I don't know where else to post this. I apologize in advance. These are pictures of the exhaust vent coming right out of my furnace (oil burning). I think it's the hole where exhaust gas temps were initially tested upon installation. However this is my first home. What I need to know is should this be covered to avoid exhaust gasses into my home? Worried about carbon monoxide poisoning. And if so how do I deal it up? What do I use. It's starting to get pretty cold here and I need to get this in order. Thank you in advance.