Carrier Infinity Static Pressure Problem
I just had a new 5 ton 21 SEER Infinity system installed a few weeks ago and had a message on the Infinity Control saying to replace the filter!
I called my installer where he came out and did a static pressure test from the Controller where it read .82. He said this was too high....which from the reading I have absorbed, the optimal system should be around .5.
So the trouble shooting began:
I have an Infinity Air Purifier (GAPA) installed as well and when the filter is removed, the system drops to .42 - is it normal for this media filter to pull .4?
Reinstalled the filter and began removing the return register vents. After doing so, I was able to get a drop of .08 - down to .74.
I had all new ducts installed and supposedly resized correctly for the existing boots/vents. I don't recall any measurements were taken in each of the rooms, but rather based on what ducts were currently ran. For example, I had a 8" duct feeding two 7" ducts going to registers. The duct was resized to a 9" duct going to the 7's.
I would say every supply duct was increased anywhere from 1-3" and have about 8 ducts coming out of plenums. Would too many ducts cause static pressure issues or is this more of an issue on the return air side?
I have three return air ducts - 1 just under the furnace - 18", 2 about 30 - 40 ft away with 14" ducts
BTW - the blower is set at 1750 CFMs..
Very turbulent air flow,at the entry into the filter will incrrease the static.
Please post all model numbers and pics of the indoor unit and connecting ducts.
Your installer obviously missed the mark on the redesign,they'll need to redo some portion of the duct.
If they would take the static of the return and supply separately,controller can't read them,they'll have better idea of where they need to rework the ducts.
Last edited by dash; 07-16-2008 at 04:04 PM.
20 x 25 Infinity air cleaner @ 1800 cfm should be around .19/.20 pd but that doesn't (in my mind anyway) leave alot of room for return duct and grills.