u/999Doom666

Hi everyone,

I’m hoping someone here who owns a DREO 516S portable air conditioner can tell me whether this behavior is normal or if something is wrong with the unit.

I originally bought a DREO 516S because the reviews were very positive, especially regarding its cooling performance and relatively quiet operation.

Unfortunately, my first unit clearly seemed to have a problem. The compressor would only cool for relatively short periods and then suddenly stop with a very noticeable loud “clunk” or cracking sound. After that, the unit continued blowing air, but the air was no longer cold.

This happened even though the room temperature was still around 28–31°C (82–88°F) while the AC was set to 16°C (61°F) in cooling mode.

So this was definitely not a case of the room already reaching the target temperature.

I contacted DREO support, documented the behavior and eventually received a replacement unit.

The replacement is definitely an improvement in one respect: it operates noticeably quieter than my original unit, which confirms that the first one was probably not completely normal.

However, the replacement unit still shows basically the same compressor behavior.

The compressor starts cooling normally, the outlet air becomes noticeably cold and the room temperature starts dropping. After some time, however, there is suddenly a fairly loud clunk/crack from inside the unit, and immediately afterwards the actual cooling stops.

The fan continues running normally, but the air coming out is then basically just room-temperature air again.

After a fairly long period, the compressor starts again and the same cycle repeats:

Compressor starts → cold air → room temperature drops → loud clunk → compressor/cooling stops → fan continues → room temperature rises → compressor eventually starts again.

With my previous unit I recorded a roughly 45-minute video showing this behavior very clearly.

For example:

• Around 2:20, the compressor/cooling starts.
• Cooling continues until approximately 8:24.
• At about 8:24, there is a loud clunk and the cooling suddenly stops.
• From approximately 8:25 until 30:00, the unit mostly just blows air and the room temperature rises again.
• At around 30:00, the cooling starts again and the room temperature steadily decreases.
• At approximately 36:26, there is another obvious clunk and the cooling stops again.
• After that, the fan continues running while the room temperature starts increasing again.

The replacement unit behaves very similarly, although it is generally much quieter.

The AC is standing on a flat and stable floor, the air filters are clean, the air intake is unobstructed and the exhaust hose is properly connected and exhausting hot air.

What confuses me most is the long period during which the compressor remains off even though there is still a huge difference between the room temperature and the set temperature.

For example, if the room is still close to 30°C while the AC is set to 16°C, I would expect the compressor to keep cooling much more consistently.

So I’m wondering:

Does anyone else with a DREO 516S experience this?

Is this compressor cycling and the fairly loud clunk when the compressor stops considered normal for this model?

Could this possibly be some kind of compressor protection cycle, thermal protection, refrigerant pressure protection, defrost cycle or another built-in safety mechanism?

And if it is normal: how long does your compressor normally stay off before restarting when the room is still far above the target temperature?

I’d especially appreciate feedback from people who actually own the DREO 516S or a similar DREO portable AC.

I really like the design and features of the unit and I would like to keep it, especially since the replacement is noticeably quieter. But before assuming this is simply how the unit is designed to operate, I’d really like to compare it with other owners.

Video showing the compressor/cooling cycles:

SwissTransfer:
https://www.swisstransfer.com/d/98ed7792-aaeb-40c1-801e-8cecbd18855d

Thanks a lot for any experiences or technical explanations!