Greenhouses, Sheds and Sun Rooms - condensation on enclosed porch

I have an aluminum enclosed porch mounted on cement. In the winter when there is a snow melt, it gets much condensation on the roof which causes it to almost appear to be raining inside of it. I remove as much snow as possible but even with a minimal amount on the roof, dripping continues. Is there anything that can be done to prevent this. The porch was probably installed in the 70's. The porch does have electrical outlets, but is unheated.

I would gather from your post that this porch has windows, and that the roof is probably an aluminum flat-pan or v-pan. If both of those assumptions are correct, the easiest fix would be to open a few of the windows. This will allow the room to be approx. the outside temp., and should reduce, if not eliminate the condensation. If keeping the room cold is not an option, or at least not what you desire, then I would look at replacing the roof with 3" Weather Breaker roof panels. These are 3" thick styrofoam, with aluminum skins top and bottom, come in either 24" or 48" widths, in lengths up to 30'.