Insulating a crawl space: walls and/or ceiling?
I've read through many posts on this but wanted to post with my specific information.
I'm in the northeast
Just moved into the home
Home is 40 years old with a 20 year old addition that created a crawl space that's about 40' x 5 or 6'.
Crawl space is cinderblocks and (knock-on-wood) has so far been very dry.
Crawl space has 3 vents to the outside which are as closed as they can be but let in a lot of cold air.
Between the crawl space and original basement are the 2 original casement windows (which we keep closed) and a full size, well-sealed, door.
The main basement area has a powerful Sante Fe dehumidifier.
Above the crawl space is our kitchen which gets freezing the winter.
I've been told various things by various people (insulation companies, basement companies, contractors...) and wanted to get some opinions here on the following:
1. Should I permanently close off the 3 vents in the crawl space?
2. Should I insulate the walls of the crawl space?
3. Should I insulate the ceiling of the crawl space?
I've been told basically the opposite on all of these questions: yes close the vents they are not necessary, no don't close them as you need the airflow. insulate the walls of the crawl space since if you insulate just the ceiling it will drop the temperature of the crawl space and could freeze my pipes, insulate just the ceiling as that will warm up the kitchen and won't affect the crawl space, etc...
Thanks for your help!