Okay, so best way is to shut of the guest OS then export as OVF, correct? What do you mean by manual process? Does it mean I have to manually create the OVF instead of schedule and automatic creating the file?
With the Export to OVF option, the VM would have to be powered off first. Then you would export it from within the vSphere Client. There is really no way to schedule this.
The free version of ESXi is also limited in regard to the backup APIs. If you have a licensed version of ESXi, then you might be able to leverage 3rd-praty software to get scheduled/automated backups. You might also want to look at ghettoVCB.sh - Free alternative for backing up VM's for ESX(i) 3.5, 4.x & 5.x