Just moved into a new house and i was wondering if anyone had any information on the fireplace that is in it. The house was built in 1969, but im not sure if the fireplace is original. The thing that is strange is that there are 2 rows of 5 tubes directly above the fire that wrap behind and down into the crawl space where the combine into a duct and then into a fan. The fan is now disconnected but used to blow the heated air into the duct work coming from the furnace. Not sure where the tubes get their cool air from. There is also an ash clean out underneath the fire but that is it. Just wondering if there is anything special i need to know about this type of fireplace?