Many ductless splits, window and portable units use rotary.
Trane
The unit we are installing next week has a Samsung rotary in it and it is a 2.5 or 3 ton XB I think, will know more when it comes in. It may not come to fruition but with it going to field testing it is very likely that it will.What is Trane using a rotary in? Besides minis and they don't build them anyway, the Chinese do
I am just going on what I was told by the boss man. He may have it wrong..... I will take a peak when the equipment shows up and report back.
They also can take a long time to come around to steady state if they have been off a long time and migrated liquid into the sump - no suction to boil off that liquid as the shell is high side, so the motor has to heat it up.Rotary and Panasonic go together like "Scroll Inside" does with older Rheem units from when Scroll wasn't the standard. Most mini splits are under 2 tons and my understanding is that rotary compressors do better in smaller sizes.
The most common window units are in between 1/2 to 1 ton and they commonly use rotary. They usually don't use high quality brands like Panasonic or Hitachi. They're almost always Made in China. Not just CHINA MADE, but China design/brand as well. The portable unit I have has a " Zhuhai Lingda " brand compressor :gah:
Scroll compressor has no moving parts except for the moving rotor and bearings.
Rotary has a spring loaded vane that rides along the rotor and a discharge reed valve. So, "twin rotary" would have two sets. Rotary compressors usually discharge into the shell, so it is able to deflect discharge gas off baffles and drop the oil back down to minimize oil in discharge stream. Reduced oil circulation improves heat exchanger efficiency.
The suction goes directly into the compression without going bouncing off of the space in shell, so rotaries have a distinctive suction accumulator and a discharge line on tip of the compressor shell.
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In a way that's a good thing. When you have a lot of refrigerant in oil and you reduce pressure on it suddenly, it will foam over like shaken up soda and wash out the bearings. When it's on the high side, pressurization as opposed to depressurization suppresses this. This brings up another question.
Just an observation - it can look like a low charge for 10 minutes or so, then all of a sudden SH & SC will come around.
There's already one in each chamber so the gas it just compressed doesn't flood back in. LG (is it Made in Korea? ) generally makes ok products and I would trust it over some China made with label from a brand you never even heard of.
Rolls back or bit or spins and spins? There's a small amount of gas pocket, so that can push the rotor back into suction side (where there's no valve).
