On Thu, 4 Aug 2011 06:57:55 -0500, "Steve" wrote a bunch of stuff based on insufficient information...
This home also doubles as a home office with a substantial quantity of computer and office equipment scattered all over. What I want is a largely self-regulating system that is bright enough to dynamically overcome variances in heat loads/losses. This includes automatically reconfiguring airflow for the winter heating season so the basement won't be cold.
The main A/C problems are due to office equipment including laser printers. A single computer workstation or server can dump 2000-3000 BTU into a room when it's operating at full tilt. My main 'office' has three such machines in it (soon to be 4) and they idle 99% of the time. A laser printer can rapidly turn a small room into a sauna if you're printing off a binder full of documents. None of these loads are predictable nor constant. I would not want to size any system assuming maximum loads at all times. I'd be freezing my butt off most of the time and have even more mammoth electricity bills than I already do .
Some problems are exacerbated by afternoon sun on south-facing rooms. At least one egregious air flow issue is caused by a defective damper that needs diagnosiing and/or replacement.
None of these problems are solved by having a single thermostat 30ft away on a different floor. A more ideal solution might be to introduce a portable A/C for the 'office' rooms. Unfortunately, condo rules will not allow drilling more holes in exterior walls nor anything that smacks of a 'window' air conditioner.
As for your remarks about 1100CFM, the installer set up the system for
900CFM for the 2-ton A/C unit. I measured 1100CFM out of the registers when the air handler was set to its maximum 1400CFM limit (with A/C disabled).According to the CFM numbers generated by a consumer-grade HVAC program, one small room here needs about a 50% air flow boost if all the equipment in the room is running full tilt. 30% appears to be doable. Under normal circumstances, that room is only 2C higher than the thermostat setpoint. Under equipment load, that differential rises to 6C which makes it near-impossible to work.