Elevating Outdoor Minisplit Unit
DarkNova
| Posted in Mechanicals on
We’re looking to heat with minisplits in a snowy climate and I know the importance of keeping the outdoor unit elevated above the snow. I’m trying to figure out a solution for elevating the unit at least 3 feet from the ground in order to accomplish this. I know we could use a wall bracket, but I’ve read several reports about vibration being transmitted through the structure, so I’d like to avoid that if possible by mounting on an elevated pad. Has anyone seen a stand to elevate a minisplit at least 3 feet, or has anyone site built such a thing? Thanks.
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I've seen several site-built platforms for keeping the exterior unit above the snow line, usually a combination of CMU & steel.
I've also seen plenty of the plastic & aluminum types being used too:
http://www.fencespecialists.com/wp-content/uploads/2010/12/snow-shovels.jpg
;-)
Ya I figure many people use the plastic ones but I'd like to avoid that if possible with good planning :-)
Nick,
Here are some photos to give you some ideas.
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Thanks Martin
Nick,
More information on the wire stand under the Fujitsu unit come from the web site where I found the photo. The web site is:
http://www.aabbottferraro.com/mini-splits/outdoor-units/
Here's the info: "The free-standing wire stand is attached to a plastic pad that is placed level on the ground. The Fujitsu ductless mini split is then bolted to the wire stand. These stands are unique to our area because they are made by a contractor in southern Minnesota that only sells them locally. Wall brackets are used when we cannot use a wire stand."
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I suspect the structural vibration complaints are way overblown. I certainly haven't heard anything from my own units installed on brackets or on other local jobs where the installer has used brackets. If I want to know if the compressor is running, I have to go outside (or look at a power meter or hold my hand up to a register).
They are not overblown. I am living with this problem and desperately want a solution. I have tried speciality vibration isolation mounts and bolt isolation. No Luck. The vibration/noise is annoying. I am looking for a solution that will allow me to mount my mini split system about 3-4 feet off the ground as the wall mount is causing a vibration/noise problem that is disruptive.
I have a similar 4 ton Mitsubishi unit -- I'm glad I had the contractor switch to a stand versus a wall bracket as I had originally planned. It seems to vibrate much more than I expected it to at certain speeds.
Same here. Ours looks very similar to your setup.
Our contractor actually recommended the ground stand b/c of complaints about noise for wall mounts. They installed the outside unit on wire stand to get it out of snow.
We live in snow country and have a mini split on brackets on one of our walls, installed by a Mitsubishi certified contractor. Maybe there is some glitch in our installation or a characteristic of our walls (double stud 2x4, 16" OC) that causes it, but i can confirm noticeable noise and vibration...depending on how strong the unit is running.
It's not enough that I'm going to hire the contractor to re-mount elevated on the ground (although I thought about it), but if building again, I would go with ground mounted on a pad/stand.
Maybe it has something to do with the units working harder to keep up in cold/snowy climates?
I have the same problem. The vibration/noise is annoying. Did you solve this? I am looking for a solution that will allow me to mount my mini split system about 3-4 feet off the ground as the wall mount is causing a vibration/noise problem that is disruptive.
We've gotten used to the noise/vibration and are ok with it for now. When/if we have to replace or do major maintenance to the mini-split, I will consider re-configuring to a pad/stand setup.
Ok, now do any of you have vented gas fireplace that vents out anywhere near the mini split?
Hi,
I am looking for a solution that will allow me to mount my mini split system about 3-4 feet off the ground as the wall mount is causing a vibration/noise problem. Did you ever find one?
You could potentially build a wooden stand, but I’d use steel. You could have a fab shop weld up a simple stand and powder coat it, or you could build your own stand with strut. Strut is a steel channel system that is used to build all kinds of mounts and brackets commercially. You can get the basic parts at the box stores in the electrical section, usually in the cheaper green epoxy finish or in galvanized. Through commercial electrical supply houses you can get other finishes and even stainless steel.
