My 1988 Carrier's lineset's liquid line would get quite warm to the touch when the temp would reach over ~85, and would be fairly cool when it dipped below 75 (OD temps)
My new Am. Standard 13SEER's lineset's liquid line stays at nearly the same temperature whether the temp is 75 (OD), or 95. Does this indicate the much greater efficiency of the 2006 unit, versus the 1988 unit, or does it indicate something wrong at all?
The system (old and new) was a 2.5 ton A/C only system.
When it recently got very hot - about 97 or so, the lineset finially got warmer, and paridoxically, the supply temp from the ducts got cooler. What issues are at play here?
13 SEER condensers have more coil surface area than lower SEER of same tonnage, hence more capacity for subcooling liquid refer.
Several things could coincide with cooler supply temps/warmer liquid line temp. No real way to nail down what's going on without on-site numbers (superheat/subcooling, delta T, etc.)
Building Physics Rule #1: Hot flows to cold.
Building Physics Rule #2: Higher air pressure moves toward lower air pressure
Building Physics Rule #3: Higher moisture concentration moves toward lower moisture concentration.