Kevin,
Regarding the glass block.
From the IRC.
-
R308.4 Hazardous locations. The following shall be considered specific hazardous locations for the purposes of glazing:
- - Exception:
The following products, materials and uses are exempt from the above hazardous locations:
- - - 10. Glass block panels complying with Section R610.
- SECTION R610
- - GLASS UNIT MASONRY
- - - R610.1 General.
Panels of glass unit masonry located in load-bearing and nonload-bearing exterior and interior walls shall be constructed in accordance with this section.
"My 10 year old system still puts out a 15 dg split"
I've seen 30 year old system putting out a TD of 30 - filter so dirty it looked like a block of wood, coil almost the same - little air flow, high TD, NOT WORKING though.
A 3 year old system? I've seen those with dirty coils - from the time of construction (construction dust) and lack of changing the filters. You were there and I was not, so I have to go with what you say.