From project description by TimeFramed:
I've had real trouble with thin walls splitting apart, particularly on larger prints, (a. because they're larger, b. because the take longer to print -- i.e., overnight, and my printer is in an unheated shed).
Figuring the ambient temperature drop at night was the main cause, I decided to get an enclosure heater. And an inexpensive temperature controller. After installing and testing the heater, I found that using as just a radiant heat source was heating the enclosure surfaces near the element too much, so added a low-speed AC cooling fan (on the same relay, so it comes on with the heater. That solved the too-hot-in-one-spot issue, but tended to blow warm air onto one side of the print.
So, I made a cowling that funnels the warm air to the bottom of the enclosure, and to the front and back; to more evenly distribute the air.
The "stripes" you see on my 'top half' part are pieces from the first, horribly split, part glued onto the second print (that faired much better having been printed while using what survived from the first print).
The bottom half printed even better, while using the top half, and raising the extrusion temperature by 4 degrees.
Now I keep the ambient temperature of the enclosure at a toasty 38C.