I WORK FOR A HVAC CONTRACTOR, AND WE INSTALLED A 90% (CONDENSING) GAS FURNACE IN AN UNCONDITIONED ATTIC. THE EXISTING 80% (NON-CONDENSING) FURNACE DRAINED OUT THE GABLE WALL. THE GABLE WALL IS NOT A SUITABLE PLACE FOR THE 90% TO DRAIN BECAUSE IT PRODUCES CONDENSATION YEAR ROUND AND IN THIS CLIMATE WILL FREEZE AND CAUSE ENDLESS HEADACHES FOR BOTH US AND THE CUSTOMER. WE LOCATED A CAST IRON VENT PIPE IN THE KNEE WALL WHICH WE COULD DRAIN TO IF WE CAN PENETRATE THE PIPE.THE SPACE IN WHICH THE PIPE IS LOCATED IS TOO SMALL TO CUT THE PIPE WITH THE NORMAL CAST CUTTING TOOLS. WE TALKED TO A PLUMBER, WHO TOLD US ABOUT A SADDLE WE COULD BUY AT A HARDWARE STORE THAT WOULD BOLT TO THE PIPE AND SEAL WITH A RUBBER GASKET,BUT WOULD INVOLVE CUTTING A HOLE IN THE PIPE WITH A DIE GRINDER. INITIALLY THIS SOUNDED LIKE A GOOD IDEA, BUT THE MORE WE THOUGHT ABOUT IT, THE MORE RESERVATIONS WE HAD ABOUT CREATING A POTENTIAL FIRE SITUATION IN A 100 YR OLD ATTIC SPACE. WE ARE OUT OF IDEAS SHORT OF ADMITTING OUR NEGLECT AND STUPIDITY TO OUR CUSTOMER AND REPLACING THE NEW 90% FURNACE WITH A NEW 80% FURNACE AND EATING THE COST. ANY IDEAS OR SUGGESTIONS WOULD BE GREATLY APPRECIATED.
THANKS, ERIC
COMMUNITY FORUM
You shouldn't be tapping into the primarly plumbing vent stack at all.
You are in the wrong forum, there is a well-moderated (the moderator often responds personally to posts) here - higher up on the list for HVAC.
Frankly, from your post you shouldn't be doing this work at all.
You are in the wrong forum, there is a well-moderated (the moderator often responds personally to posts) here - higher up on the list for HVAC.
Frankly, from your post you shouldn't be doing this work at all.
Eric, thankfully you have a lot more common sense then the so called plumber who said use a saddle on the vent line.
It is this kind of advice that causes the legitimate plumbers insurance to go sky high because some non knowing or worse non caring person dabbling in plumbing gets someone killed and then the insurance company has to pay for wrongful death suits.
Saddles are not legal, tying into a main vent OTHER then another vent is against codes and what happens if there is a down draft of the vent becomes blocked with hoarfrost?
(Ask your plumber what hoarfrost is)
Just because someone says they are a plumber does not make it so
Ever go to a bar and see a piano player and they say play it again professor?
Doesn't mean the guy is a concert pianist or a PhD.
Same with the type of mentality that places saddles on plumbing vent system and thinks nothing of using it for condensate.
Same with Fly by nights who dabble in the technical aspects of HVAC and plumbing and electrical
There is a lot more to AC then compressors, condensers, metering devices and evaporators and king valves and high and low side (liquid and vapor)and receivers.
ASME /NBBI would love to see that kind of venting as what not to do
It is this kind of advice that causes the legitimate plumbers insurance to go sky high because some non knowing or worse non caring person dabbling in plumbing gets someone killed and then the insurance company has to pay for wrongful death suits.
Saddles are not legal, tying into a main vent OTHER then another vent is against codes and what happens if there is a down draft of the vent becomes blocked with hoarfrost?
(Ask your plumber what hoarfrost is)
Just because someone says they are a plumber does not make it so
Ever go to a bar and see a piano player and they say play it again professor?
Doesn't mean the guy is a concert pianist or a PhD.
Same with the type of mentality that places saddles on plumbing vent system and thinks nothing of using it for condensate.
Same with Fly by nights who dabble in the technical aspects of HVAC and plumbing and electrical
There is a lot more to AC then compressors, condensers, metering devices and evaporators and king valves and high and low side (liquid and vapor)and receivers.
ASME /NBBI would love to see that kind of venting as what not to do















