[silvershot55]

My new 92% efficiency furnace installer says he can put both of the 2 required pipes inside the old chimney, instead of thru a side wall of my 1100 sq ft 26 yr old house in wpg. I have an electric hot water htr. Is this common practice, or OK to do ? thx. much. Want to have it done within days.

 

[hvac benny]

It's ok to do, although if your chimney has an offset inside it may be quite difficult. It's common to do in houses that have the furnace located in an area that is difficult to run the new vents for a high efficiency furnace.

 

[yuri]

It is better to run them out a side wall. If they ever get plugged with snow or iced up nobody wants to go on the roof to unplug therm. -40C and a 50 km wind is not good to be up on a roof in.