Ductless mini-split - how many evaporators?

[exranger06]

I have Mitsubishi Mr. Slim ductless mini-split systems in my house for air conditioning. I have an outside condenser right outside my garage with two indoor evaporators connected to it inside. Can I add a third evaporator in my garage? How many evaporators can be connected to a single condenser? I tried searching online and couldn't find an answer.

 

[chinboys]

certain manufacturers have a central freon control manifold and electronics controller supplement that you put into a central area and then run up to 4 different zones from.
The thing is you cannot exceed the total cooling tonnage or power requirements on this set up by running more zones (splits) than what the system was designed for.
I have a 54K BTU LG condenser that is feeding 3/8 inch liquid to a 4 zone remote box to which I have 4 -9K BTU ceiling units hanging off of returning 3/4 vapor back to the condenser. and I have 3 12K BTU wall units directly plumb into the same condenser manifold with. I will use the upstairs units when I am done for the day but the downstairs wall units will be on while I am wake.

hope this helps

 

[chinboys]

some references on what I wrote about
http://www.supplyhouse.com/LG-PMBD3641-4-Port-Branch-Distribution-Unit
http://www.supplyhouse.com/LG-PMBL5620-MAX-Y-Branch

 

[theoldwizard1]

Just look at the outside unit where the existing pipes connect. Modern ones usually have 4-5 max.

 

[Git]

What is the model number

My outdoor 24k unit can handle up to 3 connections with 2 currently in use.

You will probably have to pull a panel off to see the ports or maybe we can look it up by model number

 

[Muzzy]

I had one installed last fall, and it has three sets of ports.

As mentioned, the way I understand it is that you need to consider the size of the indoor units before adding additional load.

i.e. I have two 18K heads on a 30K condenser, meaning that I'm exceeding the capacity of the condenser with the two I already have despite the piping being capable of supporting a third unit.

 

[Git]

I think it is pretty common to exceed the total capacity - it all depends on how you think you are going to use it. I have a 24k outside unit with an 18k in the garage and another 6 in my adjacent 'office'. I could easily add a 3rd unit and still be in good shape

 

[justinjoyal]

Manufucturer's have their own guidelines when it comed to matching different inside units to multi-zone mini-split systems.

It is indeed common to exceed the rated BTU capacity of the compressor (again following the guidelines).

 

[exranger06]

I snapped a picture of the condenser nameplate

 

[justinjoyal]

I snapped a picture of the condenser nameplate

You can connect up to 3 units to your system. 2 is the minimum.

Up to 36k BTU of rated inside units.

 

[Git]

Yep

I really like eComfort

Scroll down and you will see the specs - including lineset size for the three connections

http://www.ecomfort.com/Mitsubishi-MXZ-3B30NA-1/p30704.html

Also - it looks like you can have up to 230' in lines

 

[exranger06]

Thanks guys. I looked up the model number of the evaporators I have, and it looks like they're 9,000 BTUs each. So I should have plenty of available BTUs for my 440 sq ft garage.

 

[justinjoyal]

Even 12k BTU would be enough but for fast cooling/heating it might a tight fit.