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.
Thanks for the prompt, if somewhat disheartening, response.
It's hard to believe that nobody in this world has addressed this for
a residential setting. (Any Honeywell business development manager
out there interested in a new niche market?) It sounds like it
should be just a more intelligent version of existing zoning systems
for larger residences. Instead of a dumb on/off switch for each zone,
you have, say, 256 output positions for the damper. Installation and
setup costs would obviously be higher.
Again, the simplest solution is a mini-split. the better units
have inverter control and individual room thermostats, allowing
the system to put "just the right amount" of cooling into
With your specific situation, where you've already gotten a
traditional installation, you might ask an HVAC rep about
a single room mini split, and just place it in your
As one example, the Sanyo 12KHS71 [a] will adjust its
output from 3,000 to 11,900 BTU/hr
- that unit is a heat pump, which will also, duh, provide heat...
Just chosen for illustration as it's one of the 120V AC versions.
Knowledge may be power, but communications is the key
I am an ex-Honeyweller. When I read your OP, first thing I thought was
application by intelligent control,er managed by micro processors or
dedicated PC, probably run on Linux OS and bunch of ATD, DTA interface
controlling all the parameters on every level of the place. Just mind
boggling wish list. After initial commissioning, it'll have to go thru
revision after revision until it really performs as wished. Do you have
unlimited resources?(time and material)
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