That one 100 degree week in Phoenix made me rethink everything about my AC habits

Last July we had that stretch where it hit 115 for a week straight. I usually keep my thermostat at 78 and just deal with it. But that week my unit ran nonstop and still couldn't keep up past 82 inside. Figured out my attic insulation was basically useless. Took a Saturday to roll out some R-30 batts up there. Cost me about $200 but the next week my AC actually cycled off for the first time in days. Anyone else have a heatwave moment that forced them to fix something they'd been ignoring?

3 comments

3 Comments

rubys8029d ago

Fair enough but I'm gonna push back here. Adding more insulation can actually trap heat in your walls if your house isn't properly air sealed first, and @taraanderson didn't mention checking for gaps or leaks before blowing that cellulose in. My buddy did the same thing last year and his upstairs got stuffier because the heat had nowhere to go but into the living space. Plus that $400 spent might take three summers to earn back if your electric rates are low like mine at 9 cents per kwh. Not saying it's never worth it but that 115 week made plenty of people panic spend money on stuff that only helped a few degrees.

morgan89829d ago

rubys80 brings up a good point about air sealing, I actually saw a YouTube video that tested this exact thing and they found the attic floor was leaking more air through the gaps than through the insulation itself. The guy doing the test used a thermal camera and you could see the cold air just pouring out around the light fixtures and plumbing vents. I think if someone is gonna go through the trouble of adding insulation, they should spend the extra afternoon sealing those spots too. Otherwise you're just putting a hat on while your shirt has holes in it lol.

taraanderson29d ago

That 115 degree week you're talking about is exactly why I finally broke down and checked my attic too. Turns out my previous insulation was maybe R-11 at best and probably installed when my house was built in the 70s. I went with blown-in cellulose from Lowe's, rented the machine for free, and spent about $400 to bring it up to R-38. My AC stopped running from 2pm to 6pm solid like it used to and actually cuts off every 20 minutes now. The power bill dropped almost 40 bucks that first month even with the heatwave still going. Made me realize I'd been paying for cold air to just escape right through the roof for years.