Here is the original item:
Although fans blew in every room,
(A) Faye
found the house unbearably hot.
(B) And wished
that the air conditioning repairman,
(C) who was
already three hours late, would pull into her driveway.
You wanted to do this:
Although fans blew in every room. Faye found
the house unbearably hot. And wished that the air conditioning repairman,
who was already three hours late, would pull into her driveway.
Adding a period after room will make Although fans blew in every room a fragment.
You might want to review the rules.