installing mini split AC

Old 04-23-19, 01:28 PM
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installing mini split AC

I have 2 questions for installing a mini split: supporting the outdoor unit, and electrical wiring for conduits.

MECHANICAL SUPPORT. I'm deciding where to install the outdoor unit. There's about 30 inches between the outer wall of the house, and a 3 ft wall separating my property from the neighbor's. I think it's not enough air flow to simply put the unit on the ground, so I'm considering either a wall bracket or a ground support that is about 3 ft tall.

The wall bracket may transmit some extra vibrations to the inside of the house, and also I'm not convinced with the brackets I saw for sale online (plus having to find the studs and drill through stucco).

On the other hand the only commercial ground support that is 3 ft tall and is capable of holding about 80 lbs costs hundreds of $.

Can you suggest a reasonably priced alternative? For example, do you think it's feasible to use something like cinder blocks or heavy duty workhorses with a pad on top? They sell pads for AC outdoor units but they are meant to be leveled on the ground. I wonder if I could level them on top of a stable support. I worry it might be too unstable, and I'm thinking the bracket might be safer. I read some brackets are angled backwards towards the house wall. Is that OK? I read the condenser should be level.

CONDUITS: My other question is about the wiring for the 2nd AC unit that would be in the back of the house, while the electrical panel is at the front. The wiring will go about 40 ft to carry 230 V on a 20 A breaker. I think AWG 12 should do it? Also, since there's a lot of ivy and obstacles around the side of the house, I'd probably prefer not to attach a conduit to the wall to carry the refrigerant and power lines to the back, but rather put the refrigerant in a conduit on the ground, and about the power lines: is it OK to use a flexible conduit instead of a rigid one? I read Romex is indoor-only. Is there an equivalent for outdoor? Or can I just buy a flexible conduit and put some THWN wires in it? I'm in Southern California so the wires would have 2 lives carrying 120 V each. Though I live in the city, there are all kinds of critters walking there (cats, squirrels, opossums and raccoons) so perhaps putting conduits on the wall might be better?

Sorry I may sound a bit ignorant but I worked with high tech stuff before in a scientific environment, I'm just a bit unfamiliar with American standards and house engineering. I appreciate your help in getting up to speed.

Last edited by CaliBear; 04-23-19 at 01:52 PM.
Old 04-24-19, 05:34 AM
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As far as suporting the unit you could use cinder blocks but they would have to be on a proper stable base and be mortared in place to be a permanent support.
You can not just loose stack them.
If you prepare the ground properly and build this structure as you should the few hundred dollars for a pre-made metal stand may make more sense.
Old 04-25-19, 06:21 AM
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