I'm a new member but have been monitoring the forum for information that would apply to my situation. I'll try to post enough information without just running on.
I was an owner/builder of my house and contracted to a local HVAC installer for my Carrier Infinity Hybrid system. Some system details:
Heat pump: Model # 25HNA660A003
Furnace (propane): Model # 58CVX110-1-22
Inside Coil: ADP M-215
The unit had high static pressure messages (around 1.3"WC) since it was installed. My main problem was in heat pump mode. The system would start heating on low stage, switch to high stage when it determined necessary, stage back down to low stage due to excess static pressure, then switch to the propane furnace because the heat pump couldn't meet the heating demand in low stage. I used a lot of propane my first year. I have since locked out the furnace until it gets to 30 degrees. This keeps it in heat pump mode but running on low stage most of the time.
My original installer (not an authorized Carrier dealer) gave up and told me to get an estimate from another company to fix it (he paid me the estimated amount with the agreement that he is done). I hired an authorized Carrier dealer to fix the problem. He enlarged/installed some more ducting and got the pressure down to about 1.1"WC. However, from everything I have read on this forum, this is still way too high. The target should be 0.5"WC and anything at or above 0.8 is too high. The new installer is implying that once he gets to 1"WC the system is good. Is this correct or should I hold my ground? The problem I have is a can't find any Carrier literature that states what an acceptable static pressure should be for my system, is there anything out there? The air delivery table in furnace installation manual does list 0-1.0"WC as the external static pressure range.
Thanks in advance for any help.