While Clethra probably doesn't make a good screen, I like it as a shrub in the right area. I have it in a mixed shrub border and along the edge of a wetland area. Right now it's a beautiful clear yellow. I have 'Ruby Spice' and it's quite slow growing in its current settings, which have poor sandy soil underlain by clay that keeps it moist. From cuttings after about 10 years it's 3'-4' tall in full sun. You may get more ideas as far as solutions to your problem if you post photos of the area taken from the most common viewing points. I don't currently have a feel for the size or shape or type of shade of the area. Are there overhanging trees or closely adjacent buildings that make it really dense shade? Or is it relatively open other than the house to the south of the area, creating a brighter shade with reflected light in the area you want to plant? I honestly think that you should consider a non-growing screen with plants in front of it. That will block the sight of the air conditioner, and you can plant a combination of shrubs and flowering shade perennials in front of it to distract from the lattice or fence without having to worry about density and height. It will give you more flexibility as far as what you plant since there aren't many shrubs that will both grow densely in shade and be resistant to deer. Here is a thread from the GW Perennials Forum that shows the type of thing I am suggesting, though the screen itself could be denser that WoodyOak's current one. Sometimes having something nice to look at close up is enough to distract from the problem area, and layering is often more effective than a single row of plants. For instance, would a small tree close to the raised deck give enough screening from that vantage point? IME Ilex glabra doesn't grow particularly densely, but might be OK in combination with a fence-type screen. I don't know how deer resistant they are, however, since my deer prefer to stay away from where people are. The more common prickly leafed evergreen Ilex are eaten by deer IME. Toxic plants such as the tall shade-tolerant perennials monkshood/Aconitum and foxglove/Digitalis will be left alone by deer due to the toxicity.

The house faces north, and this is the side yard, so the fence runs perpendicular to the front of the home. Fence (chain link)is on the west side of the home. It separates us from a next-door neighbor. I'll observe the sun...I have been so far. I'm fine with the height continuing the grow above 15 ft. I'm using the 15 ft as a measurement where the tree may start to slow down its growth, not stop growing...I know they will grow perpetually. I just don't want to put something with a listed height of 30 or 60 feet, as that implies it will get there before slowing down. Otherwise, why would anyone care about a height measurement at all? So, pruning the height is not a concern to me. Pruning the width may become a concern if the tree encroaches on my 11-12' area between the fence and the house thereby preventing the ability to walk through the area. I'm looking for privacy when in the yard too, as the kids may still play in that narrow area...don't need the crazy dude watching them constantly. We can put blinds in our windows for interior privacy. Thanks!

You have a valid point, Worthy. However, please allow me describe our site. Although it does appear to be a vast countryside, it's really a new very small waterfront development. We are 1 of 3 homes. Don't know when, but eventually we will have neighbors (hopefully nice neighbors ( : . So most of the views will be toward the river, which can be seen left side of the photo. If you look, you'll see blue in the background. The room behind those windows is my studio/work space. You are right, there are views to enjoy outside those windows, too. But there are so many other rooms to enjoys views from too. I appreciate your comments. Gave me more to think about. Thank you very much, Yvonne.

Thanks for the suggestions! We have Oleanders to hide the houses on the sides (very residential neighborhood). We are trying to shake things up with something different (also, I am not a big fan of Oleander with no flowers during winter time). But it's definitely a great option to keep in mind, thank you! The palm you are referring to requires a lot of maintenance, it needs to be professionally trimmed once every two years, and sprayed against the Red Palm Weevil (some kind of beetle that came from Asia to Europe and eats and kills that breed of palm trees) every 6 to 8 weeks. Treatment cost roughly 10 to 20€ per tree and the grooming can be very pricy (last year we paid about 500€ for the big one you see in the pic and 4 small ones). Also, once it grows, the only way to control its growth is to remove it. We are keeping this one and going to keep 2-3 of the ones we have but we are actually in the process of removing some.