The United States is a big place and the climates are all so different.
The temperature can be wildly different on any given day. One Christmas there was a one hundred degree difference between my house and the in-laws’ house. They had their heater on just to stay warm while I was having ice cream and kicking the thermostat down a few degrees. It’s amazing that I could be calling for an air conditioning repair technician to come repair a broken AC at the same time that somebody could be calling a different HVAC service company to help get the heat working in the same country. Some places have four seasons, times when you need your heater or radiator to be in peak form and times when you may never even turn the thermostat on. Other places, like where I live, you have hot weather and the AC stays on ten months out of the year. We might turn our heat on for two months. Around here, HVAC companies stay busy trying to keep old air conditioning units running for as long as possible. Then they spend the rest of their time installing new HVAC systems. I like to travel around the US and see the difference. I was in a place where nobody had central heating and air. Every house had something they kept calling “swamp coolers” to keep the house comfortable. If they replaced my HVAC with a swamp cooler, I think I would end up melting! Even on Christmas!