Location: Roanoke, VAPhotos of Flue and Chase:http://ift.tt/2tBI2LM is a pretty large chase in our house where the gas water heater flue goes through to get to the roof. The water heater is the only natural gas appliance using this flue, the gas furnace has one of those newer more efficient exhaust systems and vents out via PVC pipe in a different place.This chase has been a pretty big issue for our A/C. The attic is around 109 Degrees F right now (and only getting hotter) and the air just "falls" down this chase, causing heat to radiate through walls, and the hot air to flow through any cracks or crevices in the walls. And the Air return duct also happens to be in this chase, so the system is having to remove extra heat from that as well. So the chase needs to be sealed up and insulated. I have been googling this since yesterday and found this guide:http://ift.tt/2vyyWwI explains that I need to use Aluminum flashing and high temp caulk to seal around the flue, as well as create an "Insulation Dam" around the flue giving 1" clearance between the flue and the insulation. I also found this Reddit thread from which a user, gbgopher, provided very useful and helpful information. With the information they provided, I was able to identify that this flue is definitely a type B vent, as it is stamped on the side, "type B gas vent".http://ift.tt/2tBEV6N is all well and good, and I should be able to proceed with sealing the air leak but there is a concern. There is a lot of surface area around the flue and it's pretty hot to the touch when the water heater is working. Even if I seal up the leak, I feel like the flue will still potentially cause issues and heat up the now closed off space to temps as high as they are now. Of course, this would only happen when the water heater is working so it might not be that bad, but either way, even if it's better (which I'm sure it would be), it's still going to make the A/C work harder than it needs to.Some thoughts that come to mind but would be difficult to pull off are insulating the walls in the chase as best as possible before sealing it off, or possibly constructing a barrier with 2" of clearance that goes around the chase, all the way to the floor and insulating that barrier, then sealing off the chase in the attic...But in addition to these being difficult, I'm not sure what issues they may cause, if they would be safe, or if they would even be feasible (more difficult than I already imagine). I'm not really sure how to proceed with my project at this point. Would either of my suggestions work, should I even worry about it at all? Or is there an even better solution that I'm not thinking of?Thank you very much for your time and help! via /r/DIY http://ift.tt/2vz4B1g
