Question: Hi - I have no experience with gas logs, but my son recently bought a home that already had propane gas logs installed. The seller left no manuals behind, he has not been able to get in touch with her, and we can't find a manufacturer's name/model # on the logs. Is there a reliable way we can determine whether they are a vented or unvented model? Thanks. Answer: There should be a label attached. If not, you'd have to have someone familiar with the products (like a chimney sweep or stove shop) look at them. If there is a lot of soot on the logs, chances are that they are vented. If they are more than 3-4 years old, they are almost surely vented. If the logs are easily repositioned and moved around, then they are also most likely vented...same if they have a good-looking yellow flame - another indication of a vented set. Best to use them with the damper open fully until more is found out.