you'll have fun when temperatures drop near 40 and you start getting messages on your thermostat.

My thermostat has been set at 78 for more than 5 years, with the optional humidity control feature turned off. No mold.

What might cause temperature increase inside a house? Electronics? Lights? Oven? Dryer? The human body?

If you have an ecobee unit, here's a video. Overcool to lower humidity:
https://youtu.be/CcnGqkMWMns

None of those things will have much of an effect. The most effect comes from the outside air temperature and an inadequate amount of insulation and air leaks around windows and doors.

Replace all light bulbs with LEDs, but not for heat. The biggest savings will come from a reduction in electricity usage. An incandescent bulb uses about 6 times the amount of electricity as an LED.

That is a good explanation of the humidity control feature on most thermostats. Today, the outside temperature is 71 and the humidity is 96 percent. An unusual day in The Villages. The humidity inside my house is 68 percent, with no cooling being used at all because the thermostat is set at 78 degrees, which is a comfortable temperature for me. On hotter days, the humidity would be about 40 to 50 percent because the AC would be operating. Do I want to turn on the humidity control feature to try to reduce the humidity to 60 percent? No, because the temperature would drop to about 74 degrees and the house would be too cold. But, it is a personal choice. I have never had a mold issue.

We've been here in a new home since fall of 2019. To get used to the heat and humidity, we got accustomed to home temp set at 77°.

We have Carrier HVAC and Ecobee thermostat.

Only recently, in the last several weeks, have we experienced the AC cooling down the home to below the Ecobee 77° AC setting. Just a degree or two. It's a combination of the humidity control, and an Ecobee automatic software update. To compensate, we upped our home AC setting to 78°. Still quite comfortable to us.

Why ask the question here versus calling an a/c company and save you and us time reading all the responses that may be incorrect - just wondering!

Do you have an AUTO setting? If so, your A/C might be trying to maintain your Heat/AC setting.

Good point. I use the AUTO setting, but my thermostat will not allow the heat and cool temperature settings to be set at closer than 4 degrees apart. So, if the cool setting is 78, the heat setting must be at 74 or below.

Oh I am sorry- I forgot I had the power to FORCE you to not only read a post, but also reply to it.
But looking at your prior posts, it seems like this is your "thing" to nullify other's questions. So the question is- who is actually the one wasting their time- seems to be YOU

Check to see if your AC heating element is kicking on when the temperature drops in your house. Our AC technician told us it is best to turn that option off in settings since it uses huge amounts of electricity and we don't get that cold here in the area.

Pat E
 

Chances are the pan under your AC is not draining. The drain pipes here get clogged with gunk. Look at the pvc pipes in front of the AC. The one sticking up has a cap on it that you can remove. Put your hose on it and turn the hose on low. It should push the mess out. The reason you’re AC turns off is because it has a safety valve on it to keep your pan from overflowing and flooding your house. This should be done once a month to keep the pipes clear

mold can grow behind walls, but, hey, it's your party

Any single stage AC system will control relative humidity by lowing the temperature. However, If you have a staged AC system, the humidity is controlled independent of the AC temperature setting. When a staged AC system is running to control humidity, it has very little effect on the temperature. It runs similar to a dehumidifier. It is one of many advantages of a staged HVAC system