I unexpectedly had to switch gears to a different project, leaving the insulation and security system wiring as yet incomplete. As I mentioned, the HVAC installation has started, and one of the downside to having mini-splits is that each unit needs a drain line, as opposed to central air, where you only need one because you only have one evaporator. In discussing where to run the lines with the installer, he originally suggested along the beam in the first floor, which would involve padding it out further to allow the 3/4″ line to fit. Unfortunately, that wouldn’t work in the basement. While it could run along the beam, it couldn’t jog over to the mechanical room without dipping below the ceiling, since drains need to follow gravity.

I realized the simplest solution would be to run a drain line through the basement along the outside wall above the curb. When we eventually finish the outside walls, it will all be covered up, and it could pick up each of the units on the way, plus I wouldn’t have to pad out the beam, save one section in the back.

New drain in the mechanical room

While I could have asked the installer to do this work, because it was in the basement doing so would mean more time we couldn’t be living and working here, and more stuff that I’d have to move, particularly in the kids bedroom where they have a lot of stuff, much of which is currently scattered across the floor. While cleaning their room is long overdue, moving shelving and dressers and more to give them access wasn’t appealing. Instead, I could just run this portion myself and they can connect the units.

With a plan in motion, I ran to Menards and picked up a bunch of 3/4″ PVC, 1-1/4″ PVC and a plethora of fittings. I told the installer on Friday that I could knock this out over the weekend so that it would be ready for them when they come back Monday. Saturday morning, I started in the mechanical room, and it took about ten minutes before I discovered I’d need more fittings. Now, if there’s one truism of DIY, it always takes more trips to the store, but I’ve learned an important tip: don’t go yet. If you go to the store every time you realize you need parts, it will take many trips. Instead, get as much done as you can with the materials you have, discover all the things you need along the way, then make one trip. At least, that’s the idea.

Running along the curb in the basement

The next challenge is that the installer and I had discussed the drain line coming down the outside wall in the first floor between the two kitchen windows. I quickly realized that in the basement directly below that is… a window. One upside is that I realized that instead of having separate lines going up to three units (basement unit, first floor unit, and attic air handler), I could have them share a single line because they’re fairly closely spaced. The downside to that was I then wanted to use the larger 1-1/4″ pipe for the vertical run, since it was multiple units. Here again, I discovered the need for more/different fittings.

Ready for the basement unit

I figured out a narrow path that the drain pipe could take to come between the windows upstairs and then to one side of the window in the basement, but it was a really narrow space upstairs. Cutting out expensive spray foam to get this installed upstairs underscored that I really should have planned for this months ago. We can backfill with canned foam, but it’s not as good. Fortunately, these are all really small spaces.

Complicated bends in a narrow space

After another trip to the store, I made some good progress getting the line installed. I added the boiler condensate line as well, since that had a hose that would often slip out of the drain and (since the basement floor isn’t sloped to the floor drain) lead to a puddle in the mechanical room.

Connected to an air handler in the first floor

It picked up a drain coming down the wet wall from the unit in the back of the first floor, then into the basement family room where it goes and picks up the aforementioned three units, running clear up to the attic. Lastly, I ran a 3/4″ line clear to the front of the house to pick up the unit in the front of the first floor. I got everything installed, sloped, anchored to the wall, backfilled the gaps with canned foam, and cleaned up the rather large mess I’d made cutting out channels in the spray foam. It was a busy weekend, but it’s done. Now I can switch back to the other projects that need to be done before drywall can go in.