Venting question

[tmd]

I just purchased a Fireplacextrordinair 31DVI/32 gas inset. I have a brick fireplace with approx 30 feet of chimney.

Two questions.

1) the dealer is telling me that when they install the flexible pipes, they run the vent pipe all the way up to the top of the chimney attached to a cap. The intake pipe they are telling me that they run the intake pipe up 7 or 8 feet into the chimney. In other words, They are not running the intake to the top of the chimney. They will use insulating blanket etc, to keep air from going up the chimney from the interior room.

They say that they have less problems/issues by doing it this way. What do you think about this arrangement? Should I let them do this or insist that they run both intake and exhaust to the top of the chimney capped off with the proper cap???

2) I already have one four inch flexible pipe that is installed all the way to the tip of the chimney. If they were only going to go up 7-8 feet with the intake, could I use the existing 4 inch flex pipe or would this screw up everything? Also, if I could use the four inch, they are saying that it would void the warranty? Is this true????

Thanks in advance!

 

[Fsappo]

I have only ever done the double 3" liners for DV gas inserts. I have heard of the other method, never bothered to try, because of the "if it aint broke don't fix it" approach. I do recall it being discussed. Manual says to do it either way, providing a block of plate is installed.

I'd ask the dealer what issues they avoid by not bringing combustion air to the top.