Extending High Efficiency Furnace Direct Vents
Hi all. Well, it has been a rough winter in Massachusetts and I am looking to install a standby generator. I have the perfect spot for it next to the chimney to tie in to gas and electrical, but the issue is my direct vent furnace pipes (intake and exhaust) are right next to the chimney. The generator tech said that was an easy fix - just extend the vent pipes so they are to code (not within 5 ft. of the generator). There is already about 4 feet of exposed vent pipe, so adding 5 feet will bring it to around 9.
I am not planning on doing this myself, I will have HVAC out, but I like to have a good sense of the situation before I have someone out to do the work. So this is the situation:
It is a Bryant furnace, 40,000 BTUH Model #926TA3040V17
If I’m reading correctly according to the attached chart from the manual, for my 2” pipe and at 0 degrees winter design temp, I can have up to 25 feet of exposed pipe for the vent, as long as it has 3/8 inch insulation.
So, my question is - does anyone have a similar experience? If so, what is the best route to go down for exterior insulation that can withstand the elements, and is aesthetically pleasing?