Fixing What's Actually Wrong
Think about it: your AC and furnace push air through ducts in your attic where it's 140 degrees in summer. Electricians walk on them. Cable guys kick them aside. Pest control guys crawl over them. Stuff gets disconnected. Flex duct gets crushed. Tape fails after 15 years.
We crawl around up there (not fun, but that's the job) and find where you're losing conditioned air. Last month in Tropico we found a duct that was completely disconnected from the main trunk - homeowner had been cooling his attic for probably 5 years straight. His energy bills dropped noticeably after we reconnected it.