Ductless mini-split condensate drain
Hi all- I have two ductless minisplits installed in a new construction residence. Both indoor head units have gravity condensate drains. I now need to determine how to terminate these drains. I live in a cold climate (New Hampshire).
First option is to drain outside the building envelope and add waterless traps to prevent air infiltration without concerns of the traps freezing. https://www.johnstonesupply.com/product-view?pID=B18-107
Second option is to drain through the basement slab into the crushed stone below. I have an interior perimeter drain/vent for radon reduction, so I expect I would still need a trap in-line to prevent radon/air moving up the condensate line when the units are not in use.
Anything I’m missing here? Which would be the preferred drain method?
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Replies
Outside. Squeeze a chunk of that ridge vent material that the name is escaping me...to keep the bugs out. Minisplits don't like traps.
Definitely not under the slab. Another option is into a regular drain.
Ok, so far the consensus is- drain the condensation outside. (Unfortunately there are no nearby interior drains I could tie into for these lines). So, is there concern about air infiltration through the condensate lines if no trap is used?
?? In heating mode the outdoors are condensing.. the indoor drains can freeze all they want - they are not used…
If there's any water in the drain line it can burst the line. That's the problem with having traps.
I usually put them into the riser for the washer or into a floor drain. Outside can work but willl get algea growing on the concrete there eventually, you can also have a spider make a home in it over the winter which can plug the drain. Outside drains are very common, so it does mostly work.
Columbo,
You may find this article useful: https://www.greenbuildingadvisor.com/article/how-to-prevent-condensate-leaks-from-ductless-heat-pumps