Hi. I didn't see this last post until now and I am sorry I did not answer your question right away. I usually don't do 'hit and run' postings. You image hosted pics are gone now and I do not remember exactly what your AC unit/garden looked like. I don't know how to post pictures so I can't post mine but I will try to describe it. My AC is at the corner of my house, so two sides were within view and one side was against the house and the far side was against the neighbors yard. I got two, tall trellis and just put one in front of the AC and one along the side. The trellis are at right angles to each other. I didn't care about the view from my neighbors yard. If I did, I suppose I could have added a third trellis and made a "U" shape out of them, going all around the AC unit, but I didn't want it to look like I had a tall 'box' in my yard growing vines. If my neighbors don't like looking at my AC unit, they can put up a fence. LOL. I have them far enough away from the AC unit to let air go around and the vines hide everything - clematis on one trellis and morning glory on the other give different bloom times. Using a TALL trellis makes the viewer's eyes draw up. If one uses a short 36" high fence or trellis it tends to make the viewer wonders what is behind it. Also one can usually look over a short one and see the top of the AC unit. A short trellis LOOKS like you are hiding something. The height doesn't "fit" with any design plan. A tall trellis looks more like it was put there to add beauty. Nearby, in another garden bed, on the other side of the walkway, I have a pyarmid trellis, also with morninglories. This unifies things and makes it look like a 'plan'. I also have another flat trellis on the other side of my yard near the garage, but not against it, that I grow climbing nastutians on. Right now I have a low wide trellis with vines hiding my garbage can and I am thinking about going with a tall one maybe. If I remember your pics correctly you have and AC unit in the corner of your yard near a fence. You could put one trellis on say 'side A' and in front of 'side B', leaving alone sides 'C and D' that are facing the fence. For balance, plant a couple low growing things in front of the trellis so that it blends and flows with the rest of your garden planting. Maybe add some statuary nearby or put another trellis somewhere in you yard to make your AC unit trellis look like part of an overall plan. I hope I was able to make things clear and convey how my trellis thing works. It is hard to describe in words something that pic would show. I gotta get me one of those digital cameras and teach my old self how to use it. :)

If you believe that the air is moving sufficiently inside let's check the outside unit. 1. First feel the air coming out of the unit. You should feel heat being removed from the house. 2. Next look at the 2 freon lines - there will be a big one and a little one. The little one may be very hot so be careful. The big one is the low pressure side and on normal conditions where the pipe is exposed should be cold a sweaty. From this big line you can tell alot.(you will have to find a place where the insulation is off or right where it goes into the outside unit) 3. If it is frosted up then go to 4 if not go to 5. 4. This could be due to either insufficient air flow across the coils of the inside unit or low freon which will cause the coil to start freezing. If there is frost, cut the unit off at the thermostat by switching the heat/cool switch to off and turn the fan switch from auto to on. This will cause the fan to continue running and turn off the compressor outside. Leave it this way for a minimum of 30 minutes. See if you notice the air flow to improve coming out of the vents. While it is off you can check your air filters and make sure they are clean. Replace if necessary. Later turn the A/C thermostat back to cool. Notice if it cools better and monitor the big line. If after about five minutes the line is cool to cold then the freon level may be OK and you should feel hot air coming out of the unit. If it is only barely cool or not cool the unit is probably low on freon. 5. If the big line is not cool and the little line is not warm then either you are very low on freon or your compressor isn't running. Either way you will need to get an AC repairman for repairs.

I know nothing about why your home is not set up for central air. I can speak knowledgeably about split a/c units. We installed them when we lived in Thailand. They are remarkable, in that they usually feature a dehumidify setting, to get the moisture out without making it too cold, as well as a cooling setting. If they worked at 17 degrees from the equator during monsoon season and hot dry season they ought to work well in Washington state. We went with small units in each bedroom, so that we were only cooling the area we were in, and one larger 20kbtu unit for the entire downstairs.

2 separate units will do the job, but cost of maintenance and break downs of 2 units as opposed to one with zone controls will in the long run be more costly. You have 2 units to maintain, you have 2 units to repair when they break. Tag team event. One system breaks down one month. The other system breaks down the next month. Doesn't always happen this way... but it could. zoning has to be done right. So what does that cost? I don't know I am not there. 'Design, Design, Design' other wise 'Trouble, Trouble, Trouble'.