I'm 30 mi northeast of Atlanta, a mixed climate with roughly 50-50 heating/cooling. I actually will be using the A/C heat, as I will have a desuperheater on the compressor discharge where outlet temps will be around 150F, absorbing the superheat and probably beginning the condensing process. This heat WILL be dumped into the ground-under the slab!
I got a Nordyne (Tappan branded in my case-check out surpluscityliquidators.com!) IQ inverter drive 22 seer outdoor unit with a matched ECM blower air handler. It has a HUGE condenser coil and the indoor unit uses a communicating EXV. The upper 2/3 of the condenser has multiple flow paths, but the bottom third is single pass-I believe they are expecting most of the refrigerant to be condensed by then, getting additional subcooling very close to ambient before it leaves. I plan to put vinyl downspout channels around the bottom third holding a synthetic evaporative (swamp) cooler pad, which will then get sprinkled in the upper channel by the condensate water when it is pumped. This water will dribble down the pad and whatever doesn't evaporate will collect in the lower channel, wetting at least the bottom several inches by capillary action. I will adjust the refrigerant charge so that the final refrigerant condensation happens in the lower third, so the compressor will "see" a condensing temperature that is below ambient.
What happens next depends on ground temps. If the ground loops are significantly lower than that subcooled discharge, I may run the refrigerant through a second HX, but this only helps much if there is still condensing to be done. Instead, I may use groundloop water as a precooler to incoming ERV air/return air through another HX. I don't want to boost fan power draw by too many restrictions though-I will arlready have MERV 4 prefilters and a MERV 14 bag filter, as well as the coil.
Some may ask why didn't I just get an ASHP instead of a straight cool system? The efficiency is 20 SEER/approx 13 EER for the ASHP version instead of 22SEER/14 EER for the straight cool. When cooling, you don't get the heat of compressor work back like you do when running in heating mode. Since I already have efficient heating in the works, maximizing cooling efficiency is paramount. I may even look into an evacuated tube superheater like SednaAire offers. They even use my identical Nordyne unit as their base system! I'm not yet sold that it would help the cause more than using that solar collection space elsewhere. Anyone else have any insights?
The Google Earth pic shows up for me-anyone else having trouble seeing it?
Craig