By Jim Gentry from Galveston, Texas on December 26, 2012
Why do I have to change the roof jack bonnet when I install a new draft-induced 80% natural gas furnace?
By Customer Service on December 26, 2012
Answer:Every chimney system must use an appropriately-sized roof flashing/roof jack that is made for the particular type and size of pipe for proper UL listing.
By Kevin Bebout from Western KY on January 4, 2013
Below are the specifications for a tankless hot water heater. I am installing two of these inside the mechanical room of a residence. I need the best way to vent these appliances, either separately or together. It would be best to bring the vents together in the attic space and only have a single hole in the roof.
Natural Gas Model Number: PH-24M-DN
LP Gas Model Number: PH-24M-DP
Rated Gas Input (BTUs/Hr.): Full 178,500, Minimum 37,700
Dimensions (inches): 40-3/4 x 18-3/4 x 14-7/8
Empty Net Weight: 76 lbs.
Minimum Working Water Pressure: Minimum 2.4 P.S.I.; Full 12.9 P.S.I.
Atmospherically Vented using "B" vent
3/4" NPT Female
3/4" NPT Male
Hot water output degree rise (U.S. gal/min)
60-degree F Rise
70-degree F Rise
0.75 ~ 1.17
80-degree F Rise
0.65 ~ 3.17
90-degree F Rise
0.58 ~ 3.17
100-degree F Rise
0.52 ~ 2.85
By Tyler on January 4, 2013
You need 7" inner diameter B-vent pipe for your heaters, and we do carry Metal-Fab's 7" B-vent pipe:
Metal-Fab Type B Round Chimney Pipe Length - 7" x 48"
You would need to use elbows and tees to connect the venting for both heaters and then run the pipe out through the roof. To see all of our 7" diameter Type B vent pipe, please see this page: Type B Vent Pipe