Anyway, it would be simple to construct a stand using strut and angle brackets (the angle brackets made for strut are made from 1/4” thick steel and are very strong). It would probably be maybe $200 in parts. Pour a small concrete pad as a foundation and bolt the strut to that. Note that if you use square washers (another strut system part) as spacers to keep the strut channel up a little from the concrete, you’ll keep the strut from sitting in puddles and you’ll drastically decrease any rusting.
Bill
Hi Bill,
Thanks for your advise. I am going to investigate your advise. I am hoping the area I need to dig out is clear of ledge and other obstructions to get past the frost line here in Massachusetts. Since the area is adjacent to the existing house foundation I am thinking it will be! Do you have any thoughts on using steel helical piles instead of cement? Here is a pick of the current install.
Thanks
Josh
I'm wondering if your vibration issues have anything to do with how close the unit is to the wall. That has to be less than the minimum clearance, doesn't it?
You can probably just use a concrete pad, but it wouldn’t hurt to go down to the frost line. I see no reason you couldn’t use helical piles, just make sure you’re far enough out from the foundation that you don’t crunch up the foundation when the pile is screwed in.
If you use helical piles, you could probably get a fitting to allow the strut to be directly bolted to the tops of the piles. That might make for a cleaner appearance. Note that while many people use strut pipe straps for mounting to round things, the pipe straps really aren’t structural and shouldn’t be used for this application.
Bill
You don't need much for a base. A couple of patio pavers will work well enough. You do have a very tall unit, I would make sure that it can't tip over. Helical pipes would also work great as you adjust how far they are driven in to get a level platform.
I've made a stand before out of some 16 gauge 2"x2" galvanized steel angle. Easy to work with as you can just screw it all together with a bunch of TEK screws. Just make sure you add diagonal braces in each direction.
Preventing the vibration from getting into a stick frame wall is futile, it is too light and flexible. I've tried a bunch of isolators, never good enough. I think about the only way to make it work is to suspend say a 200lb concrete slab on the wall, then mount the unit to that with proper isolators. Ground mount is the way to go.
A trick I’ve used in the past to keep stuff from tipping over is to get some of the screw-in earth anchors like are used to guy fences and poles. These are like extra beefy tent stakes, but with a screw on the end of a steel rod and an eye that stays above ground. Tractor supply stocks them in several sizes and I’m sure they’re not the only place that does.
Screw in an anchor or several and fasten them to the frame. For small stuff, a single anchor in the middle TIGHTLY connected with rope or chain works well. For larger things (which would include the outdoor condenser stand we’re discussing here), at least one anchor on each of two sides is best.
Bill
Hi Josh-
Did you ever find a solution/stand you are happy with. I'm dealing with the same situation here.
Bill
Hi, thanks for the reply back. I didn't intend to delete my initial reply but using a smartphone somehow managed to delete vs reply. Anyway, glad your issue was fixed. I'm working on mine still, waiting for Mitsubishi to call back for site visit...i'm not holding my breath!
Happy new year -
Deleted
I ended up moving (having moved) the units from the wall-mount racks to 18" Quicksling stands on 4" pads. Noise (the same heavy rumbling you decide, sounded like a diesel truck idling in my drivewar!) is gone. OTOH, there *may* be vibration transmitted through the lines. As I understand it that is more difficult to alleviate.
I see no reason to install a foundation for a mini split stand. Should frost lift the rack it is not a problem it will settle back when it thaws, the pipes and wires should flex enough that unit can move.
If you want the stand completely detached from the house with the unit 4 feet off the ground the top of the unit may be 7 feet above the ground. I would want the stand bolted to a 4 inch thick concrete pad on top of 4 inches of gravel.
My friend Google found this stand when I asked “tall mini split stand” You may also want to load the lower shelf.
https://www.h-mac.com/quick-sling-qsms1203.html?gclid=CjwKCAiAh5_uBRA5EiwASW3Iaqu_38bfRLOyeT49yG9Sg8T6j0VJPlrTVzFVhQwv4vy39xm8xW5AFBoCJZYQAvD_BwE