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  1. we have an older cottage with no ceiling.just the old open rafters and no insulation in the roof area, the cottage gets real warm in the summer and we try using ceiling fans running in the reverse summer direction but they just drive the warm trapped air down. we are redoing the shingles and would like an opinion as to wheather adding some kind of powered attic vent system that could be controlled might help and then we could run the window AC unit with th colder air actually making a differance as the warm air at the ceiling can be removed. I have considered that simply adding a few roof vents would help a certain amount but we also use a fire place and small heaters when the weather is cool and would not want all the warm air going out the roof. Would love to hear an opinion. we do not expect perfect living conditions but jus to hear might work best.

    • Hi Gary,
      Without the ceiling / roof insulation it’s going to be difficult to condition your cottage. AC is efficient only while recirculating air within some sealed area. Therefore, if you decide to add any roof vents, you’d have to install some type of mechanical dampers so you can close them whenever the AC kicks in. Otherwise you’ll be wasting lots of energy because all that cooled air will be gone through the roof.
      Also make sure that the AC unit is large enough (BTU’s) to cool down the entire space (including your open attic). Combined with the ceiling fan it should condition the entire space quickly but because of the missing insulation, it’s not going to be efficient.
      Roof vent dampers would also help while heating this area / prevent loosing heat. I’m not sure if your fireplace has an exterior combustion air port or it’s using air from within the house. If it is interior air, those future roof vents (if left open while using the fireplace) might cause an excessive draft and result in faster burning of the firewood. Also, if installed in a close proximity to the fireplace chimney, you might get some smoke back to the house.
      So again, a damper equipped vent would help but you may need to improvise since I don’t think they make attic / roof vents with dampers. If you have a gable type roof you can install a gable vent with automatic shutters and control its operation with a switch or a thermostat. Gable would simplify this whole process.

      Thanks and let me know if you have any other questions.

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