Portable swamp cooler for a garage

We just moved to a new home in Las Vegas and neighbors tell us that we will need a swamp cooler for our garage. The builder says if we put anything through the wall, we will void our home warranty, and we do not have an attic for venting. Do you know if those portable swamp coolers work well, or are there any other alternatives?

 

Is it possible to install a window in the garage? I don't see how that could void the warranty. If possible,then install a window mount cooler. If you can go this route, be sure to give the incoming air a place to escape like a walkin door leading outside slightly open or garage door raised a couple of inches.
A portable will somewhat cool if set in an open walkin doorway in order to pull in outside air. If used in an enclosed space, it will work OK until it raises the humidity in the garage. At that point it's cooling effect will fall off due to it raising the humidity in the garage.
Mike