Ashley Moody is releasing "Scams at a Glance: Keep Your Cool" to ensure you don't get taken advantage of if your A-C is on the fritz. Common scams include a technician claiming parts need to be replaced when nothing is wrong, quoting high prices in an effort to persuade you to buy a new system and selling you an unnecessary amount of refrigerant. She says your best defense is becoming familiar with how HVAC systems operate, getting a second opinion and insisting on a written agreement.