multiple mini-split planning....

[jpcjguy]

Hi all,

So this initially started as having a mini-split for my upstairs room in the detached. Here is the thread on that: mini-split sizing for upstairs

But.....since the plan is to eventually add 1-2 units for downstairs it got me thinking about the outdoor unit(s) location.
The garage is 48x30 with a lift side and a 10' ceiling side on the other side. The walls are 12', but the room trusses use a 2' raised heel to give more space for upstairs.
Garage is fully insulated. Here are pics from the inside with the red boxes show where 2 units would go - one for each side of the garage OR get a big unit and center it on the back wall (green box in pic)?

Which bring me to my back wall planning for condensers. My original thought was to mount them high on the wall to keep them out of the way, but with reading about vibration, I am now hesitant about it....
In the pic below you can see the location of the potentially 3 condensers, 1-2 downstairs, and 1 for upstairs.
The wind also can be pretty strong but luckily it is parallel to the back wall so not directly into the condenser.

Any thoughts or ideas? Would a single single unit downstairs be fine? If I do a ground mount, can I just get the prefab pads?

Thanks!

 

[pcmeiners]

"My original thought was to mount them high on the wall to keep them out of the way, but with reading about vibration, I am now hesitant about it...."

Since it is a garage you might be able to live with the noise. Now it not only the DB level but the frequency (s) you have to live with. Minisplit have odd frequencies some times, not very nice. If you put them on a concrete slab, mounted at least 6-12" ( for snow, leaves, rodents), you would be hard pressed to hear them if at all.

Wind.... If wind does create an issue you could plant to form a wind break. I have heavy wind which are perpendicular to my (3) units for my home, I placed the units perpendicular to the house, so it is not an issue. For my garage, wind is blocked by the back of my garage so it is no problem at all.

Checked out prefab pads, waste of money, get Sackcrete, and hire a kid for a day to mix. Mounted mine about 12" off the slab on 4x4" hollow composite posts (Home Depot), filled with concrete, with stainless bolts set in the wet crete. There are 2 kinds of posts, PVC and composite, PVC is weak.

Lastly I mounted them a bit close to the house wall which did not leave a decent space for lineset , also leave the required space between units or walls.

Smaller individual units are more efficient, provide quasi zoning, provide backup should a unit fail, also you will not have emergencies to get heat or cooling at the wrong times.

 

[Jackfre]

I wall mounted a two ton dual and a single 12 on my last home. I could hear it just inside the room, but it didn’t bother as it was not an occupied bedroom. I like the wall mounts. In Richmond you don’t geet a lot of snow so mounting a foot off the ground should be sufficient. The higher you can get them off the ground the cleaner they will stay. Can you do it with a single unit. 1500 sq ft in your area a 2.5 or 3 ton unit would work but 50’ is a long throw. I had really good luck with a 3 ton Fujitsu ceiling suspended unit in large open spaces. If you go hi-wall read the instructions. Remember the actual room stat is mounted on the evap coil. Set them to high and your temp calibration is going to be off. 7-8’ is best. Makes it easier to clean as well.