agstaff Posted January 25, 2010 Report Share Posted January 25, 2010 I've read quite a few of the posts here. I've researched this topic extensively and can't seem to find a definite answer. I've read the tables and performed the calculations. Here is my situation: 80% 66,000 btu fan assisted Bryant furnace, 4' single wall connector, 2 45 elbows, no horizontal runs. 40 gallon water heater, 40,000 btu with natural draft hood, 3' single wall connector, 2 45 elbows, no horizontal runs. Both the furnace and water heater vent through 4" single wall pipe to a 6x5x4 sheet metal wye. The 5" outlet has a 4" reducer that connects to the furnace. The 6" end of the wye then connects to a 6" b vent that travels straight up, no offsets, through a wall chase and through the roof where it terminates, approximately 17'. This is the height to the tallest appliance, the water heater. Approximately 14' of actual 6" b-vent. From all the sizing guidelines I have read, it looks like I should be running a 4" b-vent connector from the furnace and can use a 4" double wall for the common vent up through the roof. I currently have 6" b-vent for my common vent. Will this cause problems with condensation and furnace efficiency? If I'm going to fix it I want to do it right! Thanks for any insite! Quote Link to comment Share on other sites More sharing options...
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.