gas furnace vent

Sis,

It depends on the furnace. Some vent into a chimney, some use a power venter that is built in that COULD vent through a wall. The ones that use plastic pipe (90%+ Efficiency) are the easiest. You would be best contacting the contractor who installed it. Some that use metal pipe use type B vent which is double walled to keep the outside of the flue pipe cooler. There are code requirements on how close the metal pipes can get to combustible materials. Also sizing and max number of fittings and max length restrictions, even for Plastic, low temp flues. Not often a good DIY project. Different brands, models and sizes are all different.

Stretch

You start with the installation manual for your specific furnace. Different models require different vents. You also need to meet all local codes controlling vents in your area.

I highly recommend that if you have any question at all about how to do this, that you have a professional handle it. It can be deadly to be wrong.

Thanks to both of you for your advice. I don't have a manual, but will look up the manual for my furnace online. Sis

Search google.com for the manufacturer of your furnace. See if they have an installation manual for your furnace on their web site. Or call and ask them. (I keep instruction and installation manuals for everything I purchase.)

Thanks for the help. We keep everything also, but when we bought our house, there was no manual for the furnace. Sis