I'm zone 7b in Atlanta, similar to you. I have a 12'x16' greenhouse, so I can maybe give you the benefit of what I have experienced. I have found that cooling in the summer is a far bigger challenge than heating. By providing excellent ventilation and using 60% shade cloth I was able to match my inside temps with the outside. For my orchids, I wanted to try and keep the max under 90 degrees. After getting lots of advice, I settled on adding an overhead misting system. It does a pretty good job of bringing down the temps by 7 degrees, even on the higher humidity days. For me, this accomplished exactly what I needed. Although your larger greenhouse allows more options, I doubt that you are going to be able to achieve temps in the 70's with any practical system on humid summer days that get into the 90's, let alone 100 degrees. Good luck!

moonsoon first and foremost, as said in my previous post, you need a load calculation in writing broken out by each zone. I believe 10.5 tons is grossly oversized. EACs refer to electronic air cleaners which I believe the GAPA is Carrier's model. You need some type of air cleaner for both systems. EACs are not a cure for asthmatics but may help. Don't know about the GAPA model but most require regular cleaning/maintenance and do produce a small amount of ozone. I would not have one personally. I have a 5" pleated media filter that I change once a year. I lean toward the KISS system(keep it simple stupid!). No offense intended. The "return" air recirculates your inside air. It has to be sized to be in balance with your "supply" air. For example, if you have a 4 ton blower, your ductwork system should be sized accordingly-1600 CFMs both supply air and return air. One large return such as listed in your original post with such a large space will give poor airflow/exchange and most likely will be noisy. That was the reason for my suggestion for another return. And definitely don't place it in a living area-they should be centrally located in your home normally in an inside hallway. again I know that electric rate is not correct but I will not beat a dead horse. I do think a homeowner should have an apprx idea of their utility rates. what are the tier electric rates? I don't have a strong opinion on UV lights. Most homes don't have them and I would think they would be better indicated for areas with high relative humidity or to focus on specific problems with your evap coil. You do want Carrier's tin plated coil not the copper models. as far as ductwork, metal main trunk lines that are insulated with flex for supply and returns would be my choice. check with county building office and see what code is for new construction. IMO

Either you have a bad sensor,wiring problem, or the wires are on the wrong leads, or Its not calling for humidity

Hi Rick, Thank you for your comment! You are correct; rotation sensing isn't something we have implemented at the moment. I can think of a couple of ways that we can accomodate a setup like this, for instance using a magnet mounted on the rotating part. This magnet triggers a sensor every time it passes by, resetting a user defined counter. This way we can simply trigger an alarm that goes off when the counter runs out. Out of interest, can you please provide me with some more information (or even pictures) of your volksgarden? I am really curious about the exact setup as i haven't encountered a rotating growing setup in real life yet. I will consult with the hardware developer to see if we can build a test setup sometime and see if this works as i imagine. We won't be able to implement it right away, but i think this is a really nice feature to implement as soon as we have the chance, as there are indeed no other systems that offer this function.