Installed R-60 insulation in attic… now using AC more than before
I had R60 blown into my 1000sqft attic where there was previously only about R11. Baffles were installed in almost every roof rafter. Air sealing of attic floor was performed. This is a low pitch asphalt shingled hip roof over the whole house.
As expected, the temperature in the house doesn’t fluctuate as much. However, I feel as if I’m using A/C more. Before the R60, the A/C would be on when it’s 80+ degrees out. Now I’m using it even when it’s low 70s outside because the house refuses to budge in temperature when trying to “air” it out by cracking some windows open. For example, daytime temp can be 85 degrees, and the A/C cools it down to 78 degrees. Overnight the outside temperature might by 70 degrees, and after leaving windows open all night, I wake up to the stat saying it’s 79 degrees.
What explains this? I have a hunch maybe I don’t have enough attic ventilation so all that hot mass stored in the insulation just releases itself instead of ventilating outside. I have 8 soffit vents and 2 turtle vents at the top of the roof. Do I need more?