Thursday, September 13, 2018

Installing Our Own Mini-Split System in the Barndominium

Last summer we bought an air-conditioner to put in a window. It did as well as anything in a building that wasn't completely sealed, open to the attic, and had no insulation in the ceiling. In other words, it was only cool right in front of it. Because of that, work inside the barndo came to a halt near the end of June 2017. When it finally began cooling off at the end of September, our momentum was gone and it was really hard to begin working on it again and we didn't work as hard at it once we started back.

During those hot months, we also cleared out three rented storage units and the added clutter made it hard to work. We've completely run out of space to put one more thing in the attic, so anything brought in is either in the way in the house or in the garage. It's hard to decide which area needs to be kept clear more. After we began work again, my main project was to start building cabinets for our tools so we didn't have to spend so much time searching for them or working on the floor. The next time we move the trailer, I'll take a picture of that. While I was building tool organizers, Hubby was wiring, and wiring, and wiring. He still has a few things to finish, but he is on the homestretch with the wiring. The first thing he did was wire the space for the washer and dryer to end our weekly trip to the laundromat, the un-air-conditioned laundromat.

This spring, Hubby decided that we weren't going to shut down when it got hot this summer. We had some bids for central air-conditioning and he had been researching mini-splits, and for our purpose, we decided that mini-splits made more sense. He used software to calculate the size units we would need based on the size of our living space, insulation, windows, and so on, and he ordered one to use as a trial in the attic. If it worked like we hoped, we would buy the rest.



This unit cools in summer and heats in winter.  Hubby was able to mount the inside and outside unit and a hvac technician did the final vacuum and connected the lines.  We mounted this trial unit on the wall between the attic and garage so that later, if it is needed, we can move it to the other side of the wall to heat and cool our garage workshop. 

Hubby installed the outside unit onto the steel wall above the porch awning. Most people set them on the ground, but he wanted to reduce the distance between the inside and outside units, we didn't want them on the ground where they could be damaged by fireants, deer, or the neighbor's cattle, and the awning seems to block what little noise there is. Really, I can barely hear it running when I am standing under the awning and I have excellent hearing. So for that, we are very pleased.

The inside unit is mounted on the wall between the house and garage as close to center as the length of lines would allow. It was recommended that it be in a central location for maximum efficiency. It's hard to tell how well it is working because we have had some gaps over the garage doors and because we only have a half inch of foam board separating that space from the hot garage. If it is turned on in the morning, it can maintain a temperature in the high 70s to low 80s, and that was with the window a/c in the house running also. But if it is turned on when the house was hot and the temperature in the attic is already over 110 degrees, it took hours to get it down to the upper 80s. We felt it passed the test though so ordered two units for the house.

What I am not completely happy about though is that it didn't keep all of the attic at the same temperature. Hubby usually had it set so it blew toward the electrical equipment in the attic and that part of the attic was noticeably cooler than the section directly under and in front of the unit. It does have an option to have the blades in motion which would keep the air moving. In the house, we will also have ceiling fans, which will also help distribute the air.

The two house units arrived in August. Hubby has the outside unit mounted on the wall above the awning with the first unit, and he installed the inside unit in the center of the wall over the windows. Installing the outside unit was fairly simple, he just bolted the frames onto the building's steel wall posts. The inside unit was a little more involved with wiring and condensation hoses. It came with the pipe flared and ready to install. We do have to have an HVAC technician vacuum the lines and do the final test of the unit. With our attic test unit, that was only $100. (Try to ignore the junk under the awning.)



Here's a side view of the unit on the brackets attached to the wall.  The brackets were ordered separately.


I would rather have waited until the whole house was sheetrocked before hanging the inside units, but Hubby wanted to have air-conditioning inside while we insulate. So that's why there is one sheet of sheetrock here with the inside unit. I'm sure the sheetrockers will appreciate air conditioning when they come too. I just hope they can work around this unit because Hubby doesn't want to take it off again.



One unit is mounted on an inside wall, and the lines are in the garage.  When ordering, the lines come in different lengths and are already flared and ready to attach.  The inside unit lines are too long, so Hubby had to order a flaring tool so he can shorten the lines.  We've also noticed a drip or two of condensation, so after we have the siding up there, we'll run a gutter, both to hide the lines and to direct any condensation outside.  So far though, there hasn't been enough condensation to fill a tablespoon, even on the most humid, hot day.  The photo below was taken at a later date but it shows the lines better.

We bought Mitsubishi mini splits and spent between $1500 and $1800 on each unit.  The hvac technician was $100 each time he came out, and he came out twice.  That makes them half the price of the central heat and air systems we were quoted.


We hadn't planned on working on that upper wall since it isn't critical, but one of our bay lights already quit working, so it looks like we will be renting a scissor lift soon.

We're not quite ready for insulation, but we are going to buy it tomorrow anyway, and not just because we need more stuff in our way. We'd like to avoid the extra expense if Hurricane Florence causes a price hike in building materials like past hurricanes have done.

1 comment:

  1. These air con units are well worth their weight. I have two one for up and one down in my small house. Even in the UK they are starting to prove their worth with such erratic weather and horrid summers.
    ERin

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