Air temp in crawl space seems way to cold in the summer and way too hot in the winter

[Sparky H]

I have a single variable speed system operating 3 zones (added on).   In the Summer, when all zones are operating and all room vents are open, the bypass damper pours  cold AC into the crawl space.   I thought the bypass was only to open up if too much pressure was detected.   So why would it be open. ?  The crawl space seems to be cooler than room temperatures through the home.    Is this normal and what should be expected?

[Marc]

The fact that the vent is open and the zone system is in operation doesn't mean that the electrically operated damper is open. Some could be closed at any point in time, such as when the target temperature is reached, and if too many are closed, it's gonna dump excess air flow into the basement to insure the minimally required mass airflow rate.

[Howard L. Rennie]

Good information.