Someone, somewhere probably gave you some bad information, which is why you may have some bad habits.
Here are three things you need to stop doing in July:
#1 Stop Watering Grass at Night
Running the sprinklers late at night might seem smart, since it's cool and you're less likely to soak dog walkers. But without sun to dry grass, water clings, encouraging fungal growth. Instead, water your lawn in the morning when the air is still cool, and the sun's on its way.
#2 Stop Closing Vents in Unused Rooms
It seems so logical: If you close the vents (or doors) to rooms you're not using, you won't have to pay to cool those rooms. But alas, your HVAC will work just as hard, no matter how many vents are open. You may even wind up throwing the whole system off-balance, decreasing efficiency and costing you more money.
#3 Stop Using String Mops
Use microfiber mops; they're cleaner! One study of health care facilities (where clean really counts) showed disinfectant cleaner applied with string mops only reduces microbial levels by 68%, compared to microfiber mops at 95%. Those stats are worth a mop swap.