During the day, the house is noticeably cooler than the outdoors. I haven't found myself sweating while doing light cleaning on a weekend afternoon. And when I come into the house after working in the garden, it's feels nice and cool--not stuffy.
That's all great, but the true benefit of the insulation comes at night. Previously, the house would feel warm and stuffy in the evenings. Now, it's just as cool as it is outdoors. On previous summer evenings, we would sit in the living room with as few items of clothing on as possible, trying not to sweat. Now, I wear thin sweatpants when relaxing after work. It's that much cooler!
My final piece of evidence is this: We have yet to dig out window air conditioner out of the garage. The insulation is working so well that our bedroom is cool enough to sleep in with just a few open windows and a ceiling fan. The cheapskate in me is delighted by how much we're saving on our energy bills.
So, with all this evidence, I can definitely recommend that everyone upgrade their attic insulation to R-30. The insulation, along with the solar attic fan and our indoor ceiling fans, has really made living in Los Angeles without central air conditioning easy. And even if you do have central air, I'm sure your energy bills will go way down with the new insulation.
HI,
I'm really curious about your cellulose insulation in the house! How has it been in this really cold weather? How was it during that really hot period before Halloween? I live in the highland park area in an old house and want to add insulation too. I also don't want add central AC or use the gas heater. great blog!
The insulation continues to help out with heating and cooling. We barely used the air conditioner this summer, and I think it helps in the winter months as well--although less so. I think the best thing to keep the house warm would be to seal up all our old, leaky windows. That said, the insulation has done a good job of keeping the heat inside the house when we turn on our gas floor heater. It warms up really quickly in the living room and mostly stays warm, even after we turn the heater off.