Roof Mounted Mini Split AC

[Skramy]

I'm considering mounting the condenser of a dual mini split system on the garage roof of my bilevel. (If condenser was on the ground I would have a 20ft and 35ft tubing run).

IF I mounted the condenser on the garage roof I would have a 6ft run to the upper room and a 15ft run to the lower level room. HOWEVER, the run to the lower level room would be straight down. A drop of about 12ft.
Is that a no-no having the condenser higher than the indoor unit?
Is it especially a problem for a dual unit?
SteveS

 

[justinjoyal]

Should not be a problem for such short runs.

Check the unit's specs, they usually indicate max height difference, max piping lenght, etc.

 

[Jackfre]

Make sure you understand the specs of the manuf you are using. Some have minimum line set lengths. My Fujitsu's require 9" of the smaller evaporators and the larger, 24kbtu+ look for min of 12'. I roof mounted one of the units in my home. We built a plywood box graded for drainage that was flashed into the roof. It is quite a flashing, but fun to build. I then took some 8" channel and used it for standoffs and attached the contending unit to it. Make sure the condenser is level all the way around. You want the stand-off height for drainage in the defrost mode and snow clearance.

 

[Skramy]

The specs in the manual state: Max Drop Height = 10m (33ft).
That's all could find. I'll search for more info.

Jackfre - Have any pics of your roof mount? Was yours a single or dual? How long tubing run, and have any height diff between indoor & outdoor unit?

 

[Jackfre]

No pics. Just close your eyes and imagine it while someone reads you the description. There are all kinds of ways to do it. Airtec may have roof kits. In my home I have the single 15 roof mounted a single 12 wall mounted and a dual 24 wall mounted. Vertical rise is less of an issue on the inverter 410A mini-splits. The expansion valve is in the condensing unit and while we still call them liquid and suction lines on the inverters both lines are gas lines and aren't as susceptible to slugging

 

[DanielWhite]

Mini-splits provide solutions for many applications. The big advantage is how quiet they are. I have used a little portable $300 around 9000btu wheeled with exhaust ac unit in my van a couple times and it worked fantastic!

 

[Falcon67]

Should not be a problem for such short runs.

Check the unit's specs, they usually indicate max height difference, max piping lenght, etc.

X2 - we have a 9K at work in a network closet, condensing unit is on the roof, closet is on the first floor of a two story building. So at least 15'~20' above counting turns and vertical rise.