Hi, I recently to get an old fireplace up and running. It's a brick and
mortar fireplace with a newly installed gas log set in it. Prior to
installing the gas logs, I had the flue closed up to keep the cold air
out. Once I opened it, I got cold air coming into the house.

I'm a little concerned that the air is going in the wrong direction,
especially if it gets windy (we get a lot of strong wind in my area).
It doesn't seem like a strong draft, but it's enough to get me
concerned about the chimney not doing its job correctly.

I went on the roof and looked at the chimney. I noticed that there was
no cap on it, whereas just about every other chimney that I could see
from my roof had one.

I looked down the chimney, and it was clean. There's no cracks or
anything I could see in the chimney inside or outside the chimney
itself.

The chimney is on the side of the house where the roof is at its lowest
point. There is nothing blocking the chimney in the wind's path...no
rooftop, no trees, nothing.

My question is, should I install a cap on the chimney? I would think
this would do the job, but I would like to get some advice before I
tinker with something I don't know much about.