Tom, what does a Florida boy have to say about https://www.askmehelpdesk.com/heating-air-conditioning/protect-condensate-drain-freezing-45619.html

Labman,

I knoth nothing about condensing furnaces or even how they operate but it's not difficult to see that bkspero focused on the condensate drain line while Northern Heat correctly focused on the condensate pan itself. At -15 degrees the water in the pan would freeze before it ever got to the drain line.
And speaking of drain lines, in my area it's against code to discharge, roof drains. Water softener discharge or condensate lines into a public sewer. So his idea of just discharging the condensate into a existing attic vent would technically change that vent from a vent stack into a stack vent and in doing so would render all the fixtures venting into it out of code.
In my opinion he has two options, (1) Insulate and heat the attic room the heater's in **or**(2) move the furnace.
Nice hearing from you Lab. Regards, Tom

I knew our plumber is a Florida boy and usually avoids furnace questions, but thought discharging into the vent might be a problem.


Labman,

I knoth nothing about condensing furnaces or even how they operate but it's not difficult to see that bkspero focused on the condensate drain line while Northern Heat correctly focused on the condensate pan itself. At -15 degrees the water in the pan would freeze before it ever got to the drain line.
And speaking of drain lines, in my area it's against code to discharge, roof drains. water softener discharge or condensate lines into a public sewer. So his idea of just discharging the condensate into a existing attic vent would technically change that vent from a vent stack into a stack vent and in doing so would render all the fixtures venting into it out of code.
In my opinion he has two options, (1) Insulate and heat the attic room the heater's in **or**(2) move the furnace.
Nice hearing from you Lab. Regards, Tom

I would talk to Goodman. They could come back with no deal on an attic installation, or they may be aware of the problems and have a code compliant fix. If they say they can do it, get the details and let Tom and Northern Heat know. Even run the electrical work by tkrussel in E&L.

I knew our plumber is a Florida boy and usually avoids furnace questions, but thought discharging into the vent might be a problem.



I would go ahead and talk to Goodman. They could come back with no deal on an attic installation, or they may be aware of the problems and have a code compliant fix. If they say they can do it, get the details and let Tom and Northern Heat know. Even run the electrical work by tkrussel in E&L.

I'm the original poster on this topic. I spoke with Goodman and they are OK with an install in an unheated attic. Only caution is to keep the water in the condensate trap and drain line from freezing. It is also discussed in the installation manual.

I asked them about water freezing in the heat exchanger and primary condensate pan and they laughed at me. Told me that the only time they have water on them is when the furnace is running... and the temperature had better be above freezing ;-}. They told me that any water in the HX and primary condensate drain pan flows into the condensate drain well before the unit cools below freezing.

As for draining into the stack. Could the reason why the Plumbing Inspector has approved it be that we are on a septic system and not draining into a sewer line? I don't think that he overlooked it. Our local contractors tell me that our township's inspectors are pretty strict. And I both spoke with him about it and provided detailed arrangement drawings with the permit application.

I appreciate your insight and would prefer to address all of these issues prior to starting the project. Thanks again.