Hello, new forum member here! I live in the top floor of a new construction triple-decker in Boston with a flat rubber roof. Last winter we experienced several water spots on our ceiling in multiple places (including a large one in our kitchen -- see below), which we suspect were due to condensation in the space between our ceiling and the roof. The challenge is that we have no easy way to access that space, and the only glimpse we've gotten so far has been by removing a small light fixture, recording a cell phone video, and planting a bluetooth temperature/humidy sensor to collect some data. Here is what we know at this point: [LIST] [*]There is ~10" of blown insulation in the space, with ~12" of air gap to the roof (unclear whether or not there is additional insulation under the rubber membrane) [*]There does not seem to be ANY roof ventilation (soffit, turbine, or otherwise) [*]Sensor readings show very high humidity in the space (60%-80% over the past month), compared to an average of ~40% in the living space, and large temperature variations that mimic outdoor temps (high of ~80 degrees F, low of ~25 degrees F this past month) [*]We see an immediate increase in both humidity and temperature in the "attic" space whenever we turn on the heat (maybe duct leakage?) [*]The water spots last year occurred after running the AC for the first time after the winter season (in March, I believe) [*]Our Carrier HVAC unit sits on the roof (near where the large water mark had appeared in the kitchen). An inspector came by last Spring and installed a condensate trap, which was missing [/LIST]Given the clues above, my instinct is that roof ventilation may be the core problem (although I have no idea how the building could have passed inspection in 2016 without it). That said, the spike in temp and humidity when the heat is turned on seems to indicate a potential HVAC issue as well. Any theories as to what might be going on here, or at least recommendations for where to start?

I am renting an apartment that has an electric fireplace and electric heat. There are 5 inch vents from the living room, and the bedroom to the outside. Can someone tell me what the purpose of these vents is? Will there be any problems if I block them off for the winter? Cold air comes in through the vents.