High temp, low humidity - ice cube solution?

I have a small cupboard op with 1 plant currently in it's vegetative state. The setup, and stealth factors don't allow for any significant exhaust/intake system. So basically I just place a big fan, a few feet in front of the open cupboard here and there to allow some circulation. The plant does currently look very healthy, but I'd like to optimize the growing conditions. Right now the average temperature is from 27-30C..and I have to use the fan quite often, with the cupboard doors open, to keep it from going above 30C...The problem with the doors open/fan always running is that it reduces my humidity greatly..to an average of 24-29%. The area with the plant does not have enough to room to hold a vicks cool mist humidifier; which normally would be ideal in this situation. I've done the old add wet towels, and bowls of water to add humidity. I was thinking of a new method to keep the temp cool and raise the humidity a tad. Let me know what you think. Adding ice cube trays? Do you guys think it would slightly increase humidity, while only slightly decreasing the temp. Which would be ideal in my situation. Thanks for your opinions.

peace

I actually did this with mixed results. I froze RO water into ice cubes, and when it was time to water I would just throw a few of them in the box and let them melt. If your air is static, meaning no movement, it helps a little. Maybe a few degrees and about 5% rise in humidity. The best way is to get a small fan inside the grow room, even one that would just run on AA batteries would be fine. as long as it can get that hot air moving past the ice, it will lower temps more efficiently and do a better job of maintaining humidity. Honestly if your having to open the box every so often I would just invest in some ventilation, its gonna save you a headache now and will go a long way in reducing the smell later.

good luck, let me know what you end up doing.