Renovation Work (insulation & AC talk)

[jconnor3]

Not exactly my garage, but I know you guys have a lot of knowledge. I'm converting my attic space from just storage to livable space. Step 1 for this is sistering the current existing 2x6 joists. To do that I needed to remove the T&G subfloor that was down and then the blown-in insulation between the joist.

That has been completed, but we are starting to get warmer weather than usual here in Indiana and we have needed to fire up the AC. Problem is though it seems that with the insulation out of the attic now, my nice cool air is just escaping right out of the house and my AC can barely maintain 75 running constantly. It's an old 1930's home with thick plaster ceilings & walls if that matters.


I thought that if I got more of that hot trapped air out of the attic space it would help keep the main level cool, but i'm not sure thats the right thinking. There are windows in the attic that I keep open and I bought a large metal fan to put up there to get more of the hot air out of the attic, but is there anything else I can do to help? Or do you think that's actually making it worse and I should keep the windows shut and keep in the hot air?

Heat should be coming down soon, but I could be in this holding pattern for the next month or so. Any suggestions?

 

[8mpg]

Spray foam the attic rafters and convert to a sealed attic. I think its the best option. You need some form of insulation from living space (the attic you are converting) and the outside air. Spray foam is the best bet because it has a great air sealing capability. If you dont, you can try lining the rafters with batt insulation and doing air tight drywall. Air leakage is going to kill you.

 

[jconnor3]

Sorry, I should have specified more.

For this attic reno, I am removing 2/3 of the roof, putting up new 7ft walls and then a new roof. So, my current situation of no insulation in the attic floor is temporary until I can demo and frame the new structure. Then I will be insulating the walls and roof and heat/cool the entire space.

But my problem now is getting by until I can blow the roof off and get the new framed in. Is there anything else I can do to remove heat from the attic space other than open the windows and run a fan OR should I close it up and let it be hot up there and maybe I wont have as much air loss in total for the house? I'm just not sure which is a better option.

 

[readhead]

You might want to seal off the stairs and access to the attic so you aren't pulling return air from the attic. Then continue venting the attic. Your attic venting and return air may be fighting each other.

 

[ItsNemo]

If you blow the hot air out, some sort of air needs to come into replace it...unfortunately your conditioned air is the easiest source. If you can, open windows at either end, blow the fan with the natural breeze (don't fight the natural air movement) out one of the windows, and do your best to seal any air movement from below.