Hello stolen thoughts, no space is "lost" in your hard drive. You have 1GB of free space while 28GB of used space, that makes total of 29GB of your hard disk capacity. So, what is lost??

You'll only remove temporary files in certain location manually. To delete unwanted files completely, use ccleaner.
Hibernation does not take "Free space" from your hard disk separately. While it goes to hibernation, it uses your hard disk space to save data temporarily.

I think you're talking about "System Restore" space, which is allocated certain space of hard disk, but is is always a "Used space".

Total Capacity of a hard disk = "Free space" + "Used space" , is true in every case.

Recycle bin is counted as "Used space". It is merely a separate folder. Unless you remove files from recycle bin, it is never deleted.