Mini split ceiling cassette condensate

[makemenuconfig]

I've got my mini split installed, went well. Pulled down to 150 microns, with a rise to 200 after a few minutes, and held for 20 minutes after that. We've got heat which is very nice.

Now I need to run the condensate line. This is a ceiling cassette with an internal condensate pump. I wanted to add this inline combination cleanout and float switch (link) to shut off in case of clog. But as I think about it, without a vent or way to let air in I don't think it would work. Wouldn't the pipe pretty much always be full of water and therefore cause the float switch to float?

This is in my attic. I will insulate the condensate line, but my preference would be for the downhill piping to not be full of water year round. Should I add a tee to vent this line so it can drain out every time? Is there any kind of valve (like a mini AAV) to ensure water wouldn't pour out in case of a backup?

 

[PoorUB]

Just add a tee with one leg pointing up a foot or two.

I would recommend building an insulated box over the unit, to keep it from freezing.

 

[Mr onetwo]

like this...I wouldn't use the device you linked

 

[fitter30]

Put the tee on the horizontal pipe it up 12" over and down into pan or bucket. Wire it in series with S1 between condenser and indoor unit.

1502C Condensate Overflow Safety Switch - Beckett

The in-pan condensate overflow safety switch serves to prevent the pan from overflowing, while offering reliable equipment shutdown.

beckettus.com

 

[jthemmer]

Unless that is some janky brand you will not need that. Name brand cassette mini splits will run the pump initially on each start up to verify operation before bringing on heat or cool and they also shut down if that pipe ever clogs up. Make sure to insulate your condensate line. Pvc will sweat in the summer above a finished ceiling.