Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

adjusting airflow on Trane Gas Furnace

Options
zepfan
zepfan Member Posts: 438
in A-C, Heat Pumps & Refrigeration

I am trying to find out how to adjust the airflow on a Trane communicating furnace

Model# TUD2C100ACV52BA

The furnace is being controlled by a Trane thermostat is a model# TZON1050AC52ZB

Both the thermostat, and the furnace were installed in 2018, by others. The issue is that the air conditioner that is part of the system is four tons, 2 stage. The issue is that the interface on the furnace is indicating that the system is in second stage cooling, with an airflow of 1100cfm. This is resulting in good humidity removal, but the ductwork in a conditioned basement is sweating all over the place. The supply temperature is in the low 40's and well below dewpoint. I think if I can adjust the airflow closer to 1600 cfm the supply temperature will go up, and the issue will go away. I have found the instructions on the thermostat, but I can not find anything on the furnace. There are no dipswitches just the interface on the furnace.The other thing is that there are no thermostat wires connected to the conventional terminal block in the furnace, just one wire on the d terminal, i assume for dehumid. I assume the operation is controlled by some type of communication protocol like carrier infinity, but I did not see even a ABCD terminal block. Any assistance would be much appreciated. I am not trying to re design the whole system just adjust the airflow up to stop the duct from sweating. Thanks to all.

Comments

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 18,262

    I couldn't find the Trane manual although I searched for it. The answer is in the manual I am sure.

    Your down to 275 cfm/ton so that is too low. Is the unit oversized? 100,000 btu and 4 tons is pretty big.

  • pecmsg
    pecmsg Member Posts: 6,300
    edited July 27

    How are you measuring the CFM‘s? If on the thermostat, it’s very inaccurate! That is the calculated CFM not actual.

    You need someone there taking static pressure readings to determine the actual CFM’s.

  • HVACNUT
    HVACNUT Member Posts: 6,869

    Insulate the ductwork. Up in the Bay spaces won't sweat.

  • zepfan
    zepfan Member Posts: 438

    thanks for the responses. The cfm is what is being read on the furnace interface Yes I am fully aware that with the total ESP and the airflow table the correct cfm can be determined, however I can not find a manual that even lists that

  • ratio
    ratio Member Posts: 4,068

    Check the thermostat for a dehum setting, it may be commanding the fan to low speed to dehumidify.

    Do you have an installation manual for the thermostat? With no settings available in the furnace the next place I'd look for configuration options is in a communicating thermostat.

    Maybe try lifting the wire off of the D terminal, IIRC that influences fan speed.

  • pecmsg
    pecmsg Member Posts: 6,300
    https://forum.heatinghelp.com/discussion/comment/1861075#Comment_1861075

    That reading is Calculated not an actual CFM #. Real test equipment is needed to get the actual Static Pressure

Categories