Cooling and heating are not one service with two names. They peak six months apart, they are bought by people in two different states of mind, and they convert on two different landing pages. Run them as one campaign and the August budget quietly funds January keywords nobody is searching, then January inherits ad copy written for a heat wave. Split them and each one gets its own budget, its own headline and its own seasonal ramp.
The other split that matters is repair against replacement. A homeowner searching at eleven at night with no air conditioning is not shopping. They want a truck, tonight, and they will call the first business that looks like it answers the phone. The person pricing a new system is doing the opposite: three quotes, a week of thinking, a spouse to convince. Same trade, same trucks, opposite ads. The replacement campaign earns a financing line and a rebate mention. The emergency campaign earns a phone number and hours.