What are the areas you want to cool, size wise, adjoining spaces that will feed off the next room. A mini-split properly located to provide best circulation will, as you know, provide the comfort and economy. The trick is to use as few as possible while getting the air flow. One on either end of the first floor will take care of the whole place...depending upon air circulation and unit location.
What is there now? I think you do the bedroom and garage with ms, right? How is therest of the house h/c?
I am looking into cooling the downstairs of the house, but I don't plan on replacing the ancient 13 SEER a/c unit until it completely dies. At that point I will probably just replace it with a goodman unit I install myself. I suppose I could fire up the fans I have in every room, but to be a true wimp, it really dries out my eyes. I have cut my power usage more than half, and I am making progress.
my best recommendation is to have new low E windows installed. it made one hell of a difference on my house. during the summer my a/c would run non stop all day and most of the night just to keep the house at 75*. now with the new windows and an extra 6-8" of insulation in the attic the a/c hardly runs at night and only a few min. per hour during the day to keep the house at 68-70*. it isnt a cheap option but it is the least wasteful.
I installed a low E window in my office. My father in law has a window dealership, so I got low E triple pane window for about $210. Its the large window on the bottom left.
I am thinking that it may be a good idea to replace the single pane window on the east side of the house. I never open the solar/blackout insulated blinds during the summer because its so hot over there.
It would probably be about $100 for the window, so maybe I should just replace it anyway. I would really like to get the natural light into the dining room, but the heat is a big negative. I would like to experiment with an awning or something like that to block the direct sunlight.
Does anyone have any experience with the solar screen stuff?
http://www.qualitywindowscreen.com/store/36-x-linear-foot-super-solar-90-solar-screen-fabric-p-484.html
Windows are typically the least cost effective solution to heating or cooling issues. Your first step is air sealing - convective drafts are your worst enemy. After that insulation. Only when those steps are complete should you start to think about other options.
I think my house is pretty well sealed up. I re-caulked all the joints, cracks, and windows last fall when I had the whole house repainted. Its basically just a concrete box, so I am thinking that I should be looking for ways to reduce the solar exposure on the house.
The sun comes up in the summer and bakes the side of the house, which is a big reason that I added the mini-split to the bedroom. Its made a major difference in comfort for sure because it starts to get really hot around 6 am.
One other trick - CFL or LED (though they aren't really cost effective) light bulbs - they put out much less heat (that you then need to cool) than regular bulbs.
I think I already picked that low hanging fruit. The only incandescent bulbs in my house are the dim-able light over the breakfast table and the lamp on the wife's nightstand. I have LED outdoor house lights, and am planning on replacing the landscape lighting with LEDs eventually, but I rarely run those.
The rest of the house has the cool blue looking CFL or regular T8 bulbs.
