cool a garden room using a swamp cooler,
 

Ron, Would it be a good idea to cool a garden room that has good ventilation using a swamp cooler, or would that raise the humidity too much? (the area I live in has a dry climate)

In order for a swamp cooler to work the dew point has to be around 60. and then will only lower your temperature 10 degrees. Check your local dew point before you waste your time. You might not have one where you live.