Attic venting, air sealing, and insulation
I’ve read on here various recommendations on attic insulating, conditioning, venting, etc. Please correct me, but my interpretation of the results is that if you have ridge vents, then gable vents should be sealed due to airflow patterns. Also, an attic fan is proven to more costly than beneficial (climate zone dependent?).
The roof was replaced a few years ago on the house I recently purchased, and although I don’t know for sure it looks as though they added the ridge vents at that time. The gable vents are still open, and poorly sealed I might add. I was going to do some repairs and fix them up, but upon research it appears sealing them is proper (and easier tbh).
This then leads me to the attic fan. It’s relatively new (probably when the roof was done) and I’ve set the temperature fairly high on it. Obviously if I seal up the gable vents, it’s a no brainer to remove. However the fan also has a humistat setting in which I set at 35-40ish% (I think). I’ve heard it running a few times since then, so my main concern with sealing the gable vents is that humidity will build. But perhaps those vents are the reason!
If it helps for best course of action, I will explain my plans for the future improvements in the attic:
– install vent baffles for the first few feet of roof decking from the soffits
– complete the rest of the roof under the trusses with foil barrier up to the ridge vent
– reinforce insulation R-value. current blow in is old and settled. will need to remove some. plan to relocate blow in stuff from the middle of truss over to the sides towards the soffits to make thicker, then lay osb flooring along the middle and lay thick batt insulation on top so I can remove more easily when accessing the attic in the future.
– while doing the insulation, air seal fixtures on the top side of ceiling
– and hopefully remove all of the ducting from the attic in order to run a ductless mini split throughout the 2nd floor to improve hvac efficiency. running duct through walls will be too difficult. Worst case I’ll build casing around the existing ducts to insulate better.
The goal isn’t to necessarily fully condition the space, but more so to manage climate extremes. HVAC inefficiencies are super noticeably at the moment.
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