Locating an HVAC condensate drain in a Passive House
What is the best approach for dealing with condensate drains in a Passive House?
We will have 3 mini split cassettes on the main floor and one for the basement for the Passive House we are building in Maine. See our blog at www.EdgewaterHaus.com.
Options we have considered so far:
- Standard local practice is to bundle the condensate drain with the refrigerant coil and control wires directly outside. Unit drains in summer A/C, not in winter heating so no freezing concern. We don't like this approach because the condensate tube is an air pathway into the house.
- Tie the condensate drain into the interior perimeter drain in the basement. The perimeter drain will also serve as a radon vent if needed after construction is complete. We don't like this approach because it again leaves an air pathway, albeit underground to a storm water main, into the house. Unclear if code would even allow this.
- Tie the condensate drain into the waste line in the house. This is our preferred approach as it eliminates an outside penetration, and would use the plumbing trap to air seal the path back to the wall cassette. The downside is the need to snake a 3/4" line up to 30' with proper slope through interior walls to reach a plumbing waste line.
Are there other options? Are air admittance valves possible for use in the first two options?
Posted Aug 23, 2012 9:33 PM ET
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