I have a sunroom that I like use for cookouts and when we have friends over to watch the game or something. Problem is, it is almost unbearably hot in there at times. Sunday I went and picked up a 5000 BTU window unit and that didn't really do much at all. I exchanged that unit for a 8000 BTU yesterday which made a difference but its still not really cooling in the day time. The room is 260 square feet and the unit is rated for 340. I have a ceiling fan and a/c duct from the central air in the room as well. I am thinking I need something to block out some of the sun coming in. It has 16 windows and two sky lights. I need a cheap idea to help keep some of the heat out that doesn't involve buying blinds for all the windows.

Have you considered tinting the windows. It will help a good deal. You have built a green house in effect. You need to keep some of the sun out to keep it cooler. Shades are nice because you can let it warm in the winter.

Sunrooms need double pane insulated windows. Without the right windows, it can be like an oven. 5000 btu, is only good for 100sq/ft. A 12,000 BTU a/c is what i would do. Would tinting the windows interfere with your views?

Like bucky said, you have basically built a green house. The only way your going to cool it well is to keep sun from reaching the windows or put so massive an AC unit in there it could cool a room at least twice that size.

The best shutters to cool the room would be the Bahama style shutters.

As a builder I often run into the problem of what customers' think is pretty isn't always what works well.

Without adequate insulation and ventilation it is easy to create a hot box. With enough windows in the right location you can have it just right and still have a hot room.

There are really 3 options:

1. Shade the structure
2. Insulate and ventilate the structure
3. Blast it with cold air.

Perhaps a large shade or series of shades on the outside attached to you soffit (south or west wall maybe) to block sunlight from coming in, shading multiple windows and the wall unit at one time. Lower in high sun times, raise at others. Or some type of shutters like you see at the beach. Window tint might help too.

Plant some fast growing ornamental shade trees to block some light.

Better windows: double pane, gas filled, insulated.

Better insulation R factor in attic space (if you have one), walls and ceiling, if possible, depending on construction. Spray foam might be a good application in this setting.

Depending on roof and ceiling construction, consider adding some roof venting (turbine, power fan, ridge vent) along with good soffit venting ratio, if possible.

That along with a window unit should help. From an efficiency standpoint, if you have adequate shade and insulation/ventilation, then the air unit will not have to work as hard for as long to have the room at least satisfactorily comfortable.

Mitsubishi Ductless split! Remote controlled Heat Pump with Inverter!
Buy once, cry once.
The other manufactures look the same but they are not!
12,000 btu installed without electrical in a typical install is 3500.00.
Have someone that knows the product, size it for your application.
Your Welcome!

Yeah a mini split is designed specifically for this type of application. We use Quietside, Mitsubishi are nice too.

I second the mini split suggestion! I have one, and it works wonders! Very energy efficient as well!