 . a mix that is not right will not preform right and be very difficult to diagnose in the future ( from experience ) again you are taking a gamble with someone else's property when they may be more then willing to pay to have it done right
     
  12. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    Geofan

    I concur, with a too small repy
     
  13. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    I'm still a bit confused

    "...he felt that the temperatures leaving the furnace should be 10 degrees higher(currently at 90 degrees F) Temperatures taken at register vary, 69-73 F when the geothermal is on and 81-83 F when the auxillary is on..."

    OK - your thermostat setpoint is 20C which is 68 F. If the system gets 68 deg F return air and supplies 90 deg F, that's OK for compressor-only stages. Aux should add 10-20 deg F to that, depending on CFM and KW of heat strips.

    What register (supply or return) is at 69-73 F on geo and 81-83 with Aux?

    My confusion is coming from trying to understand the 90 degrees vs 69-73 / 81-83.
     
  14. Palace GeoThermal

    Palace GeoThermal Well-Known Member Industry Professional Forum Leader

    I might be wrong, but I think the 90° is right off the top of the heat pump while the 69-73 is at the registers.
     
  15. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    Heckuva duct loss if so...
     
  16. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    410a

    may not be what is in his/her machine.
     
  17. Thanks to everyone that replied. I am still in the process of getting the exact pressure readings and temperatures that Water pirate and engineer asked for. (spouse forgot to ask for delta t and delta p readings).
    The tech did say that they were all in the normal range but some were on the low side of the normal range. I remember he said the temp of the loop was 30 or 32. Is that normal? I thought it should be higher.

    The service tech, after consulting with a next energy sales rep and relaying the pressures and temperatures to the rep, feels that we have an air flow problem and should be enlarging our cold air duct work and putting in a new electostatic air filter. He felt that the aprilaire filter was not allowing enough air through and our duct work was not big enough. I agree with this and feel that this would make our system more efficient. However, that still does not account for the fact that this is the third year we are using our furnace and the auxillary heat only started coming on continously this past November. The last few years we did not have this problem. Although I always felt it came on too much, the furnace would cycle on and off through out the day.

    We have been renovating this fall, drywalling and lots of dust. We closed off the two rooms we were working on, vents were closed and blocked off. Two dropped ceilings were removed and we added a new heating vent to a small room upstairs (9x 6). New insulation was added also. Would any of these changes be affecting our furnace and how it is running?
    Can you buy the correct tools to measure all the pressure and temps, so we don't have to rely on service people?
     
  18. Stats for furnace

    Sorry to take so long but here are the stats for my furnace.


    Loop temps- 29.8 and 34.4 degrees
    Return air temp 68.3 degrees
    Supply Air temp without electric duct heater 85.5 degrees
    Delta T is 16.7
    Supply temp with Electric 101 degrees
    incoming/ outgoing Delta P was 5 psi

    Any thoughts would be appreciated. Thanks
     
  19. kimko

    kimko New Member

    how many hours of run time elapsed before you took those readings, try taking them first thing in the morn after its ran all night
     
  20. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    Air side delta-T of 16.7 degrees on geo alone does NOT suggest low airflow. Typical Delta-T is 20-25.

    An overly restrictive air filter or inadequate ductwork would reduce airflow. That would drive delta-T to the upper part of the 20-25 range or a bit higher.

    Do you know KW rating of aux heat strips? With that plus temperatures you have provided we could roughly calculate air flow
     

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