Wall mounting mini-split compressor on a metal building

[Deude_Mann]

So I have searched and read through a few of the threads on wall mounting of mini-split units and resulting vibration noise. Most seem to be about wood framed walls. I am about to install a 24K BTU Pioneer in a metal building and am going back and forth on wall vs ground mount. Either are reasonable options. I don't have to worry about snow or leaves on the ground in my area.

Right now my house A/C is on a concrete pad separated from the house slab. However with the hard ground out here (limestone really) the vibration is transmitted into the house. The situation will be similar for the metal building

So, for those with metal buildings, did you wall mount, and if so, did you have problems with transmitted noise? If you did, was anything done to reduce it and did it work?

Right now for a wall mount I am thinking I would run 4x4 pressure treated wood columns between two horizontal wall purlins, attach the columns to the purlins, and then hang the compressor from that using a DIY wood frame/shelf also made from pressure treated lumber. I ordered the vibration isolators so I would use those at the compressor. The idea with mounting to the purlins is that they would be stronger and vibrate less than mounting to a wall panel.

Thanks

 

[MetalBuildingFun]

We have not mounted our unit as of yet and decided against it because the bracket designed for wall mount would have caused leak issues according the building manufacturer. We are using a quick sling mount for outdoors on a concrete slab but we are also windstorm required to mount a certain way on concrete. We also do have sand because we are coastal and this was the better option for our situation.

https://www.quick-sling.com/minisplitstands

 

[Deude_Mann]

Thanks. I believe I saw those in one of the threads I dug up. IIRC someone was using it to get the condenser off of the ground so it would not be susceptible to leaves and other ground debris.

 

[rok_hunter]

If surface mounting is undesirable because if debris, and wall mounting because of leaks or vibration noise, what about setting two 4x4 posts into the ground and mounting it to those?

Sent from my Pixel 2 XL using Tapatalk

 

[Deude_Mann]

If surface mounting is undesirable because if debris, and wall mounting because of leaks or vibration noise, what about setting two 4x4 posts into the ground and mounting it to those?

Good question... That would be a good way to go in general IMO.

Here the ground is so rocky that to sink posts it takes a rock drill or a jackhammer. As an example I just had to hire a rock saw to dig a utility trench only 18" deep. Most of the ground was large rock, like the size of a car or truck tire. Trying to use a trencher was an exercise in futility.

If I do not mount it to the building, I will use road base (ground limestone) to form a level pad, lay some concrete block or blocks on top of that, and then mount the condenser to the blocks using the vibration isolators.

 

[ticklechicken]

I mounted a pair of 18k Pioneer units to my metal building almost 3 years ago. No issues with noise. Mounting details are in the thread below.

https://www.garagejournal.com/forum/showthread.php?t=370964

 

[Deude_Mann]

I mounted a pair of 18k Pioneer units to my metal building almost 3 years ago. No issues with noise. Mounting details are in the thread below.

https://www.garagejournal.com/forum/showthread.php?t=370964

Thanks for that link. Nice job on the installation. Your details on how well the units cool your building is helpful and based on that I think my single 24K BTU Pioneer will do the job.

Are the unistruts attached directly to the building frame? It looks like it based on the side panel screw locations. It also looks like you used dampers between the compressors and the mount bracket, correct?

 

[ticklechicken]

Thanks for that link. Nice job on the installation. Your details on how well the units cool your building is helpful and based on that I think my single 24K BTU Pioneer will do the job.

Are the unistruts attached directly to the building frame? It looks like it based on the side panel screw locations. It also looks like you used dampers between the compressors and the mount bracket, correct?

I was working in my shop all last weekend. It was around 90° outside, and the shop was 68°. That wasn't the limit, just what I had it set to. I'm definitely over-cooled, but its worth it to get the fast cool down. These units are so efficient, that I never think about the cost. I just turn down the temp until I stop sweating.

I used long bolts to attach the unistrut to the frame. The bolts went all the way to the inside of the building. If you click on the first picture in my linked thread and zoom in, you can see the 4 nuts and washers underneath each interior wall unit.

I used the dampers that came from Pioneer.