Minisplit rough in

Thinking ahead and taking a little gamble sometimes pays off.

Despite having not yet decided on the cooling system back in 2012, we decided to rough-in the cooling lines for the minisplit. Back then, I was about to install drywall, and convinced myself that I should rough-in the minisplit infrastructure before I closed up the walls.

I had to decide on the location for the outdoor and indoor unit. I was advised to place the indoor unit in a central location, yet fairly close to the ERV return. The south wall of the dining room met those requirements and had the wall space to accommodate the indoor evaporator.


I was now looking for a fairly short run for the cooling supply and return lines that would connect to the outdoor unit. I opted to mount it on the east facing wall of our building and ran the supply and return lines across the corridor ceiling, the pantry ceiling, and through the exterior brick wall.


An additional advantage of mounting the indoor evaporator on the south wall of the dinning from was that the bathroom plumbing was right around the corner.

Similar to an air conditioning window unit, the indoor evaporator produces condensate when in cooling mode. This is exactly what we want, because this process is reducing the overall indoor humidity. But I also had to figure out a safe way of discharging the condensate. This is where the bathroom proximity came in handy.


I ran a half inch Pex line from the indoor evaporator location over to and down through the bathroom wall. I pointed the line toward the shower drain and terminated it a couple of inches above the bathroom floor.


This way, all condensate is safely discharged into the shower and then drains through the shower drain.

The minisplit was the only cooling option in the picture at that time, and I am glad I opted for the rough-in. It would have been a shame to open up the drywall after everything was finished.

Related post:

Wait and see

Mini what?

Cool ideas?

About Marcus de la fleur

Marcus is a Registered Landscape Architect with a horticultural degree from the School of Horticulture at the Royal Botanic Gardens, Kew, and a Masters in Landscape Architecture from the University of Sheffield, UK. He developed a landscape based sustainable pilot project at 168 Elm Ave. in 2002, and has expanded his skill set to building science. Starting in 2009, Marcus applied the newly acquired expertise to the deep energy retrofit of his 100+ year old home in Chicago.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.