Revisions log for Answer #2190
This is the answer to the question What is an alternative to blinds on large windows to protect your home from overheating in the summer?
Revision 1
As for your problem: Be grateful to your energy consultant. It saved you from a major construction mistake. An 18-square-foot room with a west-facing window can easily become virtually uninhabitable within six months. Unless you like your living room to be over 30 degrees.
You can forget about air conditioning through KWL, the volume flows are just too low for that.
Cooling through underfloor heating can give you 1-2 degrees more.
As an air conditioner you will need more cooling power. Solar gives about 1 kW per square foot. Even if you subtract 50% because of the angle drop and covered windows, you get about 9 kW. That's a very large furnace at full power!
You only have two real options:
External shading.
A much (!!!) smaller window.