Your installer just needs to spend a little more time confirming charge and air flow. TXV means he HAS to charge using super heat / sub cool methods. As far as sweating, only an indication that you are too hot.
A good HVAC tech knows how, an educated HVAC tech knows why!
The indoor split is contingent on the humidity level.
If the indoor humidity is high, a 16-F split would be okay.
The normal blower position blows air through the coil, & therefore the only increase in its percentage of normal air pass-through (by-pass) would be due to the increase in velocity & CFM through the indoor coil - with blower door-panel removed.
If the blower is drawing air through the coil, with blower door removed, it could be a near total by-pass of the indoor coil. The TXV would shut the liquid flow way down helping to protect the compressor; a fixed orifice metering device would in a short time, be a major liquid slugging threat to the compressor.
Check duct system for air leaks & check for required airflow, correct CFM if needed, then charge using Subcooling & verify TXV's specified Superheat setting.
Last edited by udarrell; 07-07-2009 at 12:00 PM.
Reason: wording change