92% furnace in older home

Chris Brown_2

Hello,

I own an old house (1884) wood frame with full basement of limestone. It is heated with 2 forced air furnaces, both of which need to be replaced.

I am interested in purchasing the high efficiency furnaces, but not thrilled with the prospect of drilling two holes through the firestop and exterior wall to vent the furnace by PVC piping.

I have a few questions:

1. Can PVC piping be run through an existing chimney to vent (it would be a very long run).

2. The basement windows are very large - and tall. Have you ever heard of anyone venting out of the window, if they were made of glass block? This would be less destructive than going through a side wall.

Thanks for any help you can offer.

Chris

Steve Ebels

You can

Vent up the chimney using it only as a chase. HOWEVER! You must stay within the manufacturers specifications for length,number of elbows and diameter of the vent pipe. The preffered method would be to vent out the ring joist of the house. Why can't a hole be drilled in the sidewall? It would seem to be less destructive than knocking out a block in your window.

Consider using a two stage or modulating boiler and a couple of air handlers instead of the furnaces. That way you could use the same heat source to heat all your domestic hot water also.

Hope this helps

robert griggs

venting thru the window

I would check with your local building department, but here in New Jersey, we are allowed to vent thru a window if it is permanently sealed and cannot be opened. The same restrictions apply to location of the vent outside the house- it must be atleast 4 feet from any door or window. Check with your local building department to make sure before you do this.

corey

Codes

My building inspector here in Mass was ok with venting PVC exhaust through, over or near a basement window as long as it was screwed closed. Glass blocks should be fine too. Depending upon your climate, there may be height requirements to clear snow depths. That is why it is more typical in my neighborhood to go right through the sill. Most homes of that vintage have big beefy sills, and even a 3-inch hole will not compromise them.