Context: I am not a fridgy, I work with electronics. I would love to answer my question by tearing open a dozen different aircon units, but I’m sorely lacking in that department.
Question: Are there some optional components or fancier materials that are simply too expensive to use in the lower end aircons; but are used in the higher efficiency expensive units? The range of COP/EER I see advertised is wild, from 2 to 6 or so.
I already vaguely understand that these things help efficiency:
- Bigger indoor & outdoor coils with more metal in them (working fluids get returned hotter/colder gives better carnot efficiency)
- Operating compressor at its optimal power level (I believe they have an efficiency vs power curve with a single peak, so it’s better to use a bigger compressor if you need more power output)
- Inverter control instead of on/off control (most situations, but technically some use cases will have them on par)
- Choice of refrigerant (but that seems to be controlled in my market, I have not seen many options)
Is there anything else they change? Or is that most of the difference?
You should check out the Youtube channel “technology connections”. They have videos that go into detail about heat-pumps. Specifically what the efficiency ratings mean, and how different units compare.
Oh, he’s done episodes on heat pumps? I’m gonna check that out. I weirdly loved an episode about can openers. The guy has a weirdly all access tv way of explaining things really well.
He loves heat pumps! Huge proponent of them!
I don’t think I’ve seen variable speed fans and compressors mentioned. If the thermostat can learn the heat loss/gain it can let the compressor/fan spool down to use less electricity occasionally. Also not all motors are at peak efficiency while they’re at peak speed, so slowing it down can reduce electricity usage more than it reduces heat transfer.
Eta: variable speed can also prevent cycling where the air conditioner runs full blast for 5 minutes an hour because it’s oversized or not hot enough outside.
In addition to advances in fin design and compressor and motor efficiency and materials, there’s also the option to use things like heat pumps instead of traditional compressor based ac systems. They tend to be more efficient or for the same size to produce more cold air for the same electricity.
Due to the fact that a heat pump moves heat and it is not a unidirectional process like a traditional compressor system is, heat pump air conditioning systems can be both heaters and coolers at about the same electrical efficiency.
heat pumps instead of traditional compressor based ac systems
Heat pumps are compressor based systems. They are the same technology.
In addition to advances in fin design and compressor and motor efficiency and materials
This reads lot like an answer from an LLM. Did you use one? My apologies if not, but you sound very suspicious.
No I didn’t use an llm and yes a heat pump does use a condenser or a compressor but it’s not the same as a Freon based compressor system.
Yes, heat pumps use probably a Freon based refrigerant but they operate in a slightly different manner.
How is being a heatpump (a reversible air conditioner) automatically more efficient?
If you have 2 units using identical design, but only add a reversing valve, I don’t see how the heat pump version would be any more efficient at cooling.
