Originally Posted By: sramos
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Steven Ramos
EnviroVue Home Inspection
866-541-2883
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Originally Posted By: Brian A. Goodman
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As far as I know the answer is “never” due to possible cross-contamination, but I see it here and there. I write it up and tell 'em to run it to the exterior like they’re supposed to. Some do it, some don’t.
Originally Posted By: Phillip R. Smith Sr.
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There is a proper way to tie it into a drain line. This is not it. You have to have a trap and a air gap.
In my area if the trap it ties into is 1 1/2" it had to be 2’ deep.
Most time it is cheaper to run it to the exterior.
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Have a good day inspecting.
Phillip R. Smith Sr.
Samantha (Tuscaloosa) AL.
Originally Posted By: rpalac
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Phillip is correct,
The IPC (international Plumbing Code) allows the indirect connection.
It physically must have a trap and an air-gap that is calculated by x times the diameter of the incoming pipe. (I don't have my book as a reference)
The reason is so there is no bacteria contamination or possibility of siphoning.
Bob P.
Originally Posted By: sramos
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I assume you mean cross contamination by siphoning gray/black water back to the coil? Causing bacteria to grow and contaminate the house air supply?
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Steven Ramos
EnviroVue Home Inspection
866-541-2883
Originally Posted By: Blaine Wiley
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It is not allowed here by the utility company. Only city water is allowed back into the sewer system. They call it unregulated water.
Originally Posted By: Brian A. Goodman
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Cross-contamination also includes gases. I haven’t known it to happen myself, but with no trap the path is there for sewer gases to be sucked into the air distribution system (most HVAC systems being under negative pressure).
I'm no plumbing guru, so pardon me if these are silly questions, but...
If you have an air gap, what's to stop sewer gases from leaking into the attic? Isn't there some prohibition against that in the code?
Originally Posted By: rpalac
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Another option I neglected to say is the use of a check valve. i believe in the IPC it is allowed.