All chillers have a pull down rating meaning they will lower the temperature of X gallons, Y degrees at Z flow rate.
If your chiller is sized properly and is in the recommended flow range it will probably lower the temperature 5-7 degrees from whatever high the room reaches provided its not for an extended period of time. If you leave it unattended for many days probably not, over night or maybe two days it should be fine. If it were me I would add a clip on fan blowing across the longest dimension to aid in cooling but it will cause evaporation so the tank may need more frequent top offs. Fans by themselves can easily drop the temp 3-5 degrees or a little more. I sold my 1/4HP chiller a couple years ago as it never ran anymore with proper fan placement and my house is warmer during the day while we are at work.