Carrier Infinity Air Conditioner
I have installed an Carrier Infinity Air Conditioner (2 ton) a couple of years ago. Since the installation, I noticed a lot of sweating on the plenum on the side coressponding to the ends of the coil inside the plenum. The sweating was so much that large beats of condensation would appear shortly after the air conditioner is turned on and would eventually drip down the side of the plenum.
I contacted the contractor who did not do anything and eventually contacted Carrier. They did a number of tests and moved the coil inside the plenum towards the centre (it was installed to one side of tbefore) That did not cure the proble. Condensation still appears. This summer, they are coming back but before I have to deal with them again, I would like to learn more about the issue and perhaps others experience in this area.
Last edited by jimf8888; 02-02-2010 at 11:05 PM.
One of two problems I have seen causes this:
1.You have a air infiltration leaking into the area where the system is mounted.. this outdoor air may be very humid and the cold metal is sweating like a cold beer can out in the summer heat..
2.You have too low of airflow across your coil.. i.e. your system is configured to the wrong airflow..
or the last possibilty is the ductwork needs to be sealed and insulated..
I think it might be an air flow issue as the coil is installed in exactly the same location as my old aire conditioner coil and no sweating appeared in the old unit. This new one is a figh efficiency AC. The motor was also changed when the AC was installed.
If it was an air flow issue, how can one address it?
So you have a carrier 2-stage airconditioner,, What furnace do you have? Was the furnace replaced also.. If you could provide the model #'s for the furnace and a/c, might help with a solution.. Also what model thermostat you have..
please take a pic of your problem areas- i have an ideas on what is wrong.
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Why did they change the motor on your 58CVA90 when they installed the new A/C?
Originally Posted by jimf8888
If you have the Infinity control. Then teh control will tell you your static pressure. And you'll know if you have an air flow problem.
Thank you all for your input. Let me step back and explain the whole picture more clearly.
I installed an Infinity 2 stage mid efficiency furnace about 4 years ago (model number is 58CVA90) At that time, I believe they installed a new DC motor / fan. At the same time an Infinity programmable control (model SYSTXCCUID01) was installed. A year later, I installed a new Infinity high efficiency AC (model: 24ANA724A300, 17 seer, 2 ton )
The furnance is situated in a very small enclosed space (see picture attached). The space has a door but most of the time, the door is left open.
The Infinity control does show the pressure of the air flow. but I am not sure what is the correct pressure for suitable air flow.
Last edited by jimf8888; 02-03-2010 at 06:20 PM.
Reason: rotate picture
Post the CFM's and the pressures at those CFMs.
I don't have the pressure & air flow numbers for the air conditioner but with the furnance on, the numbers are as follows:
-High heat air flow: 1190 CFM
Blower RPM: 1041
Static pressure: 0.66
low heat: air flow:983 CFM
blower rpm: 849
static pressure: 0.43
does these make sense?
Is the evaporator coil an a-coil or n-coil?
Why did they not install a cased evaporator coil on the furnace? You had plenty of room and it would be a perfect fit..
I believe you may have some air bypassing problems on that coil installation which may be causing some cold spots on the coil which will translate to water developing in same areas on the plenum.. Or do you have a fresh air pipe installed in that room? If so, you may need to have the supply plenum insulated in the room as when your infinity air conditioner is running in dehumidification mode, it runs a very cold coil temp and may be getting the plenum cold enough to condensate.. If this is the problem there are settings in the infinity control to add more airflow to stop or limit the sweat problem..
Advanced Response (AR) is definitly heading you in the right direction. I would suspect an insulation problem first off. Hey AR I wonder if when they made the change they reprogrammed the UI or if it is still trying to communicate with the older model.
I am not sure if the coil is an a coil or n-coil. see the picture and may be you can tell.
You also mentioned that one can use the Infinity control to increase the air flow. can you tpls tell me how. I seem to recall reading about "confort" vs "efficiency" setting somewhere in the manual.
I agree with AR also. The coil is over cooling that bare metal in those spots as its the coldest place. A dew point is being met there. Simple possible fix would be insulating that coil. A shame a full cased coil wasnt used. They look a lot better too, AND the are much easier to work on.
I dread jobs like yours where I feel I have to inspect the coil condition or replace a TXV or something.